Method for preparing high-precision micro-lens array in liquid environment and manufacturing system

Abstract

The invention relates to the technical field of micro-lens array printing, provides a method for preparing a high-precision micro-lens array in a liquid environment and a manufacturing system, and can realize preparation of the high-precision micro-lens array in the liquid environment through a printing technology of generating liquid drops through constrained interface vibration. An X-axis motion platform, a Y-axis motion platform and a Z-axis motion platform are used for controlling a piezoelectric ceramic spray head to generate liquid drops in carrier liquid in a carrier liquid container through interface vibration, the liquid drops are sequentially printed on micro lenses to form the micro lens array, the micro lens array with the editable size can be manufactured through the method, and extremely high stability is achieved. The preparation environment of the micro-lens array is changed, liquid drops can be effectively protected by carrier liquid in the printing process, the problems that volatilization occurs when a volatile printing material is used, the shape of the micro-lens is affected by airflow in the preparation process and the like can be avoided or relieved, and the manufacturing process of the micro-lens array is more stable.

Description

Technical Field

[0001] The present invention relates to the technical field of microlens array printing, and in particular to a method and a manufacturing system for preparing a high-precision microlens array in a liquid environment. Background Art

[0002] The size of each lens in the microlens array is between 10 and 100 microns, and it is lightweight, miniaturized, and highly integrated. The microlens array can achieve efficient light focusing, light splitting, and uniform illumination, and has important applications in optical systems, optical communications, imaging and sensing, consumer electronics, and biomedicine.

[0003] At present, the manufacturing methods of microlens arrays mainly include photolithography technology, mold replication technology and inkjet printing technology. Inkjet printing technology has attracted much attention in recent years due to its high flexibility, uniformity and material adaptability. At present, the mainstream process of inkjet printing is still carried out in the air. The printing process is easily affected by gravity and surrounding airflow disturbances, which interferes with the printing accuracy of microlenses. In addition, with the in-depth application of micro-nano optical components in modern optical imaging, optical communication and display fields, higher requirements are placed on the manufacturing accuracy of microlens arrays. Conventional inkjet printing technology improves printing accuracy by reducing the size of the nozzle. However, after the nozzle size is reduced, it is very easy to clog during use, which in turn generates huge manufacturing and maintenance costs. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method and a manufacturing system for preparing a high-precision microlens array by using a printing technology that generates droplets through constrained interface vibration in a liquid environment. The method can produce a microlens array with editable size and extremely high stability.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a manufacturing system for a microlens array, comprising a liquid-carrying container fixed to the central area of ​​an X, Y, and Z three-axis motion platform through a support frame, a substrate and a stored carrier liquid are arranged in the liquid-carrying container, and an editable excitation power supply for adjusting the pressure in a piezoelectric ceramic nozzle according to the size required for microlens preparation, the X, Y, and Z three-axis motion platform controls the piezoelectric ceramic nozzle to generate droplets in the carrier liquid in the liquid-carrying container through interface vibration to sequentially print microlenses to form a microlens array; The piezoelectric ceramic nozzle includes a piezoelectric actuator installed on the outer wall of a piezoelectric ceramic glass sleeve, the piezoelectric ceramic glass sleeve is filled with printing liquid, the electrical signal generated by the editable excitation power supply drives the piezoelectric actuator to produce mechanical deformation, so that the piezoelectric ceramic glass sleeve is in an expansion or contraction state and negative pressure waves or positive pressure waves are generated therein, and under the cyclic action of negative and positive pressure waves, the neck of the piezoelectric ceramic nozzle is broken during the process of extrusion, back-absorption and re-extrusion of the printing liquid, and the droplets fall on the substrate in the carrier liquid under their own gravity to form microlenses.

[0006] Furthermore, the negative pressure wave or the positive pressure wave is split into two and propagates synchronously to both sides along the inner pipe of the piezoelectric ceramic glass sleeve; At the initial moment, driven by the electrical signal, the piezoelectric actuator propagates two negative pressure waves from the middle to both ends of the piezoelectric ceramic glass sleeve. One of the negative pressure waves reaches the nozzle end of the piezoelectric ceramic glass sleeve, causing the nozzle end to suck back the printing liquid, and the other negative pressure wave reaches the opening end at the same time, causing opposite reflection to form a reflected wave. One of the two positive pressure waves is linearly superimposed with the reflected wave and moves toward the nozzle end to realize the extrusion of the printing liquid, and the other positive pressure wave propagating toward the opening end cancels out the negative pressure wave.

[0007] Furthermore, the X, Y, Z three-axis motion platform includes a UV light source X-direction slider, a piezoelectric ceramic nozzle X-direction slider, a Y-direction slider, a piezoelectric ceramic nozzle Z-direction slider, and a UV light source Z-direction slider. The piezoelectric ceramic nozzle Z-direction slider is equipped with a piezoelectric ceramic nozzle upper clamp and a piezoelectric ceramic nozzle lower clamp to fix the piezoelectric ceramic nozzle, and the UV light source Z-direction slider is equipped with a UV light source upper clamp and a UV light source lower clamp to fix the UV light source.

[0008] Furthermore, the piezoelectric ceramic nozzle and the UV light source can be moved in the X, Y, and Z directions respectively, and the UV light source quickly irradiates the printing liquid for light curing after the microlens array is printed.

[0009] Furthermore, the printing liquid is a photocurable liquid material with a viscosity of 1-40 mPa·s, the carrier liquid is any one of silicone oil, fluorinated liquid, and mineral oil, the printing liquid and the carrier liquid are immiscible with each other, and the density of the printing liquid is greater than the density of the carrier liquid.

[0010] Furthermore, the substrate is any one of polymethyl methacrylate, polycarbonate, and borosilicate glass, and the substrate is immersed in the carrier liquid and does not react with the carrier liquid.

[0011] Furthermore, the printing liquid consists of 0.5 wt % of a photoinitiator and 99.5 wt % of polyethylene glycol diacrylate.

[0012] The technical solution also provides a preparation method applied to the above-mentioned microlens array manufacturing system, the method comprising the following steps: S1. Start the back pressure source, the pressure in the liquid storage bottle increases, the printing liquid flows along the liquid outlet conduit into the piezoelectric ceramic glass sleeve, and the output pressure of the back pressure source is adjusted so that the liquid to be printed is stabilized at the nozzle outlet and forms a stable interface with the carrier liquid at the nozzle; S2. Start the editable excitation power supply, which generates a periodically changing voltage. The piezoelectric actuator is mechanically deformed under the drive of the electrical signal, and the piezoelectric ceramic glass sleeve in the piezoelectric ceramic nozzle is deformed, thereby generating a pressure wave in the pipe, causing the printing liquid to be extruded and sucked back at the nozzle. When the piezoelectric ceramic nozzle is subjected to a reasonable excitation waveform, the printing liquid in the nozzle is extruded, sucked back, and re-extruded, and the neck is broken during this process. The droplets in the carrier liquid eventually fall on the substrate under the action of gravity; S3, a printing droplet breaks and forms, that is, one microlens printing is completed, and the piezoelectric ceramic nozzle moves to the next printing position under the control of the X, Y, and Z three-axis motion platform; S4, repeat the above steps, each time the microlens is printed, the voltage change cycle and amplitude generated by the editable excitation power supply can be edited according to the size requirements of the next microlens. After the microlens droplet is printed, wait for all the printed droplets to fall onto the substrate to form a stable microlens shape; S5. After the microlens array is printed, the piezoelectric ceramic nozzle is lifted to the outside of the liquid carrier container and moved to the outside of the substrate area by the X, Y, and Z three-axis motion platform. After the piezoelectric ceramic nozzle is returned to its original position, the UV light source is moved to the top of the printing area by the X, Y, and Z three-axis motion platform to perform light curing on the printed liquid.

[0013] Furthermore, the editable excitation power supply generates a periodically changing voltage of -100-100V with a period of 50μs.

[0014] By means of the above technical solution, the present invention provides a method and a manufacturing system for preparing a high-precision microlens array in a liquid environment, which has at least the following beneficial effects: 1. The present invention changes the preparation environment of the microlens array. The carrier liquid can effectively protect the droplets during the printing process, and can avoid or alleviate the volatilization when using volatile printing materials and the airflow during the preparation process affecting the shape of the microlens. The problem makes the microlens array production process more stable.

[0015] 2. The present invention can realize the printing of multi-scale microlens arrays, and can present microlenses of different sizes on the same substrate to optimize its optical performance. It can realize the control of the size of microlenses and print microlenses of different sizes under the premise of using the same nozzle without changing the nozzle size, thereby reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 is a schematic structural diagram of a microlens array manufacturing system in the present invention; Figure 2 For the present invention Figure 1 The enlarged view of point A in the middle; Figure 3 It is a structural schematic diagram and a partial schematic diagram of the microlens array manufacturing system of the present invention; Figure 4 A schematic diagram of the internal structure of the piezoelectric ceramic nozzle and its connection with an editable excitation power supply in the present invention; Figure 5 A schematic diagram of the printing process of high-precision micro-nano droplets printed by constrained interface vibration in the present invention; Figure 6 Schematic diagram of the formation of microlenses in the present invention; Figure 7 is a schematic diagram of the printing result of the microlens array in the present invention; Figure 8 It is a partial cross-sectional view of the printing result of the microlens array in the present invention.

[0017] In the figure: 1. Editable excitation power supply; 2. Negative wire; 3. Positive wire; 4. Back pressure source; 5. Liquid storage bottle; 6. Bottle stopper; 7. Air inlet duct; 8. Liquid outlet duct; 9. Support frame; 10. Liquid carrier container; 11. UV light source X-direction slider; 12. Piezoelectric ceramic nozzle X-direction slider; 13. Y-direction slider; 14. Piezoelectric ceramic nozzle upper fixture; 15. Piezoelectric ceramic nozzle lower fixture; 16. Piezoelectric ceramic nozzle Z-direction slider; 17. Piezoelectric ceramic nozzle; 18. UV light source upper fixture; 19. UV light source lower fixture; 20. UV light source Z-direction slider; 21. UV light source; 22. Piezoelectric actuator; 23. Piezoelectric ceramic glass sleeve; 24. Substrate; 25. Printing liquid; 26. Carrier liquid; 27. Microlens array. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0019] At present, the manufacturing methods of microlens arrays mainly include photolithography technology and mold replication technology. Photolithography technology uses photosensitive materials and ultraviolet light exposure combined with a mask to make microlens arrays. First, a layer of photoresist is coated on the substrate, and then the preliminary shape of the microlens is formed on the photoresist by controlling the light exposure and development process. Then, through the thermal remelting technology, the photoresist is heated to flow and form a smooth curved surface to construct the lens structure. Photolithography technology can achieve high-precision and high-uniformity microlens arrays, but due to the complexity of the equipment, high cost and the limited processability of the photoresist, there are certain limitations for the production of large-area arrays and the preparation of microlenses with high thickness. The mold replication method usually makes a master mold or a prototype mold, and then uses methods such as hot pressing, soft embossing or injection molding to replicate the microlens structure on the target substrate. This method is suitable for large-scale production, has low cost, and the mold can be reused. However, the mold manufacturing process is complicated and costly, and the accuracy of the mold directly determines the quality of the replicated lens. In addition, during the replication process, microlens arrays are prone to structural deformation, material shrinkage or surface defects. Especially for flexible substrates or larger microlens arrays, accuracy and uniformity are difficult to guarantee.

[0020] Inkjet printing technology has attracted much attention in recent years due to its high flexibility, uniformity and material adaptability. This technology has high design flexibility and digital control capabilities, and is suitable for application scenarios that require customization, rapid iteration and small-batch production. Through computer-aided design, the size, shape and arrangement of the lens can be precisely controlled to achieve on-demand deposition, eliminating the expensive mask preparation process, and can be directly formed in one step through UV curing, thereby significantly simplifying the manufacturing process and improving material utilization. At the same time, the equipment cost is low, suitable for rapid prototyping and small-batch customized production, and can be applied on a variety of substrates, greatly enhancing the design and application potential of microlens arrays. At present, the mainstream process of inkjet printing is still carried out in the air, and the printing process is easily affected by gravity and surrounding airflow disturbances, which interferes with the printing accuracy of microlenses; in addition, with the in-depth application of micro-nano optical components in modern optical imaging, optical communication and display fields, higher requirements are placed on the manufacturing accuracy of microlens arrays. Conventional inkjet printing technology improves printing accuracy by reducing the size of the nozzle. However, after the nozzle size is reduced, it is very easy to clog during use, which in turn generates huge manufacturing and maintenance costs.

[0021] The above problems are technical difficulties that need to be solved in the field of microlens array printing when inkjet printing technology is applied. Please refer to Figure 1-Figure 4 , this embodiment proposes a manufacturing system for a microlens array, which avoids or alleviates the problems of volatilization and airflow affecting the shape of microlenses during the preparation process when using volatile printing materials, so as to make the microlens array manufacturing process more stable. The manufacturing system includes a liquid-carrying container 10 fixed to the central area of ​​the X, Y, and Z three-axis motion platform by a support frame 9, a substrate 24 and a stored carrier 26 are arranged in the liquid-carrying container 10, and an editable excitation power supply 1 that drives the piezoelectric ceramic nozzle 17 through a variable electrical signal according to the required size of the microlens preparation. The editable excitation power supply can generate a periodically changing voltage of -100 to 100 volts, and the period and amplitude can be arbitrarily edited according to the required size of the microlens production. The X, Y, and Z three-axis motion platform controls the piezoelectric ceramic nozzle 17 to generate droplets in the carrier 26 in the liquid-carrying container 10 through interface vibration to print microlenses in sequence to form a microlens array 27. Among them, the common inner diameter size of the nozzle of the piezoelectric ceramic nozzle 17 is 50 to 100 μm.

[0022] In this embodiment, the piezoelectric ceramic nozzle 17 includes a piezoelectric actuator 22 installed on the outer wall of a piezoelectric ceramic glass sleeve 23. The piezoelectric ceramic glass sleeve 23 is filled with printing liquid 25. The electrical signal generated by the editable excitation power supply 1 drives the piezoelectric actuator 22 to produce mechanical deformation, so that the piezoelectric ceramic glass sleeve 23 is in an expansion or contraction state and negative pressure waves or positive pressure waves are generated therein. Under the cyclic action of negative and positive pressure waves, the neck of the printing liquid 25 of the piezoelectric ceramic nozzle 17 breaks during the process of extrusion, back-absorption and re-extrusion, and the droplets fall on the substrate 24 in the carrier liquid 26 under their own gravity to form a microlens.

[0023] As a further implementation option of this embodiment, the negative pressure wave or the positive pressure wave is divided into two and propagates synchronously to both sides along the inner pipe of the piezoelectric ceramic glass sleeve 23. At the initial moment, the piezoelectric actuator 22 is driven by an electrical signal, and two negative pressure waves propagate from the middle of the piezoelectric ceramic glass sleeve 23 to both ends, one of which reaches the nozzle end of the piezoelectric ceramic glass sleeve 23 to cause the back suction of the printing liquid 25, and the other negative pressure wave reaches the opening end at the same time and undergoes opposite reflection to form a reflected wave. Subsequently, the editable excitation power supply 1 drives the piezoelectric ceramic glass sleeve 23 to contract, generating a positive pressure wave in the pipe, one of the two positive pressure waves is linearly superimposed with the reflected wave and moves toward the nozzle end to realize the extrusion of the printing liquid 25, and the other positive pressure wave propagating to the opening end cancels out the negative pressure wave. In this embodiment, the piezoelectric ceramic nozzle drives the piezoelectric actuator 22 through the editable excitation power supply 1 to produce mechanical deformation, so that the piezoelectric ceramic glass sleeve 23 is in an expansion or contraction state and a negative pressure wave or a positive pressure wave is generated therein to prepare the microlens. The working principle is: The inner cavity of the piezoelectric ceramic glass sleeve 23 can be regarded as a cylindrical acoustic waveguide. When the excitation frequency of the acoustic wave in the pipe is less than the cutoff frequency of the pipe, its propagation in the pipe can be regarded as a plane wave. The calculation formula is: ; In the formula, is the nozzle channel radius of the piezoelectric ceramic nozzle; is the speed of sound waves traveling inside the pipe.

[0024] The corresponding cutoff frequency can be obtained by the above formula It is much larger than the excitation frequency of piezoelectric ceramics, so the sound wave in the channel can be regarded as a plane wave. In summary, the sound wave in the nozzle channel can be regarded as a linear one-dimensional plane sound wave for analysis, which satisfies the linear superposition principle. Assume an incident wave The cross-sectional area is The median cross-sectional area of ​​the pipe is The incident wave propagates in a pipe with a cross-sectional area that is different from the media on both sides. exist and Reflection and transmission will occur at the interface, corresponding to the reflected wave and transmitted wave ; The corresponding particle velocities are expressed as , and There are two boundary conditions at the interface. The first is that the sound pressure is continuous, namely: ; Secondly, according to the law of conservation of mass, the volume velocity continuity condition should be met, that is: ; Combining the two equations, the sound pressure ratio can be obtained as: ; From the above formula, we can know that the reflection of sound waves is related to the ratio of the cross-sectional areas of the two tubes. hour, , we can see that the reflected pressure wave will change from positive to negative or from negative to positive, which is the case when the pressure wave is reflected at the open end; and when hour, , the sound wave will be completely reflected while the properties remain unchanged, that is, the pressure wave is reflected at the nozzle end.

[0025] Based on the above principle, in this embodiment, a driving signal is applied through an editable excitation power supply 1 at the initial moment, so that the piezoelectric ceramic glass sleeve 23 expands, and then a negative pressure wave is formed in the piezoelectric ceramic glass sleeve 23, which is divided into two and propagates synchronously along both sides of the pipeline. When the negative pressure wave reaches the closed end, it will cause a weak back suction at the interface at the nozzle. Since the size of the nozzle is much smaller than the size of the piezoelectric ceramic glass sleeve 23, the pressure wave is reflected with the same sign at the nozzle end (which can be regarded as the closed end), that is, the properties of the pressure wave remain unchanged, and the direction of movement is reversed. The negative pressure wave moving in the other direction reaches the open end at the same time, and the pressure wave will be reflected with the opposite sign, that is, the properties of the pressure wave change (the negative pressure wave is reflected as a positive pressure wave), and the direction of movement is also reversed.

[0026] Subsequently, the editable excitation power supply 1 drives the piezoelectric ceramic glass sleeve 23 to contract, generating a positive pressure wave in the pipe, which is also divided into two and propagates synchronously to both sides. By adjusting the action time of the editable excitation power supply 1, the moment when the pressure waves reflected from both sides meet in the middle can correspond to the moment when the positive pressure wave is applied, and the reflected wave and the pressure wave at this moment can be well superimposed. In this case, the positive pressure wave and the negative pressure wave propagating toward the opening end cancel each other out, while the two positive pressure waves moving toward the nozzle end are linearly superimposed, achieving energy enhancement, so that the printing liquid caused by the pressure wave reaching the nozzle is ejected more obviously.

[0027] Finally, the pressure wave reciprocates in the piezoelectric ceramic glass sleeve 23 and gradually weakens. Each time the pressure wave propagates to the nozzle end, it is reflected with the same sign, that is, the properties of the pressure wave remain unchanged, and the direction of movement is reversed. When the pressure wave propagates to the opening end, it is reflected with the opposite sign, that is, the properties of the pressure wave change (negative pressure wave is reflected as positive pressure wave), and the direction of movement is also reversed, so that the printing liquid repeatedly experiences ejection and reabsorption.

[0028] As a further implementation option of this embodiment, the X, Y, and Z three-axis motion platform includes a UV light source X-direction slider 11, a piezoelectric ceramic nozzle X-direction slider 12, a Y-direction slider 13, a piezoelectric ceramic nozzle Z-direction slider 16, and a UV light source Z-direction slider 20. The piezoelectric ceramic nozzle Z-direction slider 16 is equipped with a piezoelectric ceramic nozzle upper fixture 14 and a piezoelectric ceramic nozzle lower fixture 15 to fix the piezoelectric ceramic nozzle 17, and the UV light source Z-direction slider 20 is equipped with a UV light source upper fixture 18 and a UV light source lower fixture 19 to fix the UV light source 21. The piezoelectric ceramic nozzle 17 and the UV light source 21 can move in the X, Y, and Z directions respectively. After the microlens array is printed, the UV light source 21 quickly irradiates the printing liquid 25 for light curing.

[0029] More specifically, the X, Y, and Z three-axis motion platform controls the piezoelectric ceramic nozzle 17 to achieve precise positioning and continuous motion to complete the microlens array printing task by converting G code instructions into specific motion control signals.

[0030] More specifically, the liquid storage bottle 5 has a stopper 6 at the mouth of which only two insertion holes for catheters are left, so that the inside of the bottle is isolated from the outside air. The bottle stores printing liquid 25. The back pressure source 4 is connected to the air inlet catheter 7 and inserted into the liquid storage bottle 5. The end of the air inlet catheter 7 is not inserted into the printing liquid 25 and maintains a certain distance from the liquid surface; the liquid outlet catheter 8 is inserted into the printing liquid 25, and the printing liquid 25 is transferred to the piezoelectric ceramic nozzle 17 through the liquid outlet catheter 8 under the drive of the back pressure source 4.

[0031] The printing liquid 25 is a photocurable liquid material with a viscosity of 1-40 mPa·s, high optical transparency and stability, and is stored in a liquid storage bottle 5. The printing liquid 25 is composed of 0.5 wt% of a photoinitiator and 99.5 wt% of polyethylene glycol diacrylate. The carrier liquid 26 is any one of silicone oil, fluorinated liquid, and mineral oil, and silicone oil is further used as the carrier liquid 26, which is stored in the carrier liquid container 10. The printing liquid 25 and the carrier liquid 26 are immiscible with each other, and the density of the printing liquid 25 is greater than the density of the carrier liquid 26. Before printing, the contact angle between the microlens array and the substrate is adjusted according to requirements. The substrate 24 can use one of polymethyl methacrylate, polycarbonate, and borosilicate glass, and the substrate can be selected according to specific printing requirements. More specifically, the substrate 24 uses polymethyl methacrylate, and the substrate 24 is hydrophilically treated before printing. The substrate 24 is immersed in the carrier liquid 26 and does not react with the carrier liquid 26.

[0032] like Figure 4 As shown, the editable excitation power supply 1 connects the positive signal output end to the outer wall electrode of the piezoelectric actuator 22 through the positive wire 3, and connects the negative signal output end to the inner wall electrode of the piezoelectric actuator 22 through the negative wire 2, so as to realize the electrical signal drive of the piezoelectric ceramic nozzle 17.

[0033] like Figure 5-Figure 8 As shown, based on the above-mentioned microlens array manufacturing system, this embodiment further proposes a preparation method for cooperating with each other to prepare a microlens array, and the method includes the following steps: S1. Store printing liquid 25 in the liquid storage bottle 5, place a substrate in the liquid carrier container 10 and add a sufficient amount of carrier liquid 26, the depth of the carrier liquid 26 reaches 500 μm.

[0034] S2. Select a piezoelectric ceramic nozzle 17 with a nozzle size of 60 μm, adjust the piezoelectric ceramic nozzle 17 to a corner of the substrate 24, with a distance of 20 μm from both sides of the substrate 24, and a nozzle distance of 120 μm from the substrate. Set this as the origin position for starting printing and input the designed G code into the X, Y, and Z three-axis motion platform.

[0035] S3, start the back pressure source 4, the pressure in the liquid storage bottle 5 increases, the printing liquid 25 flows along the liquid outlet conduit 8 into the piezoelectric ceramic glass sleeve 23, and the liquid level is stabilized at the nozzle outlet.

[0036] S4, start the editable excitation power supply 1, the editable excitation power supply 1 generates a periodic voltage with a period of 50μs and a voltage of -100-100V, such as Figure 5 As shown, the piezoelectric actuator 22 is mechanically deformed under the drive of the electrical signal, which directly causes the piezoelectric ceramic glass sleeve 23 to deform to a certain extent, generating a pressure wave in the pipe. When the piezoelectric actuator 22 is squeezed inward, the printing liquid 25 is squeezed out, and when the piezoelectric actuator 22 is expanded outward, the printing liquid 25 is sucked back. When the printing liquid 25 in the piezoelectric ceramic nozzle 17 is squeezed out, the neck is broken during the process of extrusion, sucking back, and then extrusion, the droplets in the carrier liquid 26 finally fall on the substrate 24 under the action of gravity.

[0037] S5, such as Figure 6 As shown, a printing droplet is broken, that is, a microlens printing is completed, and the piezoelectric ceramic nozzle 17 moves 90 μm along the X direction with the XYZ three-axis motion platform to the next printing position, and the droplet in the carrier liquid 26 finally falls on the substrate 24 under the action of gravity.

[0038] S6. After repeating the above steps to print a row of five microlenses along the X direction on the substrate 24, the X, Y, and Z three-axis motion platform moves 90 μm along the Y direction to the next printing position, and the excitation power supply 1 can be edited to change the voltage change cycle and amplitude to continue the microlens printing task.

[0039] S7, after all the droplets fall on the substrate 24 and the lens shape tends to be stable, turn on the UV light source 21 and irradiate for 2 minutes to complete the curing, stop the UV light source 21, the editable excitation power supply 1 and the back pressure source 4 in sequence, and take out the microlens array 27. Figure 7 and Figure 8 shown.

[0040] This embodiment can realize the printing of multi-scale microlens arrays, and can present microlenses of different sizes on the same substrate to optimize its optical performance. It can realize the control of the size of microlenses and print microlenses of different sizes without changing the nozzle size while using the same nozzle, thereby reducing production costs.

[0041] This embodiment changes the preparation environment of the microlens array. The carrier liquid can effectively protect the droplets during the printing process, and can avoid or alleviate the volatilization when using volatile printing materials and the airflow during the preparation process affecting the shape of the microlenses. Problems such as this can make the microlens array manufacturing process more stable.

[0042] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the above embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0043] The above implementation methods have been described in detail. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A manufacturing system for a microlens array, comprising a liquid-carrying container (10) fixed to the central area of ​​an X, Y, Z three-axis motion platform by a support frame (9), a substrate (24) and a stored liquid (26) being arranged in the liquid-carrying container (10), and an editable excitation power supply (1) for adjusting the pressure in a piezoelectric ceramic nozzle (17) according to the size required for microlens preparation, characterized in that: The X, Y, and Z three-axis motion platform controls the piezoelectric ceramic nozzle (17) to generate droplets in the carrier liquid (26) in the carrier liquid container (10) through interface vibration to sequentially print microlenses to form a microlens array (27); The piezoelectric ceramic nozzle (17) comprises a piezoelectric actuator (22) mounted on the outer wall of a piezoelectric ceramic glass sleeve (23); the piezoelectric ceramic glass sleeve (23) is filled with a printing liquid (25); the electrical signal generated by the editable excitation power supply (1) drives the piezoelectric actuator (22) to produce mechanical deformation, so that the piezoelectric ceramic glass sleeve (23) is in an expansion or contraction state and a negative pressure wave or a positive pressure wave is generated therein; under the cyclic action of the negative pressure wave and the positive pressure wave, the neck of the printing liquid (25) of the piezoelectric ceramic nozzle (17) is broken during the process of extrusion, back suction and re-extrusion, and the liquid droplets fall on the substrate (24) in the carrier liquid (26) under their own gravity to form a microlens.

2. The microlens array manufacturing system according to claim 1, characterized in that: The negative pressure wave or the positive pressure wave is split into two and propagates synchronously to both sides along the inner pipe of the piezoelectric ceramic glass sleeve (23); At the initial moment, the piezoelectric actuator (22) is driven by an electrical signal, and two negative pressure waves propagate from the middle of the piezoelectric ceramic glass sleeve (23) to both ends, one of which reaches the nozzle end of the piezoelectric ceramic glass sleeve (23) to cause the nozzle end to suck back the printing liquid (25), and the other negative pressure wave reaches the opening end at the same time and is reflected with opposite signs to form a reflected wave; One of the two positive pressure waves is linearly superimposed with the reflected wave and moves toward the nozzle end to achieve extrusion of the printing liquid (25), and the other positive pressure wave propagates toward the opening end to offset the negative pressure wave.

3. The microlens array manufacturing system according to claim 1, characterized in that: The X, Y, Z three-axis motion platform comprises a UV light source X-direction slider (11), a piezoelectric ceramic nozzle X-direction slider (12), a Y-direction slider (13), a piezoelectric ceramic nozzle Z-direction slider (16), and a UV light source Z-direction slider (20); the piezoelectric ceramic nozzle Z-direction slider (16) is equipped with a piezoelectric ceramic nozzle upper clamp (14) and a piezoelectric ceramic nozzle lower clamp (15) for fixing the piezoelectric ceramic nozzle (17); and the UV light source Z-direction slider (20) is equipped with a UV light source upper clamp (18) and a UV light source lower clamp (19) for fixing the UV light source (21).

4. The microlens array manufacturing system according to claim 3, characterized in that: The piezoelectric ceramic nozzle (17) and the UV light source (21) can move in the X, Y, and Z directions respectively, and the UV light source (21) quickly irradiates the printing liquid (25) for light curing after the microlens array printing is completed.

5. The microlens array manufacturing system according to claim 1, characterized in that: The printing liquid (25) is a photocurable liquid material with a viscosity of 1-40 mPa·s, the carrier liquid (26) is any one of silicone oil, fluorinated liquid, and mineral oil, the printing liquid (25) and the carrier liquid (26) are immiscible with each other, and the density of the printing liquid (25) is greater than the density of the carrier liquid (26).

6. The microlens array manufacturing system according to claim 1, characterized in that: The substrate (24) is any one of polymethyl methacrylate, polycarbonate, and borosilicate glass. The substrate (24) is immersed in the carrier liquid (26) and does not react with the carrier liquid (26).

7. The microlens array manufacturing system according to claim 5, characterized in that: The printing liquid (25) is composed of 0.5 wt % of a photoinitiator and 99.5 wt % of polyethylene glycol diacrylate.

8. A method for preparing a microlens array manufacturing system according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: S1. Start the back pressure source, the pressure in the liquid storage bottle increases, the printing liquid flows along the liquid outlet conduit into the piezoelectric ceramic glass sleeve, and the output pressure of the back pressure source is adjusted so that the liquid to be printed is stabilized at the nozzle outlet and forms a stable interface with the carrier liquid at the nozzle; S2, start the editable excitation power supply, the editable excitation power supply generates a periodically changing voltage, the piezoelectric actuator is mechanically deformed under the drive of the electrical signal, the piezoelectric ceramic glass sleeve in the piezoelectric ceramic nozzle is deformed, and then a pressure wave is generated in the pipeline, so that the printing liquid is extruded and sucked back at the nozzle; S3, a printing droplet breaks and forms, that is, one microlens printing is completed, and the piezoelectric ceramic nozzle moves to the next printing position under the control of the X, Y, and Z three-axis motion platform; S4, repeat the above steps, after each microlens is printed, the voltage variation period and amplitude generated by the editable excitation power supply can be edited arbitrarily according to the size requirements of the next microlens; S5. After the piezoelectric ceramic nozzle returns to its original position, the UV light source is controlled by the X, Y, and Z three-axis motion platform to move to the top of the printing area to perform photocuring operation on the printing liquid.

9. The microlens array manufacturing system according to claim 8, characterized in that: The editable excitation power supply generates a periodically changing voltage of -100-100V with a period of 50μs.

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