Lens assembly and design method thereof, camera module and electronic equipment

Abstract

The invention discloses a lens assembly and a design method thereof, a camera module and electronic equipment, and relates to the technical field of electronic equipment, the lens assembly comprises a substrate layer and at least eight super-structure lens unit groups arranged in an array, the super-structure lens unit groups are arranged on the substrate layer, each super-structure lens unit group comprises at least two super-structure lens units, and the super-structure lens units are arranged on the substrate layer. The deflection angles of the at least two super-structure lens units in one super-structure lens unit group are different, so that the at least two super-structure lens units are focused under different focuses, and the at least two focuses of the at least two super-structure lens units are combined to form a lens focus of the lens assembly.

Description

Technical Field

[0001] The present application belongs to the technical field of electronic equipment, and specifically relates to a lens assembly and a design method thereof, a camera module and an electronic device. Background Art

[0002] Depth of focus is an important characteristic of mobile phone lenses. Depth of focus refers to the distance the focus is allowed to move along the optical axis of the lens while keeping the image relatively clear.

[0003] The depth of focus varies with the focal length and aperture value of the lens. When using a telephoto lens to shoot distant scenes, it is often easy to lose focus due to the small focal depth of the lens, and the subject is out of focus, resulting in blurred images. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a lens assembly and a design method thereof, a camera module and an electronic device. By using a multi-focus fusion method, the lens will have a larger depth of focus, thereby ensuring the focusing accuracy of the telephoto lens.

[0005] In a first aspect, an embodiment of the present application provides a lens assembly, comprising:

[0006] basal layer;

[0007] At least eight meta-lens unit groups arranged in an array are disposed on a substrate layer, wherein the meta-lens unit group includes at least two meta-lens units, and the deflection angles of at least two meta-lens units in one meta-lens unit group are different, so that the at least two meta-lens units are focused at different focal points, and at least two focal points of at least two meta-lens units are combined to form a lens focus of the lens assembly.

[0008] In a second aspect, an embodiment of the present application provides a camera module, comprising a lens assembly as in the first aspect.

[0009] In a third aspect, an embodiment of the present application provides an electronic device, comprising a camera module as in the second aspect.

[0010] In a fourth aspect, an embodiment of the present application provides a method for designing a lens assembly, which is used to design a lens assembly as in the first aspect, and the design method includes:

[0011] Obtaining the deflection angles of at least two metalens units in each metalens unit group, wherein the deflection angles of at least two metalens units in each metalens unit group are different, and at least two focal points of at least two metalens units are combined to form a lens focal point of the lens assembly;

[0012] According to the deflection angles of at least two meta-lens units in each meta-lens unit group, at least two meta-lens units are arranged on the substrate layer to obtain a lens assembly.

[0013] In a fifth aspect, an embodiment of the present application provides an electronic device, including:

[0014] A processor and a memory, the memory stores programs or instructions that can be run on the processor, and when the programs or instructions are executed by the processor, the steps of the design method in the fourth aspect are implemented.

[0015] In a sixth aspect, an embodiment of the present application provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of the method in the fourth aspect are implemented.

[0016] In the seventh aspect, an embodiment of the present application provides a chip, which includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method of the fourth aspect.

[0017] In an eighth aspect, an embodiment of the present application provides a computer program product, which is stored in a storage medium and is executed by at least one processor to implement the method of the fourth aspect.

[0018] In an embodiment of the present application, by adjusting the deflection angle of the meta-lens unit, different degrees of phase modulation can be generated on the incident circularly polarized light. The phase modulation degree is equal to twice the deflection angle of the meta-lens unit, and the meta-lens unit can be rotated from 0 degrees to 180 degrees, so the phase modulation of 0 degrees to 360 degrees is achieved. Through precise calculation, the deflection angles of different meta-lens units can be controlled. The meta-lens unit can be rotated by a certain angle. According to the principle of geometric phase, when the meta-lens unit rotates by an angle θ, a phase modulation of 2θ will be applied to the incident circularly polarized light. Therefore, by controlling the deflection angles of different meta-lens units, the focusing effect can be achieved.

[0019] In this embodiment, when the meta-lens unit is deflected by a certain angle, the focus of the meta-lens unit will also change. When designing the deflection angle of at least two meta-lens units, it is necessary to ensure that the focus of at least two meta-lens units can be fused into one focus. By adopting the multi-focal point fusion method, a focus with a large focal depth can be obtained, and this large focus will have a larger focal depth relative to the focus of the lens in the related art. This embodiment adopts the multi-focal point fusion method to design a large focal depth meta-lens. Compared with the lens in the related art, the meta-lens can increase the focal depth by 30%, thereby ensuring the focusing accuracy of the telephoto lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A three-dimensional structural diagram of a substrate layer and a meta-lens unit provided in some embodiments of the present application is shown;

[0021] Figure 2 A three-dimensional structural diagram of a substrate layer and a meta-lens unit provided in some embodiments of the present application is shown;

[0022] Figure 3 A three-dimensional structural diagram of a substrate layer and a meta-lens unit provided in some embodiments of the present application is shown;

[0023] Figure 4 A three-dimensional structural diagram of a substrate layer and a meta-lens unit provided in some embodiments of the present application is shown;

[0024] Figure 5 A front view of a substrate layer and a meta-lens unit provided in some embodiments of the present application is shown;

[0025] Figure 6 A left view of a substrate layer and a meta-lens unit provided in some embodiments of the present application is shown;

[0026] Figure 7 A top view of a substrate layer and a meta-lens unit provided by some embodiments of the present application is shown;

[0027] Figure 8 A schematic diagram showing the distribution of at least eight meta-lens unit groups provided in some embodiments of the present application is shown;

[0028] Fig. 9 A curve diagram showing the variation of the electric field intensity of the lens assembly provided by some embodiments of the present application in the Z direction;

[0029] Fig.10 A schematic diagram showing the distribution of four meta-lens unit groups provided in some embodiments of the present application is shown;

[0030] Fig.11 A schematic diagram showing the array distribution of sixty-four positions of meta-lens units provided in some embodiments of the present application is shown;

[0031] Fig.12 A schematic diagram showing the deflection angles of sixty-four meta-lens units provided in some embodiments of the present application;

[0032] Fig.13 A curve diagram showing the variation of the electric field intensity of the lens assembly provided by some embodiments of the present application in the Z direction;

[0033] Fig.14 A schematic diagram showing three focal points provided by some embodiments of the present application merged into one focal point with a large focal depth;

[0034] Fig.15 A top view of a lens assembly provided by some embodiments of the present application is shown;

[0035] Fig.16 A schematic diagram showing the focusing of a lens assembly in the X direction and the Z direction in the related art is shown;

[0036] Fig.17 Schematic diagrams showing the focusing of the lens assembly in the X direction and the Z direction provided by some embodiments of the present application;

[0037] Fig.18 A curve diagram showing the change of the electric field intensity of the lens assembly with the direction of the optical axis in the related art;

[0038] Fig.19 A curve diagram showing the electric field intensity of the lens assembly in the present application changing with the direction of the optical axis;

[0039] Fig. 20 A schematic diagram of a camera module provided in some embodiments of the present application is shown;

[0040] Fig.21 A flow chart showing a method for designing a lens assembly provided by some embodiments of the present application is shown;

[0041] Fig. 22 A schematic block diagram showing a design device for a lens assembly provided in some embodiments of the present application is shown;

[0042] Fig.23 A schematic block diagram of an electronic device provided by some embodiments of the present application is shown;

[0043] Fig.24 A schematic block diagram of an electronic device provided by some embodiments of the present application is shown.

[0044] Description of reference numerals:

[0045] 100-lens assembly, 110-base layer, 120-metastructure lens unit, 130-metastructure lens unit group, 200-camera module. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0047] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0048] The following is combined with Figures 1 to 24 , the lens assembly and its design method, camera module and electronic device provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0049] Combination Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, in some embodiments of the present application, a lens assembly 100 is provided, comprising: a base layer 110 and at least eight meta-lens unit groups arranged in an array, the meta-lens unit group 130 is disposed on the base layer 110, the meta-lens unit group 130 includes at least two meta-lens units 120, and the deflection angles of at least two meta-lens units 120 in a meta-lens unit group 130 are different, so that the at least two meta-lens units 120 are focused at different focal points, and at least two focal points of the at least two meta-lens units 120 are merged to form the lens focus of the lens assembly.

[0050] At least eight meta-lens unit groups 130 are arranged on the base layer 110. The lens assembly 100 in this embodiment can be a meta-lens. The meta-lens unit 120 in the meta-lens is usually designed manually, so a lens assembly 100 can be designed and manufactured according to one's own needs.

[0051] In this embodiment, in any meta-lens unit group 130, the deflection angles of at least two meta-lens units 120 are different, that is, at least two meta-lens units 120 are different from each other in the first direction ( Figure 7 The arrow points to (at A in the figure) with different deflection angles α.

[0052] By adjusting the deflection angle of the meta-lens unit 120, different degrees of phase modulation can be generated on the incident circularly polarized light. The phase modulation degree is equal to twice the deflection angle of the meta-lens unit 120, and the meta-lens unit 120 can rotate from 0 degrees to 180 degrees, so the phase modulation of 0 degrees to 360 degrees is achieved. Through precise calculation, the deflection angles of different meta-lens units 120 can be controlled. The meta-lens unit 120 can rotate a certain angle. According to the principle of geometric phase, when the meta-lens unit 120 rotates by an angle θ, a phase modulation of 2θ is applied to the incident circularly polarized light. Therefore, by controlling the deflection angles of different meta-lens units 120, the focusing effect can be achieved.

[0053] In this embodiment, when the meta-lens unit 120 is deflected by a certain angle, the focus of the meta-lens unit 120 will also change. When designing the deflection angle of at least two meta-lens units 120, it is necessary to ensure that the focus of at least two meta-lens units 120 can be fused into one focus. The fused focus is the lens focus of the lens assembly. When producing the lens assembly 100, it is necessary to determine the focus of the lens assembly 100. The focus of the lens assembly 100 is the above-mentioned lens focus. By adopting the multi-focus fusion method, a focus with a large focal depth can be obtained, such as Fig.14 As shown, the focus L, the focus M and the focus N are merged into a large focus, and the large focus has a large focal depth. This embodiment adopts a multi-focus fusion method to design a large focal depth meta-lens. Compared with a conventional lens, the meta-lens can increase the focal depth by 30%. The longer the focal depth, the less likely the object is to exceed the focus range. Therefore, by providing a large focal depth meta-lens, the focusing accuracy of the telephoto lens can be guaranteed.

[0054] For example, the base layer 110 can be made of a material with high transmittance and low refractive index, such as silicon dioxide, and the thickness of the base layer 110 is greater than the wavelength of the incident light. The meta-lens unit 120 can be a semiconductor nano-column, including a material with low loss in the visible light band, such as silicon nitride, titanium dioxide, and amorphous silicon, and the structural period of the meta-lens unit 120 is less than the wavelength of the incident light. Of course, in other embodiments, the composition of the base layer 110 and the meta-lens unit 120 is not limited to the materials mentioned above.

[0055] In some embodiments of the present application, optionally, under the action of electric field coupling, at least two focal points of at least two meta-lens units 120 are connected to form a lens focus.

[0056] Each meta-lens unit 120 has its own focus, and multiple foci need to be merged into a large focus. In this embodiment, the principle of electric field coupling is fully utilized so that the foci of at least two meta-lens units 120 can be merged, so that the lens assembly can obtain a focus with a large focal depth, thereby ensuring the focusing accuracy of the telephoto lens.

[0057] In some embodiments of the present application, optionally, when the position of the meta-lens unit 120 on the base layer 110 is different, the deflection angle of the meta-lens unit 120 may also be different.

[0058] Different deflection angles may be set for the meta-lens units 120 at different positions. After the deflection angle of the meta-lens unit 120 is determined according to the position of the meta-lens unit 120 , the lens assembly 100 may be manufactured by photolithography.

[0059] The amount of phase modulation that the meta-lens units 120 at different positions need to provide to the incident light may be different. Therefore, the deflection angle is determined according to the position of the meta-lens unit 120 to meet the phase modulation requirement. In this case, it is beneficial to achieve the focusing effect of the lens assembly 100, thereby improving the shooting clarity.

[0060] In some embodiments of the present application, optionally, among at least eight meta-lens units 130, a first array formed by at least eight meta-lens units 120 located at a first position is focused at a first focal length, and a second array formed by at least eight meta-lens units 120 located at a second position is focused at a lens focal length of the lens assembly 100; wherein the first focal length is greater than or less than the lens focal length.

[0061] The meta-lens units 120 at different positions need to provide different amounts of phase modulation to the incident light. Therefore, the deflection angle of the meta-lens unit 120 can be determined by controlling the above positions to achieve focusing.

[0062] A meta-lens unit group 130 includes M meta-lens units 120, and different meta-lens units 120 in a meta-lens unit group 130 are located at different positions, wherein in any meta-lens unit group 130, the meta-lens units 120 located at the first position and the second position are focused at the first focal length and the lens focal length, respectively.

[0063] The focal length of the lens assembly 100 is the lens focal length, and the focus of the lens focal length is the lens focus mentioned in the above embodiment. In a meta-lens unit group 130, by deflecting the meta-lens unit 120, the focal length of a part of the meta-lens unit 120 is the first focal length, and the focal length of a part of the meta-lens unit 120 is the lens focal length, and in the optical axis direction, the focus of the first focal length is located in front of or behind the focus of the target focal length.

[0064] Under the action of electric field coupling, the first focal length and the target focal length will be combined into a focus with a large focal depth, and this large focal length has a larger focal depth than the focus of the lens in the related art. Applying this large focal depth lens to the telephoto of electronic equipment can improve the focusing accuracy of the telephoto lens.

[0065] The meta-lens in this embodiment has a greater focal depth, which is 30% longer than a conventional lens, achieving a high focusing accuracy of a large-bottom telephoto module lens. Moreover, the meta-lens with a large focal depth in this embodiment is much smaller than the lens on current mobile phones, and has a higher degree of integration, which can optimize the internal space of the mobile phone. At the same time, the meta-lens in this embodiment does not need to be designed as a circle according to the use requirements, for example, it can be designed as a rectangle, which is easier to use in a periscope telephoto module.

[0066] The lens assembly 100 includes at least eight meta-lens unit groups 130, and each meta-lens unit group 130 performs focal fusion in the above-mentioned manner, that is, the array formed by the meta-lens units 120 located at the first position in the at least eight meta-lens unit groups 130 is the first array, and each meta-lens unit 120 located in the first array is focused at the first focal length. The array formed by the meta-lens units 120 located at the second position in the at least eight meta-lens unit groups 130 is the second array, and each meta-lens unit 120 in the second array is focused at the lens focal length. In the above-mentioned manner, the at least eight meta-lens unit groups 130 are regularly designed, which can simplify the design difficulty of the lens assembly 100.

[0067] Combination Figure 7 and Figure 8 As shown, in some embodiments of the present application, optionally, in each meta-lens unit group 130, the first deflection angle θ1 of the first array is obtained by the formula Calculated, where F1 is the first focal length, and in the first array, θ1 is the deflection angle of the meta-lens unit 120 at the (x, y) position.

[0068] The second deflection angle θ of the second array is given by the formula Calculated, where F is the focal length of the lens, in the second array, θ is the deflection angle of the meta-lens unit 120 at the (x, y) position; where λ is the wavelength of the incident electromagnetic wave, and (x, y) is the position of the meta-lens unit 120.

[0069] A meta-lens unit group 130 including two meta-lens units 120 is used for exemplary description. The two meta-lenses are arranged side by side or in parallel, wherein the meta-lens unit 120 on the left is located at the first position, and the meta-lens unit 120 on the right is located at the first position.

[0070] The meta-lens unit 120 on the left is rotated by an angle θ1 based on the focal length F1, and θ1 is calculated by the following formula (1):

[0071]

[0072] The meta-lens unit 120 on the right side is rotated by an angle θ based on the focal length F, where θ is calculated by the following formula (2):

[0073]

[0074] Wherein, λ is the wavelength of the incident electromagnetic wave, and in formulas (1) and (2), (x, y) is the position of the meta-lens unit 120.

[0075] Then, the two-in-one meta-lens unit group 130 is arrayed to form a complete lens assembly 100, in which the left meta-lens unit 120 in each two-in-one meta-lens unit group 130 rotates at an angle θ1 to achieve focusing of focal length F1, where θ1 is calculated by formula (1). The right meta-lens unit 120 in each meta-lens unit group 130 rotates at an angle θ to achieve focusing of focal length F, where θ is calculated by formula (2).

[0076] Therefore, the entire lens assembly 100 can achieve focusing of two focal points, and these two focal points will be merged into a focus with a large focal depth under the action of electric field coupling, and this large focus will have a larger focal depth than the focus of the lens in the related art.

[0077] Fig. 9 In the graph, curve b1 is a graph of the electric field strength of the meta-lens unit 120 at the first position as it changes in the Z direction, where the Z direction refers to the optical axis direction of the lens assembly 100. Curve b2 is a graph of the electric field strength of the meta-lens unit 120 at the second position as it changes in the Z direction, and curve b3 is a graph of the electric field strength of the lens assembly 100 as it changes in the Z direction. The curve b1 and the curve b2 are combined to obtain the curve b3. Of course, Fig. 9 This is only to facilitate understanding of the solution in this embodiment. In actual production, the change in electric field strength still needs to be based on the simulation results.

[0078] Combination Figure 1 , Figure 7 , Fig.10 and Fig.11As shown, in some embodiments of the present application, optionally, in at least eight meta-lens unit groups 130, a first array formed by at least eight meta-lens units 120 located at a first position is focused at a first focal length, a second array formed by at least sixteen meta-lens units 120 located at a second position and a third position is focused at a lens focal length of the lens assembly, and a third array formed by at least eight meta-lens units 120 located at a fourth position is focused at a second focal length; wherein the first focal length is greater than the lens focal length, and the second focal length is less than the lens focal length.

[0079] The meta-lens units 120 at different positions need to provide different amounts of phase modulation to the incident light. Therefore, the deflection angle of the meta-lens unit 120 can be determined by controlling the above positions to achieve focusing.

[0080] A meta-lens unit group 130 includes at least two meta-lens units 120, and different meta-lens units 120 in a meta-lens unit group 130 are located at different positions, wherein in any meta-lens unit group 130, the meta-lens unit 120 located at a first position is focused at a first focal length, the meta-lens unit 120 located at a second position is focused at a target focal length, and the meta-lens unit 120 located at a third position is focused at a second focal length.

[0081] The focal length of the lens assembly 100 is the lens focal length, and the focus of the lens focal length is the lens focus mentioned in the above embodiment. In a meta-lens unit group 130, by deflecting the meta-lens unit 120, the focal length of a part of the meta-lens unit 120 is the target focal length, the focal length of a part of the meta-lens unit 120 is the first focal length greater than the target focal length, and the focal length of another part of the meta-lens unit 120 is the second focal length less than the target focal length, and the focal points of the first focal length and the second focal length are located in front of and behind the focus of the target focal length.

[0082] Under the action of electric field coupling, the first focal length, the target focal length and the second focal length will be combined into a focal point with a large focal depth, and this large focal point has a larger focal depth than the focal point of the lens in the related art. Two small focal points are formed before and after the focal point of the core focal length. These three focal points together can realize a focal point with a large focal depth. Applying this large focal depth lens to the telephoto of electronic equipment can improve the focusing accuracy of the telephoto lens.

[0083] The meta-lens in this embodiment has a greater focal depth, which is 30% longer than that of a conventional lens, achieving a more accurate focusing effect of a large-bottom telephoto module lens. Moreover, the meta-lens with a large focal depth in this embodiment is much smaller than the lens on current mobile phones, and has a higher degree of integration, which can optimize the internal space of the mobile phone. At the same time, the meta-lens in this embodiment does not need to be designed as a circle according to the use requirements, for example, it can be designed as a rectangle, which is easier to use in a periscope telephoto module.

[0084] The lens assembly 100 includes at least eight meta-lens unit groups 130, and each meta-lens unit group 130 performs focus fusion in the above-mentioned manner, that is, the array formed by the meta-lens units 120 located at the first position in the at least eight meta-lens unit groups 130 is the first array, and each meta-lens unit 120 located in the first array is focused at the first focal length. The array formed by the meta-lens units 120 located at the second position and the third position in the at least eight meta-lens unit groups 130 is the second array, and each meta-lens unit 120 located in the second array is focused at the lens focal length. The array formed by the meta-lens units 120 located at the fourth position in the at least eight meta-lens unit groups 130 is the third array, and each meta-lens unit 120 in the third array is focused at the second focal length. In the above-mentioned manner, the design difficulty of the lens assembly 100 can be simplified by regularly designing at least eight meta-lens unit groups 130.

[0085] Combination Fig.10 and Fig.11 As shown, in some embodiments of the present application, optionally, in each meta-lens unit group 130, the first deflection angle θ1 of the first array is calculated by the following formula (3), wherein F1 is the first focal length, and in the first array, θ1 is the deflection angle of the meta-lens unit 120 at the (x, y) position.

[0086]

[0087] The second deflection angle θ of the second array is calculated by the following formula (4), where F is the focal length of the lens, and in the second array, θ is the deflection angle of the meta-lens unit 120 at the (x, y) position.

[0088]

[0089] The third deflection angle θ2 of the third array is calculated by the following formula (5), where F2 is the second focal length, and in the third array, θ2 is the deflection angle of the meta-lens unit 120 at the (x, y) position.

[0090]

[0091] Wherein, λ is the wavelength of the incident electromagnetic wave, and in formulas (3), (4) and (5), (x, y) is the position of the meta-lens unit 120.

[0092] The essence of focusing is to make the phase distribution of the incident light wave after passing through the device calculated by formula (6):

[0093]

[0094] In the formula, represents the phase modulation amount, λ is the wavelength of the incident electromagnetic wave, is the distance between the lens assembly 100 and the center of the metasurface, (x, y) is the coordinate point of the metalens unit 120 in the plane coordinate system established with the center of the lens assembly 100 as the origin, and F is the focal length of the metasurface to achieve focusing. According to this formula, the amount of phase modulation that the metalens unit 120 at different (x, y) positions needs to provide to the incident light can be determined, so focusing can be achieved by controlling the rotation angle of the metalens unit 120 at that position.

[0095] Exemplarily, a meta-lens unit group 130 includes four meta-lens units 120 for exemplary description, and the four meta-lenses are distributed in 2 columns and 2 rows, wherein the meta-lens unit 120 in the upper left corner is located at the first position, the meta-lens units 120 in the upper right corner and the lower left corner are located at the second position, and the meta-lens unit 120 in the lower right corner is located at the third position.

[0096] The meta-lens unit 120 at the upper left corner rotates at an angle θ1 to achieve focusing of focal length F1, where θ1 is calculated by formula (3). The meta-lens units 120 at the upper right corner and the lower left corner rotate at an angle θ to achieve focusing of focal length F, where θ is calculated by formula (4). The meta-lens unit 120 at the lower right corner rotates at an angle θ2 to achieve focusing of focal length F2, where θ2 is calculated by formula (5). The four-in-one meta-lens unit group 130 is then arrayed to form a complete lens assembly 100.

[0097] For the purpose of exemplary description, this embodiment Fig.11An 8×8 lens assembly 100 is drawn in FIG. 1 , however, for the lens assembly 100 actually produced, the number of meta-lens units 120 is not limited to sixty-four. In this embodiment, the meta-lens assembly a has sixty-four meta-lens units 120, and the rotation angle of the meta-lens unit 120 in the upper left corner of each four-in-one meta-lens unit group 130 is calculated by formula (3), that is, the rotation angle of the sixteen meta-lens units 120 in the first array b is calculated by formula (3), so this partial structure can achieve focusing of the focal length F1. The rotation angles of the meta-lens units 120 in the upper right corner and the lower left corner of each meta-lens unit group 130 are calculated by formula (4), and the rotation angles of the thirty-two meta-lens units 120 in the second array c are calculated by formula (4). Therefore, this partial structure can achieve focusing of the focal length F. The rotation angle of the meta-lens unit 120 at the lower right corner of each four-in-one meta-lens unit group 130 is calculated by formula (5), that is, the rotation angle of the sixteen meta-lens units 120 in the third array d is calculated by formula (5), so this partial structure can achieve focusing of the focal length F2. Fig.12 An 8×8 lens assembly 100 is shown in FIG. Fig.12 (f) shows the rotation angle of the upper left corner meta-lens unit 120 in each four-in-one meta-lens unit group 130, that is, the rotation angle of the meta-lens unit 120 in the first array b. Fig.12 (g) shows the rotation angles of the meta-lens units 120 at the upper right corner and the lower left corner in each four-in-one meta-lens unit group 130, that is, the rotation angles of the meta-lens units 120 in the second array c. Fig.12 (h) shows the rotation angle of the meta-lens unit 120 at the lower right corner of each four-in-one meta-lens unit group 130, that is, the rotation angle of the meta-lens unit 120 in the third array d. Fig.12 (e) shows the set of rotation angles of the meta-lens units 120 located at the upper left corner, upper right corner, lower left corner, and lower right corner in each four-in-one meta-lens unit group 130, that is, the rotation angles of all meta-lens units 120 in the meta-lens assembly a.

[0098] Therefore, the entire lens assembly 100 can achieve three focal points. When the three focal points are close to each other, they will be merged into a focal point with a large focal depth. This large focal point will have a larger focal depth than the focal point of the lens in the related art.

[0099] Fig.14 In the figure, focus M is the focus of the lens focal length, focus L is the focus of the first focal length, and focus N is the focus of the second focal length.

[0100] Fig.13 In the figure, curve c1 is a graph of the electric field strength of the meta-lens unit 120 at the first position as it changes in the Z direction. Curve c2 is a graph of the electric field strength of the meta-lens unit 120 at the second and third positions as it changes in the Z direction. Curve c3 is a graph of the electric field strength of the meta-lens unit 120 at the fourth position as it changes in the Z direction. Curve c4 is a graph of the electric field strength of the lens assembly 100 as it changes in the Z direction. Curve c1, curve c2, and curve c3 are combined to obtain curve c4. Of course, Fig.13 This is only to facilitate understanding of the solution in this embodiment. In actual production, the change in electric field strength still needs to be based on the simulation results.

[0101] like Fig.15 As shown, the schematic diagram of the meta-lens designed for green light with a wavelength of 532nm. Fig.15 is a top view of the lens assembly. Fig.15 As can be seen from the figure, the rotation angle of each meta-lens unit 120 is different, and its rotation angle is exactly in accordance with the Fig.11 The three focal points shown are focused and rotated with a specially designed angular distribution.

[0102] Fig.16 and Fig.17 The focusing diagram of the meta-lens in the related art and the large focal depth meta-lens designed in this embodiment is compared. The meta-lens in the related art is designed according to the core focal length F, without considering the front focal length F1 and the back focal length F2. Both are designed according to the core focal length F equal to 5.5 microns. It should be noted that the simulation design in this embodiment is based on the lens diameter of the lens assembly 100 being 10μm. In the large focal depth meta-lens, F1 is 5 microns and F2 is 6 microns. Combined Fig.16 and Fig.17 It can be seen intuitively that Fig.16 The focal depth of the super lens is 1.04μm. Fig.17 The focal depth of the super lens is 1.35μm. Fig.17 The focal depth to length ratio of the super lens Fig.16 The focal depth of the medium meta-lens is 0.31 μm, and the focal depth of the large focal depth meta-lens is greater than that of the meta-lens in the related art.

[0103] Fig.18 and Fig.19 A more intuitive comparison of the focal depths of the two meta-lenses is given. Fig.18 is the focal depth of the meta-lens in the related art, Fig.19is the focal depth length of the large focal depth meta-lens. The focal depth length is generally defined as the length when the energy intensity at the focus drops to half of the peak intensity. It can be seen that the focal depth length of the meta-lens in the related art is 1.04μm, while the focal depth length of the large focal depth meta-lens is 1.35μm. Compared with the meta-lens in the related art, the focal depth length of the meta-lens in this embodiment is increased by about 30%. At the same time, simulation calculations show that the transmittance of the meta-lens designed in this embodiment is greater than 80%, which is greater than the existing large focal depth meta-lens, and gradually approaches the transmittance of the lens currently used on mobile phones.

[0104] In some embodiments of the present application, optionally, the distance between the first focal length and the lens focal length is less than or equal to a distance threshold, and the distance between the second focal length and the lens focal length is less than or equal to a distance threshold.

[0105] Along the optical axis of the lens assembly ( Fig.14 The arrow at the bottom of the middle substrate layer 110 indicates the incident direction of the light, which can also be used as the optical axis direction). The position corresponding to the maximum electric field intensity of the lens assembly is the fifth position, and the position corresponding to the electric field intensity of half the maximum electric field intensity is the sixth position. The distance between the fifth position and the sixth position is equal to the distance threshold.

[0106] Under the action of electric field coupling, multiple foci can be merged into a large focus. In order to merge multiple foci, it is necessary to ensure that the distance between adjacent foci meets a certain range. If the distance between adjacent foci is too large, the adjacent foci cannot be merged under the action of electric field coupling.

[0107] The electric field strength of the lens assembly at different positions in the optical axis direction is different, wherein the position where the electric field strength of the lens assembly is the largest is set as the fifth position, and the fifth position is usually the position of the lens focus. The position where the electric field strength is half of the maximum electric field strength is the sixth position, and the distance between the fifth position and the sixth position is the distance threshold. The distance between any two adjacent focal positions is less than or equal to the distance threshold. When the above conditions are met, it can be ensured that multiple focal points can be merged into a large focal point under the action of electric field coupling.

[0108] In some embodiments of the present application, optionally, when the meta-lens unit 120 is cut, the cross-sectional shape of the meta-lens unit 120 includes: a rectangle, a circle, or an ellipse. The width direction of the meta-lens unit 120 is Figure 6 The arrow at W in the middle points to.

[0109] According to the working wavelength of the lens assembly 100, the size parameters of the meta-lens unit 120 can be determined, including the period length, the width and the height of the meta-lens unit 120, so that the circularly polarized light of the desired working wavelength can produce a high polarization conversion rate after passing through the meta-lens unit 120.

[0110] The cross section of the metalens unit 120 in this embodiment is elliptical, with a height of generally 500nm to 1000nm, a major radius of generally 100nm to 300nm, and a minor radius of generally 5nm to 15nm. Of course, in other embodiments, the cross section of the metalens unit 120 can also be rectangular, polygonal, or cross-shaped.

[0111] The meta-lens has the advantage of being small in thickness. By designing the shape of the meta-lens unit 120 according to the requirements, the meta-lens unit 120 can be made to better fit the layout space inside the camera module 200 .

[0112] This application adopts a multi-focus fusion method to design a large focal depth meta-lens that can be used in a large-base telephoto module. It has a small size, high integration, and a large focal depth, which can improve the focusing accuracy of the telephoto lens. At the same time, the meta-lens can be made into a square shape, which is more convenient for use in periscope telephoto modules.

[0113] In an embodiment of the present application, a camera module 200 is proposed, which includes a lens assembly 100 as in any of the above embodiments and can achieve the same technical effects, which will not be described in detail herein.

[0114] In a possible embodiment, the camera module 200 generally includes a plurality of lenses, and a lens located at the end is the lens assembly 100 in this embodiment.

[0115] Generally, the first lens in the camera module 200 is a convex lens, that is, a lens for achieving focusing. The meta-lens designed and manufactured in this application replaces the convex lens in the conventional lens module to form a new lens, such as Fig. 20 At this time, the lens assembly 100 can achieve focusing with a large focal depth. At the same time, since the thickness of the lens assembly 100 is only a few microns, which is much smaller than the thickness of a traditional convex lens, it is beneficial to further reduce the thickness of the lens module, improve the integration of the lens module, and facilitate the thinness of the mobile phone.

[0116] In an embodiment of the present application, an electronic device is proposed, including a camera module as in the above embodiment, and can achieve the same technical effect, which will not be repeated here.

[0117] Exemplarily, the electronic device may be a mobile phone, a tablet computer, a smart wearable device, etc.

[0118] In some embodiments of the present application, a design method of a lens assembly is provided, which is applied to the lens assembly in any of the above embodiments. Fig.21 Schematic diagram of the design method provided in some embodiments of the present application is shown. Fig.21 As shown, the design method includes:

[0119] Step 402, obtaining the deflection angles of at least two metalens units in each metalens unit group, wherein the deflection angles of at least two metalens units in each metalens unit group are different, and at least two focal points of at least two metalens units are combined to form a lens focus of the lens assembly;

[0120] Step 404: according to the deflection angles of at least two meta-lens units in each meta-lens unit group, at least two meta-lens units are arranged on the base layer to obtain a lens assembly.

[0121] In an embodiment of the present application, by adjusting the deflection angle of the meta-lens unit, different degrees of phase modulation can be generated on the incident circularly polarized light. The phase modulation degree is equal to twice the deflection angle of the meta-lens unit, and the meta-lens unit can be rotated from 0 degrees to 180 degrees, so the phase modulation of 0 degrees to 360 degrees is achieved. Through precise calculation, the deflection angles of different meta-lens units can be controlled. The meta-lens unit can be rotated by a certain angle. According to the principle of geometric phase, when the meta-lens unit rotates by an angle θ, a phase modulation of 2θ will be applied to the incident circularly polarized light. Therefore, by controlling the deflection angles of different meta-lens units, the focusing effect can be achieved.

[0122] In this embodiment, when the meta-lens unit is deflected by a certain angle, the focus of the meta-lens unit will also change. When designing the deflection angle of at least two meta-lens units, it is necessary to ensure that the focus of at least two meta-lens units can be fused into one focus. The fused focus is the lens focus of the lens assembly. When producing the lens assembly, it is necessary to determine the focus of the lens assembly, and the focus of the lens assembly is the above-mentioned lens focus. By adopting the multi-focal point fusion method, a focus with a large focal depth can be obtained, and this large focus will have a larger focal depth relative to the focus of the lens in the related art. This embodiment adopts the multi-focal point fusion method to design a large focal depth meta-lens. Compared with the lens in the related art, the meta-lens can increase the focal depth by 30%, thereby ensuring the accuracy of the focus of the telephoto lens, ensuring the accurate focus of the lens module and clear images.

[0123] For example, the base layer can be made of a material with high transmittance and low refractive index such as silicon dioxide, the thickness of the base layer is greater than the wavelength of the incident light, the meta-lens unit can be a semiconductor nano-column, including silicon nitride, titanium dioxide, amorphous silicon and other materials with low loss in the visible light band, and the structural period of the meta-lens unit is less than the wavelength of the incident light. Of course, in other embodiments, the composition of the base layer and the meta-lens unit is not limited to the materials mentioned above.

[0124] In one possible application, the dimensional parameters of the meta-lens unit, including the period length, the width and the height of the meta-lens unit, can be determined according to the operating wavelength of the lens assembly, so that circularly polarized light of the operating wavelength can produce a high polarization conversion rate after passing through the meta-lens unit.

[0125] The design method provided in the embodiment of the present application can be executed by a design device. In the embodiment of the present application, the design method provided in the embodiment of the present application is described by taking the design device executing the design method as an example.

[0126] In some embodiments of the present application, a design device is provided, which is applied to the lens assembly in any of the above embodiments. Fig. 22 FIG. 1 is a schematic block diagram of a design device provided in some embodiments of the present application. Fig. 22 As shown, the design device 500 includes:

[0127] An acquisition module 510 is provided for acquiring the deflection angles of at least two meta-lens units in each meta-lens unit group, wherein the deflection angles of at least two meta-lens units in each meta-lens unit group are different, and at least two focal points of at least two meta-lens units are combined to form a lens focal point of the lens assembly;

[0128] The design module 520 arranges at least two meta-lens units on the base layer according to the deflection angles of at least two meta-lens units in each meta-lens unit group to obtain a lens assembly.

[0129] In the embodiment of the present application, when the meta-lens unit is deflected at a certain angle, the focus of the meta-lens unit will also change. When designing the deflection angle of the meta-lens unit, it is necessary to ensure that the focus of multiple meta-lens units can be fused into one focus. By adopting the multi-focal point fusion method, a focus with a large focal depth can be obtained, and this large focus will have a larger focal depth relative to the focus of the lens in the related art. This embodiment adopts the multi-focal point fusion method to design a large focal depth meta-lens. Compared with the lens in the related art, the meta-lens can increase the focal depth by 30%, thereby ensuring the accuracy of the focus of the telephoto lens, ensuring the accurate focus of the lens module and clear images.

[0130] The design device in the embodiment of the present application can be an electronic device, or a component in the electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal, or other devices other than a terminal. Exemplarily, the electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, a vehicle-mounted electronic device, a mobile Internet device (Mobile Internet Device, MID), an augmented reality (augmented reality, AR) / virtual reality (virtual reality, VR) device, a robot, a wearable device, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a netbook or a personal digital assistant (personal digital assistant, PDA), etc., and can also be a server, a network attached storage (Network Attached Storage, NAS), a personal computer (personal computer, PC), a television (television, TV), a teller machine or a self-service machine, etc., which is not specifically limited in the embodiment of the present application.

[0131] The design device in the embodiment of the present application may be a device having an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0132] The design device provided in the embodiment of the present application can implement each process implemented in the above method embodiment. To avoid repetition, it will not be described here.

[0133] Optionally, an embodiment of the present application further provides an electronic device, which includes a design device as in any of the above embodiments, and thus has all the beneficial effects of the design method in any of the embodiments, which will not be elaborated herein.

[0134] Optionally, an embodiment of the present application further provides an electronic device, Fig.23 A structural block diagram of an electronic device according to an embodiment of the present application is shown. Fig.23 As shown, the electronic device 600 includes a processor 602, a memory 604, and a program or instruction stored in the memory 604 and executable on the processor 602. When the program or instruction is executed by the processor 602, each process of the above-mentioned design method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0135] It should be noted that the electronic devices in the embodiments of the present application include the above-mentioned mobile electronic devices and non-mobile electronic devices.

[0136] Fig.24 A schematic diagram of the hardware structure of an electronic device to implement an embodiment of the present application.

[0137] The electronic device 700 includes but is not limited to: a radio frequency unit 701, a network module 702, an audio output unit 703, an input unit 704, a sensor 705, a display unit 706, a user input unit 707, an interface unit 708, a memory 709, a processor 710, a camera 711 and other components, wherein the camera 711 includes a base layer 110 and a meta-lens unit 120.

[0138] Those skilled in the art will appreciate that the electronic device 700 may also include a power source (such as a battery) for supplying power to each component, and the power source may be logically connected to the processor 710 through a power management system, thereby implementing functions such as managing charging, discharging, and power consumption management through the power management system. Fig.24 The electronic device structure shown in the figure does not constitute a limitation on the electronic device. The electronic device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently, which will not be described in detail here.

[0139] Among them, the processor 710 obtains the deflection angle of at least two meta-lens units in each meta-lens unit group, the deflection angles of at least two meta-lens units in each meta-lens unit group are different, and at least two focal points of at least two meta-lens units are combined to form the lens focus of the lens assembly; according to the deflection angle of at least two meta-lens units in each meta-lens unit group, at least two meta-lens units are arranged on the base layer to obtain a lens assembly.

[0140] In an embodiment of the present application, a large focal depth meta-lens is designed by a multi-focus fusion method. Compared with the lens in the related art, the focal depth of the meta-lens can be increased by 30%, thereby ensuring the focusing accuracy of the telephoto lens, ensuring the accurate focusing of the lens module and clear images.

[0141] It should be understood that in the embodiment of the present application, the input unit 704 may include a graphics processor (Graphics Processing Unit, GPU) 7041 and a microphone 7042, and the graphics processor 7041 processes the image data of the static picture or action file obtained by the image capture device (such as a camera) in the action file capture mode or the image capture mode. The display unit 706 may include a display panel 7061, and the display panel 7061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 707 includes a touch panel 7071 and at least one of other input devices 7072. The touch panel 7071 is also called a touch screen. The touch panel 7071 may include two parts: a touch detection device and a touch controller. Other input devices 7072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which will not be repeated here.

[0142] The memory 709 can be used to store software programs and various data. The memory 709 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data, wherein the first storage area may store an operating system, an application program or instructions required for at least one function (such as a sound playback function, an image playback function, etc.), etc. In addition, the memory 709 may include a volatile memory or a non-volatile memory, or the memory 709 may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDRSDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchronous link dynamic random access memory (SLDRAM) and a direct memory bus random access memory (DRRAM). The memory 709 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0143] The processor 710 may include one or more processing units; optionally, the processor 710 integrates an application processor and a modem processor, wherein the application processor mainly processes operations related to an operating system, a user interface, and application programs, and the modem processor mainly processes wireless communication signals, such as a baseband processor. It is understandable that the modem processor may not be integrated into the processor 710.

[0144] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0145] The processor is the processor in the electronic device in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0146] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned design method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0147] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0148] An embodiment of the present application provides a computer program product, which is stored in a storage medium. The program product is executed by at least one processor to implement the various processes of the above-mentioned design method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0149] It should be noted that, in this article, the term "comprises", "includes" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, device, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or device. In the absence of further restrictions, an element defined by the statement "includes one..." does not exclude the presence of other identical elements in the process, device, article or device including the element. In addition, it should be noted that the scope of the devices and apparatuses in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described device may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0150] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment device can be implemented by means of software plus a necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, disk, CD), including a number of instructions for a terminal (which can be a mobile phone, computer, server, or network equipment, etc.) to execute the device of each embodiment of the present application.

[0151] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A lens assembly, characterized in that: include: basal layer; At least eight meta-lens unit groups arranged in an array are disposed on the base layer, wherein the meta-lens unit groups include at least two meta-lens units, and at least two meta-lens units in one meta-lens unit group have different deflection angles, so that at least two of the meta-lens units are focused at different focal points, and at least two focal points of at least two of the meta-lens units are combined to form a lens focus of the lens assembly.

2. The lens assembly according to claim 1, characterized in that Under the action of electric field coupling, at least two focal points of at least the two meta-lens units are connected to form the lens focus.

3. The lens assembly according to claim 1 or 2, characterized in that: In the at least eight meta-lens units group, a first array formed by at least eight meta-lens units located at a first position is focused at a first focal length, and a second array formed by at least eight meta-lens units located at a second position is focused at a lens focal length of the lens assembly; Wherein, the first focal length is greater than or less than the lens focal length.

4. The lens assembly according to claim 3, characterized in that In each meta-lens unit group, the first deflection angle θ1 of the first array is given by the formula Calculated, wherein F1 is the first focal length, and in the first array, θ1 is the deflection angle of the meta-lens unit at the (x, y) position; The second deflection angle θ of the second array is given by the formula Calculated, where F is the focal length of the lens, and θ is the deflection angle of the metalens unit at the (x, y) position in the second array; Wherein, λ is the wavelength of the incident electromagnetic wave, and (x, y) is the position of the meta-lens unit.

5. The lens assembly according to claim 1 or 2, characterized in that: In the at least eight meta-lens units group, a first array formed by at least eight meta-lens units located at a first position is focused at a first focal length, a second array formed by at least sixteen meta-lens units located at a second position and a third position is focused at a lens focal length of the lens assembly, and a third array formed by at least eight meta-lens units located at a fourth position is focused at a second focal length; The first focal length is greater than the lens focal length, and the second focal length is less than the lens focal length.

6. The lens assembly according to claim 5, characterized in that In each meta-lens unit group, the first deflection angle θ1 of the first array is given by the formula Calculated, wherein F1 is the first focal length, and in the first array, θ1 is the deflection angle of the meta-lens unit at the (x, y) position; The second deflection angle θ of the second array is given by the formula Calculated, where F is the focal length of the lens, and θ is the deflection angle of the metalens unit at the (x, y) position in the second array; The third deflection angle θ2 of the third array is given by the formula Calculated, where F2 is the focal length of the lens, and in the third array, θ2 is the deflection angle of the meta-lens unit at the (x, y) position; Wherein, λ is the wavelength of the incident electromagnetic wave, and (x, y) is the position of the meta-lens unit.

7. The lens assembly according to claim 5, characterized in that The distance between the first focal length and the lens focal length is less than or equal to a distance threshold, and the distance between the second focal length and the lens focal length is less than or equal to a distance threshold; Along the optical axis direction of the lens assembly, the position corresponding to the maximum electric field strength of the lens assembly is the fifth position, the position corresponding to the electric field strength of half the maximum electric field strength is the sixth position, and the distance between the fifth position and the sixth position is equal to the distance threshold.

8. The lens assembly according to claim 1 or 2, characterized in that: The cross-sectional shape of the meta-lens unit along the width direction is rectangular, circular or elliptical.

9. A camera module, characterized in that: A lens assembly comprising the lens assembly of any one of claims 1 to 8.

10. An electronic device, characterized in that: Comprising the camera module as described in claim 9.

11. A method for designing a lens assembly, used for designing a lens assembly as claimed in any one of claims 1 to 8, characterized in that: The design method comprises: Obtaining the deflection angles of at least two metalens units in each metalens unit group, wherein the deflection angles of at least two metalens units in each metalens unit group are different, and at least two focal points of the at least two metalens units are combined to form a lens focus of the lens assembly; According to the deflection angles of at least two meta-lens units in each of the meta-lens unit groups, at least two meta-lens units are arranged on the substrate layer to obtain a lens assembly.

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