Fly-eye mother lens formed by liquid sub-lens array with adjustable focal length and preparation method of fly-eye mother lens

Abstract

The invention relates to the technical field of micro optics, in particular to a compound eye mother lens composed of a focal length-adjustable liquid sub-lens array and a preparation method, the compound eye mother lens comprises an outer skeleton, an inner skeleton, a transparent elastic film and a liquid storage container; the outer framework and the inner framework are correspondingly arranged in an arc shape, first through holes are formed in the outer framework along a center array, second through holes corresponding to the first through holes are formed in the inner framework, and the transparent elastic film is arranged between the inner framework and the outer framework to form a compound eye structure; the number of the compound eye structures is at least two, the liquid storage container is arranged between the compound eye structures, and a liquid injection hole is formed in the liquid storage container. Liquid in the liquid storage container is controlled through the liquid injection hole, so that a pressure difference is formed inside and outside the compound eye mother lens, the compound eye structure is driven to deform, the transparent elastic film is divided into a plurality of sub-lenses, the effect of an insect compound eye is achieved, a lens array is formed, then focal length adjustment is conducted, and the problem that the spherical aberration is large is solved.

Description

Technical Field

[0001] The present invention relates to the field of micro-optical technology, and particularly to a compound eye mother lens composed of a liquid sub-lens array with adjustable focal length and a preparation method thereof. Background Art

[0002] In micro-optical technology, a microlens array is an important optical element, which shows broad application prospects in the fields of optical communication, optical imaging, optical storage, etc. As a cutting-edge two-dimensional integrated optical component, the microlens array is indispensable for promoting the progress of micro-optical elements, waveguide devices and optical integration systems. Its precise array structure has brought revolutionary application potential to multiple fields such as optical communication, optical imaging, optical storage, optical display, and optical information processing. For example, efficient optical interconnection systems, complex image transformation and recognition technologies, and multifunctional optical passive device arrays created by microlens arrays have long attracted the close attention of the academic and industrial communities.

[0003] However, the focal length of the microlens array products widely used in the market today is fixed. Although it brings convenience in manufacturing and cost control, it also greatly limits the flexibility and application scope of optical devices. Due to the lack of the ability to adjust the focal length, the fixed-focal-length microlens array cannot dynamically adjust the focal length or cannot be adjusted according to the application scenarios of different working environments, resulting in a decline in the overall performance of the microlens array and a reduction in potential application fields. For example, in occasions where it is necessary to adjust the focal length in real time to adapt to imaging of objects at different distances, the fixed-focal-length microlens array cannot meet the requirements, restricting its use in some high-end applications. Moreover, due to the fixed focal length, the microlens array has a low duty cycle and large spherical aberration, affecting the imaging quality. Summary of the Invention

[0004] In order to solve the technical problems that the focal length of the existing microlens array products cannot be dynamically adjusted, the application scope is small, and the imaging quality is affected, the purpose of the present invention is to provide a compound eye mother lens composed of a liquid sub-lens array with adjustable focal length, and the specific technical solution adopted is as follows: An outer skeleton, an inner skeleton, a transparent elastic film and a liquid storage container; The outer skeleton and the inner skeleton are correspondingly arranged in an arc shape. The outer skeleton is provided with first through holes arrayed along the center, and the inner skeleton is provided with second through holes corresponding to the first through holes. The transparent elastic film is arranged between the inner skeleton and the outer skeleton to form a compound eye structure; At least two of the compound eye structures are included, the liquid storage container is arranged between the compound eye structures, and the liquid storage container is provided with a liquid injection hole.

[0005] Preferably, the shapes of the first through hole and the second through hole include any one of circular, square and hexagonal.

[0006] To solve the above problems, the present application also proposes: a preparation method of a compound eye mother lens with adjustable focal length, which is used to prepare a compound eye mother lens composed of a liquid sub-lens array with adjustable focal length as described in any one of the foregoing items. The method includes: Obtain an outer skeleton and an inner skeleton, and perform pre-treatment; Define the pre-treated inner skeleton as the base layer, cover a transparent elastic film and the pre-treated outer skeleton in sequence along the vertical direction, and fix to form a compound eye structure; A liquid storage container is arranged between the compound eye structures. Insert a thin hard tube based on the liquid injection hole and use ultraviolet light-curing glue to bond the gap for sealing; Connect a liquid pumping mechanism to the other end of the thin hard tube. Inject or extract liquid into the liquid storage container through the liquid pumping mechanism. The liquid storage container correspondingly forms a pressure difference to drive the compound eye structure to deform, driving the transparent elastic film to bulge or sink.

[0007] Preferably, obtaining an outer skeleton and an inner skeleton, and performing pre-treatment includes: Based on parametric modeling, open a first through hole and a second through hole on the outer skeleton and the inner skeleton respectively, and the first through hole corresponds to the second through hole, and adjust the curvature of the outer skeleton and the inner skeleton; Perform pre-treatment by cleaning with isopropyl alcohol, UV strengthening, and nano-hydrophobic coating.

[0008] Preferably, the materials of the outer skeleton and the inner skeleton are any one of PLA, ABS, flexible TPU, PA, titanium alloy, stainless steel, carbon fiber composite material, and silicone rubber.

[0009] Preferably, the liquid pumping mechanism includes a first rubber tube, a water pump, a second rubber tube, and a syringe arranged in sequence close to the thin hard tube. Based on the first rubber tube and the second rubber tube, the water pump drives the syringe to perform any one of the operations of injecting liquid, extracting liquid, or blocking liquid into the liquid storage container.

[0010] The present invention has the following beneficial effects: 1. By combining a variable - focus square liquid lens structure with a lens array application, a compound - eye mother lens composed of a liquid sub - lens array with adjustable focal length proposed in this application is constructed. The liquid in the liquid storage container is controlled through a liquid injection hole, causing a pressure difference to form inside and outside the compound - eye mother lens, driving the compound - eye structure to deform. The transparent elastic film is divided into multiple sub - lenses based on the corresponding centers of the first through - hole and the second through - hole, functioning as an "insect compound eye", forming a lens array. The transparent elastic film bulges or depresses accordingly to adjust the focal length of the lens array, and also solves the problem of large spherical aberration. Since no complex devices such as electrodes are required, the measurement and calculation process is greatly simplified, that is, the current focal length is determined by the height or curvature of the film bulge or depression, which has important technical and economic value. Moreover, the compound - eye mother lens structure proposed in this application is simple, easy to manufacture, and low - cost, improving the scope of application. Different shapes of the first through - hole and the second through - hole can increase the duty cycle according to actual applications.

[0011] 2. The present invention also provides a preparation method for a compound - eye mother lens with adjustable focal length, which is used to prepare the compound - eye mother lens composed of the aforementioned liquid sub - lens array with adjustable focal length. This method has the same beneficial effects as the compound - eye mother lens composed of the liquid sub - lens array with adjustable focal length described above, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following - described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0013] Figure 1 FIG. is a schematic structural diagram of a compound - eye mother lens composed of a liquid sub - lens array with adjustable focal length provided by an embodiment of the present invention; Figure 2 FIG. is an exploded view of the compound - eye structure of a compound - eye mother lens composed of a liquid sub - lens array with adjustable focal length provided by an embodiment of the present invention; Figure 3 FIG. is a top - view of the compound - eye structure of a compound - eye mother lens composed of a liquid sub - lens array with adjustable focal length provided by an embodiment of the present invention; Figure 4 FIG. is a schematic structural diagram of the liquid storage container of a compound - eye mother lens composed of a liquid sub - lens array with adjustable focal length provided by an embodiment of the present invention; Figure 5 FIG. is a step - flow chart of a preparation method for a compound - eye mother lens with adjustable focal length provided by an embodiment of the present invention; In the figure: 1. Liquid storage container; 2. Inner skeleton; 3. Transparent elastic film; 4. Outer skeleton; 5. Liquid injection hole. Detailed implementation manners

[0014] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following combines the accompanying drawings and preferred embodiments to detail the specific implementation manners, structures, features and effects of a compound eye mother lens composed of a liquid sub-lens array with adjustable focal length and its preparation method according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs.

[0016] The following specifically describes the specific solutions of a compound eye mother lens composed of a liquid sub-lens array with adjustable focal length and its preparation method provided by the present invention with reference to the accompanying drawings.

[0017] Please refer to Figures 1-4 , which respectively show the structural schematic diagram of a compound eye mother lens composed of a liquid sub-lens array with adjustable focal length provided by the first embodiment of the present invention, the exploded view of the compound eye structure, the top view of the compound eye mother lens, and the structural schematic diagram of the liquid storage container, including: Outer skeleton 4, inner skeleton 2, transparent elastic film 3 and liquid storage container 1; The outer skeleton 4 and the inner skeleton 2 are correspondingly arranged in an arc shape. The outer skeleton 4 is provided with first through holes arrayed along the center, and the inner skeleton 2 is provided with second through holes corresponding to the first through holes. The transparent elastic film 3 is arranged between the inner skeleton 2 and the outer skeleton 4 to form a compound eye structure; The compound eye structure includes at least two. The liquid storage container 1 is arranged between the compound eye structures, and the liquid storage container 1 is provided with a liquid injection hole 5.

[0018] It can be understood that the surface of the existing lens is spherical, resulting in spherical aberration in the lens array, while the compound eye structure in the present application can form a quadratic surface, thereby reducing spherical aberration.

[0019] Preferably, the outer skeleton 4 and the inner skeleton 2 are correspondingly arranged in an arc shape. In this embodiment, the outer skeleton 4 and the inner skeleton 2 are hemispherical surfaces; in practical applications, the curved radian of the outer skeleton 4 and the inner skeleton 2 changes according to the needs of the actual scenario and the imaging clarity requirements, that is, it can start from a plane and bend until a closed surface is formed at 360°.

[0020] Optionally, in this embodiment, the array arrangement of the first through holes and the second through holes is a "well" character structure, that is, a three-dimensional matrix is formed, which can divide the transparent elastic film into nine sub-lenses; in addition, without affecting the overall structure and usability, the array arrangement of the first through holes and the second through holes can be a "cross" character structure, that is, the transparent elastic film is divided into four sub-lenses, and the overall shape is a "field" character structure.

[0021] Regarding the quantity setting of the first through holes and the second through holes, it can be changed according to actual requirements. Generally, the through holes can cover the skeleton. Specifically, when the aperture of the through holes remains unchanged, the number of through holes increases as the skeleton becomes larger; when the number of through holes and the skeleton remain unchanged, the aperture of the through holes increases, and its range of values is generally 1-30 nm to improve flexibility to adapt to specific application scenarios; for example, in a mobile phone lens, the skeleton setting needs to be adjusted smaller, and if it is a vehicle-mounted lens, the skeleton can be adjusted larger.

[0022] Furthermore, the shapes of the first through holes and the second through holes include any one of circular, square, and hexagonal.

[0023] It can be explained that the duty cycle refers to the ratio of the area occupied by the microlens array to the overall area of the lens. Generally, the duty cycle of the square microlens array is high, and the gap between the formed sub-lenses is small. There is a small gap between the circular sub-lenses. Therefore, according to the duty cycle requirements in actual applications, the shapes of the first through holes and the second through holes are adjusted to increase the duty cycle.

[0024] It can be understood that by combining the variable-focus square liquid lens structure and the application of the lens array, the compound eye master lens composed of the liquid sub-lens array with adjustable focal length proposed in this application is constructed. By controlling the liquid in the liquid storage container 1 through the liquid injection hole 5, a pressure difference is formed inside and outside the compound eye master lens, driving the compound eye structure to deform. The transparent elastic film 3 is divided into multiple sub-lenses based on the center corresponding positions of the first through holes and the second through holes, with the function of an "insect compound eye", forming a lens array, and the transparent elastic film 3 bulges or depresses accordingly to adjust the focal length of the lens array, and also solves the problem of large spherical aberration; since no complex devices such as electrodes are required, the measurement and calculation process is greatly simplified, that is, the current focal length is determined by the height or curvature of the film bulge or depression, which has important technical value and economic value; moreover, the compound eye master lens structure proposed in this application is simple, easy to manufacture, and low in cost, improving the scope of application. The different shape settings of the first through holes and the second through holes can increase the duty cycle according to actual applications.

[0025] Please refer to Figure 5, which shows the step flow chart of a preparation method of a compound eye mother lens with adjustable focal length provided by an embodiment of the present invention; that is, the second embodiment of the present invention provides a preparation method of a compound eye mother lens with adjustable focal length for preparing the compound eye mother lens composed of the liquid sub-lens array with adjustable focal length provided by the first embodiment. The method includes: Step S1: Obtain an outer skeleton and an inner skeleton, and perform pretreatment; Step S2: Define the pretreated inner skeleton as the base layer, sequentially cover a transparent elastic film and the pretreated outer skeleton along the vertical direction, and fix them to form a compound eye structure; Step S3: Arrange a liquid storage container between the compound eye structures, insert a thin hard tube based on the liquid injection hole, and use ultraviolet light-curing glue to bond the gap for sealing; Step S4: Connect a liquid pumping mechanism to the other end of the thin hard tube, inject or extract liquid into the liquid storage container through the liquid pumping mechanism, and the liquid storage container correspondingly forms a pressure difference to drive the compound eye structure to deform, driving the transparent elastic film to bulge or sink.

[0026] Preferably, in this embodiment, a photosensitive liquid crystal elastomer (LCE, Liquid Crystalline Elastomer) is used as the transparent elastic film, and a gold nanoparticle (AuNPs) photothermal conversion layer is coated on its surface; without affecting the overall function, a titanium dioxide metasurface structure is etched on the surface of the transparent elastic film to form a broadband achromatic phase modulation layer. Combining the deformation of the compound eye structure caused by the liquid storage container, a "mechanical zoom + metasurface wavefront regulation" two-degree-of-freedom optical modulation is realized; specifically, by adjusting the liquid pressure in the liquid storage container, the transparent elastic film bulges or sinks to change the focal length. At the same time, the surface of the transparent elastic film is covered with countless nanocolumns thinner than hair. The optical path is finely adjusted through the nanocolumns to automatically correct the blur or chromatic aberration caused by the deformation. By combining the two, a large-range zoom can be achieved, and the aberration can be eliminated in real time.

[0027] Further, in step S1, it includes: Step S11: Based on parametric modeling, open a first through hole and a second through hole on the outer skeleton and the inner skeleton respectively, and the first through hole corresponds to the second through hole, and adjust the curvature of the outer skeleton and the inner skeleton; Step S12: Perform pretreatment by cleaning with isopropyl alcohol, UV strengthening, and nano-hydrophobic coating.

[0028] Optionally, the inner skeleton and the outer skeleton can be made by any of 3D printing technology, metal weaving technology, laser etching and micro injection molding processes, wherein 3D printing technology can accurately manufacture the inner skeleton and the outer skeleton by stacking materials layer by layer, which is conducive to customization or small batch production; metal weaving technology mechanically or manually interweaves metal wires, metal strips and other materials into a mesh and bends them to form an inner skeleton and an outer skeleton with specific strength and flexibility; laser etching technology uses a high-energy laser beam to etch on a skeleton without through holes to obtain an inner skeleton and an outer skeleton, which is conducive to miniaturization preparation; micro injection molding process is used to manufacture carbon fiber reinforced polyetheretherketone inner skeleton and outer skeleton, that is, short chopped carbon fiber is mixed with PEEK particles (Polyether EtherKetone Granules, polyetheretherketone particles), injected into a microporous mold at 280°C, demolded after pressure cooling, and a first through hole and a second through hole are opened by a needle-shaped ejector pin embedded in the mold; in addition, the first through hole and the second through hole can be made of shape memory polymer (SMP, Shape Memory The SMP skeleton is manufactured by local irradiation with a near-infrared laser, i.e., a laser beam with a wavelength of 808 nm, to trigger the deformation recovery of the SMP skeleton, and the deformation temperature is 45°C, thereby dynamically adjusting the corresponding distribution of the first through hole and the second through hole.

[0029] It can be understood that the first through hole and the second through hole are opened on the outer frame and the inner frame respectively based on parametric modeling, that is, the structural strength and optical performance of the inner frame and the outer frame are balanced through gradient density design, the curvature of the inner and outer frames are adjusted, and the surface accuracy of the microlens array is ensured by layer-by-layer curvature with a layer thickness of 25 microns and assisted by peripheral tree-like supports; then a series of pretreatments such as isopropyl alcohol cleaning, UV strengthening and nano-hydrophobic coating are performed to improve the transmittance of the microlens, and it has both rigidity and lightweight characteristics.

[0030] Furthermore, the material of the outer frame and the inner frame is any one of PLA, ABS, flexible TPU, PA, titanium alloy, stainless steel, carbon fiber composite material and silicone rubber.

[0031] As an optional implementation, the materials of the inner skeleton and the outer skeleton can be combined and adjusted according to the actual application scenario, that is, according to the different choices of materials, the inner skeleton and the outer skeleton can also be divided into soft skeletons or rigid skeletons, wherein the rigid skeleton can adjust the focal length of the sub-lens, and the flexible skeleton can simultaneously adjust the focal length of the mother lens and the sub-lens; it can be explained that the preparation of the inner and outer skeletons can both be flexible or rigid materials; or the inner skeleton is a flexible material and the outer skeleton is a rigid material; or the outer skeleton is a flexible material and the inner skeleton is a rigid material, thereby improving performance and applicability; for example, in high-intensity application scenarios, the skeleton is usually a rigid material to effectively resist external impact and pressure, provide necessary support and protection, and ensure that the compound eye mother lens can still work normally in harsh environments.

[0032] It should be noted that PLA (Poly-Lactic Acid), namely polylactic acid, is a biodegradable polymer with good biocompatibility and environmental protection characteristics. As a framework material, it can reduce environmental pollution while providing sufficient mechanical strength and heat resistance; ABS (Acrylonitrile Butadiene Styrene) has excellent impact resistance and heat resistance, can withstand harsh environments, and maintain good processing performance at the same time; flexible TPU (Thermoplastic Polyurethane) has excellent flexibility and wear resistance, can adapt to various complex working conditions, and ensure the stability and durability of the framework; PA (Polyamide) has the advantages of high strength, high wear resistance and good chemical resistance, and can maintain good performance under high load and harsh environments; titanium alloy is a metal material with high strength and low density, has good corrosion resistance and high temperature resistance, and is suitable for the preparation of frameworks that require lightweight and high reliability; stainless steel has good corrosion resistance, ensuring the stability of the framework in various environments; carbon fiber composite materials, with their extremely high strength-to-weight ratio and stiffness-to-weight ratio, are especially suitable for the aerospace and high-end manufacturing fields; silicone rubber has excellent flexibility and good thermal stability, can maintain its physical and chemical properties unchanged in high-temperature environments, ensure that the compound eye mother lens will not be damaged due to temperature changes during use in high-temperature environments, and the silicone rubber has good light transmittance and will not have a negative impact on the imaging quality, ensuring clear images are provided; that is, the materials used to prepare the inner and outer frameworks each have their unique characteristics and advantages, and in practical applications, they are selected according to specific application requirements and performance requirements.

[0033] It should be noted that in step S3, the liquid storage container is arranged between the compound eye structures. A thin hard tube is inserted based on the injection hole and the gap is sealed with ultraviolet curable adhesive; among them, the ultraviolet curable adhesive has extremely strong adhesion performance and can quickly cure under ultraviolet irradiation to form a strong and sealed connection, which can ensure the reliability between the liquid storage container and the compound eye structure to prevent the liquid in the liquid storage container from leaking.

[0034] Furthermore, in step S4, the liquid pumping mechanism includes a first rubber tube, a water pump, a second rubber tube and a syringe arranged in sequence close to the thin hard tube. Based on the first rubber tube and the second rubber tube, the syringe is driven by the water pump to perform any one of the operations of injecting liquid, extracting liquid or shutting off liquid into the liquid storage container.

[0035] Specifically, a first rubber tube is used to connect the thin rigid tube, and the other end of the thin rigid tube is connected to the liquid injection hole of the liquid storage container. The other end of the first rubber tube is successively connected to a water pump, a second rubber tube, and a syringe. After injecting or extracting liquid into the liquid storage container through the syringe, a pressure difference is formed inside and outside the liquid storage container, driving the deformation of the compound eye structure, and the transparent elastic film will bulge or dent accordingly. The bulging film is divided into multiple sub-lenses under the action of the first through hole and the second through hole, constituting the function of an "insect compound eye" and forming a lens array. In addition, the amount of liquid injected or extracted can control the amplitude of the bulge or dent of the transparent elastic film. For example, for every 100 ml of liquid added, the liquid level height increases correspondingly to form a certain increase in liquid pressure. According to different actual requirements, the amount of liquid in the liquid storage container will be adjusted correspondingly according to the liquid pumping mechanism, thereby indirectly adjusting the lens focal length and forming a compound eye master mirror composed of a liquid sub-lens array with adjustable focal length.

[0036] It should be noted that the above sequence of embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0037] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key point of each embodiment is to illustrate the differences from other embodiments.

Claims

1. A compound eye mother mirror composed of a liquid sub-lens array with adjustable focal length, characterized in that, include: An exoskeleton, an endoskeleton, a transparent elastic film and a liquid storage container; The outer frame and the inner frame are both arranged in an arc shape, the outer frame is provided with a first through hole along the central array, the inner frame is provided with a second through hole corresponding to the first through hole, and the transparent elastic film is arranged between the inner frame and the outer frame to form a compound eye structure; The compound eye structures include at least two, the liquid storage container is arranged between the compound eye structures, and a liquid injection hole is opened on the liquid storage container.

2. The compound eye master mirror composed of a liquid sub-lens array with adjustable focal length according to claim 1, characterized in that, The shapes of the first through hole and the second through hole include any one of a circle, a square and a hexagon.

3. A preparation method of a compound eye master mirror with adjustable focal length, characterized in that, A method for preparing a compound eye mother lens composed of a focal length adjustable liquid sub-lens array as claimed in any one of claims 1 to 2, the method comprising: Obtaining the exoskeleton and the endoskeleton and performing preprocessing; The pretreated inner frame is defined as the base layer, and a transparent elastic film and the pretreated outer frame are sequentially covered in the vertical direction to form a compound eye structure; The liquid storage container is arranged between the compound eye structures, a thin hard tube is inserted into the injection hole, and the gap is sealed by gluing with ultraviolet shadowless glue; A liquid pumping mechanism is connected to the other end of the thin hard tube, and liquid is injected or extracted into the liquid storage container through the liquid pumping mechanism. The corresponding pressure difference formed in the liquid storage container drives the compound eye structure to deform, causing the transparent elastic film to bulge or sink.

4. The preparation method of a compound eye mother lens with adjustable focal length according to claim 3, characterized in that, Get the exoskeleton and endoskeleton and perform preprocessing, including: Based on parametric modeling, a first through hole and a second through hole are respectively opened on the outer frame and the inner frame, and the first through hole corresponds to the second through hole, and the curvature of the outer frame and the inner frame is adjusted; Isopropyl alcohol cleaning, UV strengthening and nano-hydrophobic coating were used for pretreatment.

5. The preparation method of a compound eye master mirror with adjustable focal length according to claim 4, characterized in that, The material of the outer frame and the inner frame is any one of PLA, ABS, flexible TPU, PA, titanium alloy, stainless steel, carbon fiber composite material and silicone rubber.

6. The preparation method of a compound eye mother lens with adjustable focal length according to claim 3, characterized in that, The liquid pumping mechanism includes a first rubber tube, a water pump, a second rubber tube and a syringe which are sequentially arranged near the thin hard tube. Based on the first rubber tube and the second rubber tube, the water pump drives the syringe to inject liquid, extract liquid or cut off liquid from the liquid storage container.

Images