Electrowetting liquid lens and preparation method and preparation system thereof

Abstract

The invention discloses an electrowetting liquid lens and a preparation method and a preparation system thereof. The electrowetting liquid lens includes: a packaging housing; the transparent electrode is arranged on the bottom wall of the packaging cavity; the side wall electrode is provided with a through cavity, the transparent electrode seals and covers the lower end of the cavity to define a liquid carrying cavity, an assembly ring is arranged on the peripheral wall of the side wall electrode, and the side wall electrode is in hole-shaft fit with the packaging shell through the assembly ring; the electrode sealing piece is connected with the transparent electrode and the side wall electrode; the light-transmitting cover is bonded with the side wall electrode and covers the liquid carrying cavity; the first electrical connecting piece is connected with the side wall electrode; the second electrical connecting piece is connected with the transparent electrode; and the packaging clamping ring is used for centering and clamping and is in threaded connection with the packaging shell. According to the electrowetting liquid lens, the assembly coaxiality can be guaranteed and improved, rapid assembly and iteration can be realized, the zoom mechanism research efficiency can be improved, the cost is low, the reliability is high, and the stability is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrowetting liquid lens, in particular to an electrowetting liquid lens, a preparation method of the electrowetting liquid lens and a preparation system of the electrowetting liquid lens. BACKGROUND

[0002] The electrowetting liquid lens is a mechanical motion-free zoom optical element based on the electrowetting effect. By changing the voltage applied to the interface between the conductive liquid and the insulating liquid, the interface curvature can be continuously and quickly adjusted to achieve focal length adjustment. Due to its compact structure, fast response and low power consumption, the electrowetting liquid lens has a wide application prospect in the fields of machine vision, microscopic imaging, endoscopic medical treatment and consumer electronics.

[0003] At present, the mainstream method for realizing the preparation of the electrowetting liquid lens relies on a metal thin-wall stamping forming process. The process forms a liquid carrying cavity by stamping and bending a metal sheet multiple times through a special mold, and then performs packaging through a crimping process similar to a button cell. The above method has the following problems: first, the mold is highly specialized. Once the cavity structure (such as aperture, taper, shape) needs to be adjusted, the entire set of molds must be redesigned and manufactured, resulting in a long research and development cycle and high iteration cost; second, the process is complex and requires high equipment, especially when making large-aperture (centimeter-level) lenses, the yield and consistency are difficult to guarantee; third, the assembly process lacks systematic coaxiality control means and often relies on general fixtures, which can easily cause alignment deviation between the internal optical components and the shell, thereby introducing aberration and affecting the imaging quality and system integration accuracy.

[0004] Some schemes attempt to use 3D printing technology to manufacture the lens shell. However, the conventional 3D printed shell is a plastic piece that is easily deformed by heat and has high flexibility, making it difficult to ensure the long-term coaxial stability of the lens in the optical system, thereby causing reduced image quality, inaccurate measurement and difficult system adjustment. At the same time, its processing precision is lower than that of CNC machining, making it difficult to ensure that the optical surface (such as the liquid-liquid interface meniscus) and the shell form a good coaxial fit, and due to the large tolerance, the lens is prone to misalignment and difficult to assemble when assembled into a standard optical barrel, affecting the reliability and system compatibility of the product. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides an electrowetting liquid lens which can guarantee and improve the assembly coaxiality, and by replacing the side wall electrode of the inner wall, the lens can be quickly assembled and iterated, and can be quickly adapted and personalized to the optical system and related experimental test instruments, improving the efficiency of zoom mechanism research, with low cost, high reliability and good stability.

[0006] The application further provides a preparation method of the electrowetting liquid lens.

[0007] The application further provides a preparation system of the electrowetting liquid lens.

[0008] The electrowetting liquid lens according to the first aspect of the application comprises: a cylindrical packaging shell, the packaging shell has a cylindrical packaging cavity, the upper end of the packaging cavity is open to form a circular packaging opening, the lower end of the packaging shell is provided with a circular perspective opening in communication with the packaging cavity, and the side wall of the packaging shell is provided with a delivery groove in communication with the packaging cavity and penetrating through the upper end surface of the packaging shell; a cylindrical lens group, the lens group is arranged in the packaging cavity and comprises: an annular transparent electrode arranged on the bottom wall of the packaging cavity; a cylindrical side wall electrode having a cavity penetrating through the side wall electrode, the lower end of the cavity being capped by the transparent electrode to define a carrier liquid cavity, the lower part of the carrier liquid cavity being filled with a polar liquid and the upper part being filled with a non-polar liquid, the lower end surface of the side wall electrode being provided with a sealing groove with an open outer edge, and the outer peripheral wall of the side wall electrode being provided with an annular assembly ring extending radially outward, the side wall electrode being in hole shaft cooperation with the inner peripheral surface of the packaging shell through the outer peripheral surface of the assembly ring; an electrode sealing piece arranged in the sealing groove and connected with the transparent electrode and the side wall electrode; a light-transmitting cover bonded with the side wall electrode and capping the upper end surface of the carrier liquid cavity; a first electrical connecting piece connected with the side wall electrode and extending out of the packaging shell through the delivery groove, and a second electrical connecting piece connected with the transparent electrode and extending out of the packaging shell through the delivery groove; a packaging clamping ring for centering and clamping, the packaging clamping ring is arranged in the packaging cavity and is threadedly connected with the packaging shell; and a flexible protective gasket, the flexible protective gasket is sleeved on the side wall electrode and is pressed against the upper end surface of the assembly ring by the packaging clamping ring.

[0009] The electrowetting liquid lens according to the embodiment of the application can guarantee and improve the assembly coaxiality, and can realize rapid assembly and rapid iteration by only replacing the side wall electrode of the inner wall, can quickly adapt and personalize the optical system and related experimental test instruments, and improve the zoom mechanism research efficiency, and has low cost, high reliability and good stability.

[0010] In addition, the electrowetting liquid lens according to the embodiment of the application has the following additional technical features: According to some examples of the application, the coaxiality of the packaging shell and the lens group is less than 0.1 mm.

[0011] According to some examples of the application, the inner wall of the carrier liquid cavity is inclined from top to bottom towards the direction close to the central axis of the lens group.

[0012] According to some examples of the present application, the upper end surface of the sidewall electrode is provided with a plurality of stepped surfaces, the light-transmitting cover is in clearance fit with the inner peripheral wall of the sidewall electrode, and the light-transmitting cover and the sidewall electrode are connected by an adhesive or potting agent filled in the clearance.

[0013] In some specific examples of the present application, the plurality of stepped surfaces comprises a first step surface, a second step surface and a third step surface connected from bottom to top, the lower end surface of the light-transmitting cover is in fit with the first step surface, the axial height of the second step surface is greater than half of the axial height of the light-transmitting cover, and the third step surface is below the upper end surface of the light-transmitting cover.

[0014] According to the preparation method of the electro-wetting liquid lens according to the second aspect of the present application, the electro-wetting liquid lens is the electro-wetting liquid lens according to the first aspect of the present application, and the preparation method comprises: The sidewall of the carrier liquid cavity is plated with a dielectric layer by using a chemical vapor deposition device, a hydrophobic layer is plated on the dielectric layer, the outer peripheral surface of the sidewall electrode is radially clamped and the axial direction of the sidewall electrode is kept vertical by using a pulling film coating machine, and the pulling film coating machine is placed in a vacuum oven, and the drying temperature is lower than the unstable temperature and the decomposition temperature of the dielectric layer; The transparent electrode is plated with an ITO conductive film by using a magnetron sputtering device; The sidewall electrode is clamped into an upper mounting tool, and the transparent electrode is clamped into a lower mounting tool, and centering is performed; The electrode sealing member is glued by using a glue spreading machine, the electrode sealing member is clamped into the lower end surface of the sidewall electrode, and the electrode sealing member is fixed by being pressed downward by using an electrode bonding clamp, and the carrier liquid cavity is formed after solidification; The polar liquid after negative pressure defoaming is injected into the lower part of the carrier liquid cavity by using a pipette; The carrier liquid cavity is placed in a liquid immersion packaging clamp body and immersed in a container containing non-polar liquid after negative pressure defoaming, the light-transmitting cover is placed on the upper end surface of the sidewall electrode, the lens set is clamped and fixed by using a threaded pressing part, and then taken out, an adhesive or potting agent is filled between the light-transmitting cover and the upper end surface of the sidewall electrode, and the surface of the lens set is cleaned after solidification; The first electrical connecting member is bonded to the sidewall electrode by using two-component conductive copper-based or silver-based glue, and the second electrical connecting member is bonded to the transparent electrode, and the lens set is placed in the packaging cavity after solidification, and the assembly ring is matched with the hole shaft of the packaging shell; The flexible protective gasket is pressed tightly on the upper end surface of the assembly ring by using the packaging clasp ring.

[0015] The method for preparing an electrowetting liquid lens according to an embodiment of the present invention can ensure and improve the coaxiality of the assembly, and can achieve rapid assembly and rapid iteration by simply replacing the sidewall electrodes of the inner wall. It can quickly adapt to and personalize optical systems and related experimental testing equipment, improve the efficiency of zoom mechanism research, and has low cost, high reliability and good stability.

[0016] In addition, the method for preparing an electrowetting liquid lens according to an embodiment of the present invention also has the following additional technical features: According to some embodiments of the present invention, the dielectric layer is made of pyrene C and has a thickness of 1 μm – 4 μm.

[0017] According to some embodiments of the present invention, the hydrophobic layer is made of Teflon AF 1601, the immersion speed of the dip coating is 10000 μm / s – 20000 μm / s, the time is 2 s, the pull-out speed is 10000 μm / s – 20000 μm / s, the number of cycles is 2, the drying time is 20 min, and the thickness of the hydrophobic layer is 100 nm – 500 nm.

[0018] According to some embodiments of the present invention, the thickness of the ITO conductive film is 100 nm – 200 nm, the transmittance is greater than 85%, and the surface resistance is less than 20 Ω.

[0019] According to a third aspect of the present invention, a fabrication system for an electrowetting liquid lens, wherein the electrowetting liquid lens is an electrowetting liquid lens according to a first aspect of the present invention, the system comprises: a vacuum oven; a chemical vapor deposition apparatus for depositing a dielectric layer on the sidewall of the liquid-carrying chamber and depositing a hydrophobic layer on the dielectric layer; a dip-coating machine for radially clamping the outer peripheral surface of the sidewall electrode and keeping the axial direction of the sidewall electrode vertical, and placing it in the vacuum oven, wherein the drying temperature is lower than the instability temperature and decomposition temperature of the dielectric layer; a magnetron sputtering apparatus for depositing an ITO conductive thin film on the transparent electrode; and an upper fixture. The system includes: an upper fixture for centering the sidewall electrode and a lower fixture for centering the transparent electrode; a spin coater for dispensing adhesive onto the electrode seal; an electrode bonding clamp for pressing and fixing the sidewall electrode, the electrode seal, and the transparent electrode; a pipette for injecting the negative-pressure defoamed polar liquid into the lower part of the liquid-carrying chamber; and a liquid immersion encapsulation clamp for placing the liquid-carrying chamber and immersing it entirely in a container filled with a negative-pressure defoamed non-polar liquid. The liquid immersion encapsulation clamp is equipped with a threaded pressing member for clamping and fixing the lens assembly before removal.

[0020] The electrowetting liquid lens fabrication system according to embodiments of the present invention, utilizing the electrowetting liquid lens as described above, can ensure and improve assembly coaxiality, and can achieve rapid assembly and rapid iteration by simply replacing the sidewall electrodes of the inner wall. It can quickly adapt to and personalize optical systems and related experimental testing equipment, improve the efficiency of zoom mechanism research, and has low cost, high reliability and good stability. Attached Figure Description

[0021] Figure 1 This is a perspective view of an electrowetting liquid lens according to an embodiment of the present invention; Figure 2 This is an axial exploded view of an electrowetting liquid lens according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an electrowetting liquid lens according to an embodiment of the present invention; Figure 4 It is along Figure 3 Sectional view of line II in the middle; Figure 5 yes Figure 4 Enlarged view of part A shown in the center circle; Figure 6 yes Figure 4 Enlarged view of section B shown in the center circle; Figure 7 yes Figure 4 Enlarged view of section C, shown in the center circle; Figure 8 This is a schematic diagram of the driving zoom of an electrowetting liquid lens according to an embodiment of the present invention. Line segments ①②③ in the figure indicate the meniscus shape under different conditions. Figure 9 This is a perspective view of the sidewall electrode according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the sidewall electrode structure according to an embodiment of the present invention; Figure 11 This is a structural diagram of the sidewall electrode according to an embodiment of the present invention; Figure 12 It is along Figure 11 Sectional view of line II-II in the middle; Figure 13 This is a schematic diagram of the fabrication process of an electrowetting liquid lens according to an embodiment of the present invention; Figure 14 This is a schematic diagram of the liquid immersion packaging of an electrowetting liquid lens according to an embodiment of the present invention.

[0022] Figure label: Electrowetting liquid lens 10, Encapsulation housing 100, viewing port 101, and channel 102. Lens assembly 200, transparent electrode 210, ITO conductive film 211, sidewall electrode 220, polar liquid 221, non-polar liquid 222, dielectric layer 223, hydrophobic layer 224, assembly ring 225, sealing groove 226, first mesa 227, second mesa 228, third mesa 229, electrode seal 230, light-transmitting cover 240. First electrical connector 300, second electrical connector 400, sealing retaining ring 500, flexible protective washer 600. Upper fixture 20, lower fixture 30, electrode bonding fixture 40, liquid immersion encapsulation fixture 50, threaded pressing component 51. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] The electrowetting liquid lens 10 according to a first aspect of the present invention will now be described with reference to the accompanying drawings.

[0025] like Figures 1-14 As shown, the electrowetting liquid lens 10 according to an embodiment of the present invention includes: a cylindrical encapsulation shell 100, a cylindrical lens assembly 200, a first electrical connector 300 and a second electrical connector 400, an encapsulation retaining ring 500 for centering and clamping, and a flexible protective gasket 600.

[0026] Specifically, the encapsulation housing 100 has a cylindrical encapsulation cavity, with the upper end of the cavity open to form a circular encapsulation opening. The lower end of the encapsulation housing 100 has a circular viewing opening 101 communicating with the encapsulation cavity. The sidewall of the encapsulation housing 100 has a transfer groove 102, which communicates with the encapsulation cavity and extends through the upper end face of the encapsulation housing 100. For example, the encapsulation housing 100 can be made of aluminum alloy to achieve a lightweight design. As the housing of an optical element needs to suppress stray light and ensure the overall insulation of the lens, a black satin anodizing process can be selected for the surface treatment of the encapsulation housing 100. To facilitate rapid deployment in optical applications and scientific research, the outer diameter of the encapsulation housing 100 can be SM1 (25.4mm nominal diameter) or other thread specifications that fit the international standard lens barrel diameter series, allowing for rapid stacking with other optical components to build a coaxial optical system for testing and application.

[0027] Lens assembly 200 is disposed within the encapsulation cavity. Lens assembly 200 includes: an annular transparent electrode 210, a cylindrical sidewall electrode 220, an electrode seal 230, and a light-transmitting cover 240. The transparent electrode 210 is disposed on the bottom wall of the encapsulation cavity and can be a borosilicate glass component, a quartz glass component, or other transparent components. The surface of the transparent electrode 210 in contact with the liquid can be coated with an ITO (Indium Tin Oxide) conductive film. To achieve good photoelectric performance, it must have high transmittance and low surface resistance. Specifically, the thickness of this coating is 100 nm – 200 nm, the transmittance is greater than 85%, and its surface resistance is less than 20 Ω.

[0028] The sidewall electrode 220 can be made of aluminum or other metals with good conductivity and machinability. The sidewall electrode 220 has a through cavity, and the transparent electrode 210 seals the lower end of the cavity to define a liquid-carrying chamber. The lower part of the liquid-carrying chamber is filled with a polar liquid 221, and the upper part is filled with a non-polar liquid 222. The solvent for the polar liquid 221 can be one or more of water-based or non-water-based liquids (such as alcohol solvents like ethanol). The water-based solution can be a salt solution with added electrolytes such as KCl or NaCl. The aqueous solution can be configured and controlled by combining the aperture of the lens group 200 and the viscosity of the non-polar liquid 222. The viscosity of the polar liquid 221 (i.e., the conductive liquid) can be adjusted by adding non-ionic, water-soluble polymers such as glycerol, which are miscible with water; for example, its dynamic viscosity can be 1 mPa. s – 50 mPa s. Non-aqueous solutions can be formed by adding electrolytes to alcohol solvents. In anhydrous systems, the liquid conductive phase no longer generates hydrogen ions and hydroxide ions, thus preventing hydrolysis and further improving the service life of lens group 200.

[0029] The nonpolar liquid 222 can be silicone oil or other organic solvents immiscible with the prepared polar liquid 221. High-refractive-index silicone oil (modified systems such as phenyl, mercaptoaryl, etc.) is preferred, thereby creating a high refractive index difference with the polar liquid 221 and achieving a wider zoom range. The viscosity of the nonpolar liquid 222 affects the dynamic response characteristics of the lens group 200. To obtain a lower response time, nonpolar liquid 222 with different viscosities can be selected based on the aperture of the lens group 200 and the viscosity of the polar liquid 221. For example, the dynamic viscosity of the nonpolar liquid 222 can be 50 mPa. s – 2000 mPa s.

[0030] Since the three-phase contact lines of the electrowetting liquid lens 10 slide on the inner wall surface of the sidewall electrode 220, and the inner wall surface of the sidewall electrode 220 needs to be coated to form a dielectric layer 223 and a hydrophobic layer 224, excessively low roughness will reduce the adhesion of the dielectric layer 223 and the hydrophobic layer 224 to a certain extent. Therefore, the roughness of the inner wall surface of the sidewall electrode 220 is Ra 0.1 – Ra0.5. The inner wall diameter of the sidewall electrode 220 can be 6 mm ~ 16 mm, and the tilt angle of the inner wall surface of the sidewall electrode 220 (the angle between it and the axis of the lens group 200) can be 30°, 45°, 60°, etc. This tilt angle can control the range of optical power variation, and at the same time, make the part with higher quality of the meniscus center surface formed by the polar liquid 221 and the non-polar liquid 222 within the same aperture range, thereby improving the imaging quality. Other liquid-carrying chamber configurations, such as one or more combinations of conical, spherical, and multi-step cylindrical chambers, can be quickly obtained through CNC machining. Only the corresponding sidewall electrodes 220 need to be machined for replacement without replacing other parts. Figure 4 and Figure 8 The inner wall of the liquid-carrying cavity slopes from top to bottom toward the central axis of the lens group 200, meaning the liquid-carrying cavity is a cone with an upper diameter larger than a lower diameter.

[0031] The dielectric layer 223 is made of one or more dielectric materials such as parylene (Pyrelin), preferably Pyrelin C powder as the coating material for the dielectric layer 223. A chemical vapor deposition (CVD) process under high vacuum conditions is used, with a preferred coating thickness of 1 μm to 4 μm, thus achieving a high breakdown voltage. Simultaneously, depending on the roughness requirements of the inner wall substrate of the sidewall electrode 220, the coating roughness is Ra 0.15 – Ra 0.5. The hydrophobic layer 224 includes at least one or more fluoropolymers such as Teflon, preferably a low molecular weight solution of Teflon AF 1601 (fluorinated dioxane-tetrafluoroethylene copolymer) as the coating material for the hydrophobic layer 224. On the substrate already coated with the Pyrelin C dielectric layer 223, the coating thickness can be 100 nm to 500 nm.

[0032] Because different axes can transform the rotational symmetry of an optical system into asymmetry, disrupting the original rotationally symmetrical wavefront, and introducing various asymmetric aberrations, leading to reduced image quality, measurement inaccuracies, and difficulties in system assembly and adjustment, the outer peripheral wall of the sidewall electrode 220 is provided with an annular mounting ring extending radially outward. The outer peripheral surface of the sidewall electrode 220 is fitted with the inner peripheral surface of the package housing 100 through a hole-axis engagement to ensure that the inner wall surface of the sidewall electrode 220 and the sidewall surface of the package housing 100 maintain a certain coaxiality. For example, the coaxiality between the package housing 100 and the lens group 200 is less than 0.1 mm.

[0033] The lower end face of the sidewall electrode 220 is provided with an open sealing groove 226. An electrode seal 230 is disposed in the sealing groove 226, connecting the transparent electrode 210 and the sidewall electrode 220. The electrode seal 230 can be a rubber part (such as fluororubber or fluorosilicone rubber) or a plastic part with good thermal stability, corrosion resistance, and resistance to polar solvents. The cross-section of the electrode seal 230 can be "L-shaped" or "U-shaped," effectively increasing the contact area with the transparent electrode 210 and the sidewall electrode 220. The upper end face of the electrode seal 230 is nested and bonded to the lower end face of the sidewall electrode 220 with adhesive, and the lower end face of the electrode seal 230 is bonded to the transparent electrode 210 with adhesive. The curing process of the adhesive is achieved by centering and fixing with the electrode bonding clamp 40. Both the electrode seal 230 and the adhesive are insulating components, thus possessing the ability to isolate the transparent electrode 210 and the sidewall electrode 220 and prevent them from conducting to each other. This ensures the airtightness of the lower end face of the liquid-carrying chamber.

[0034] The light-transmitting cover 240 is bonded to the sidewall electrode 220 and seals the upper end face of the liquid-carrying cavity. The light-transmitting cover 240 can be made of borosilicate glass or quartz glass. To ensure high transmittance, an anti-reflective coating can be applied to the light-transmitting cover 240.

[0035] The first electrical connector 300 is connected to the sidewall electrode 220 and extends out of the encapsulation shell 100 through the transfer groove 102. The second electrical connector 400 is connected to the transparent electrode 210 and extends out of the encapsulation shell 100 through the transfer groove 102. The first electrical connector 300 and the second electrical connector 400 can be electrically connected to the drive circuit control board using a customized FPC flexible flat cable. The two electrodes of the FPC flexible flat cable are connected to the lower end face of the mounting ring and the upper end face (the end face where the ITO conductive film is located) of the transparent electrode 210, respectively. This electrical connection method uses a two-component copper / silver conductive adhesive as the adhesive. At the same time, the adhesive must have strong adhesion and good conductivity to ensure the electrical connection between the flat cable and the sidewall electrode 220 and the transparent electrode 210. For applications involving precision drive power supply equipment in laboratories, a fork-shaped copper foil can be used to conductively bond with the sidewall electrode 220 and the transparent electrode 210. The sidewall electrode 220 and the transparent electrode 210 extend from the copper sheet protrusions through the upper and lower openings of the encapsulation shell 100, which can be adapted to power supply clamps for conventional power supplies and other equipment, such as alligator clips for testing.

[0036] A retaining ring 500 is disposed within the encapsulation cavity and is threadedly connected to the encapsulation housing 100. The retaining ring 500 is tightened by inserting a universal optical retaining ring wrench into the retaining ring groove. A certain margin is allowed in the thread length between the encapsulation housing 100 and the retaining ring 500 to accommodate lens assemblies 200 with different inner cavity heights and diameters. The retaining ring 500 can be made of lightweight aluminum alloy. The encapsulation housing 100, in conjunction with the spiral retaining ring 500, applies a reasonable preload to the lens assembly 200, further preventing axial adhesion of the lens assembly 200 and stress relaxation of some elastic components, thereby ensuring the stability of the electrowetting liquid lens 10 in use and extending its lifespan.

[0037] The flexible protective gasket 600 can be made of silicone, rubber, foam, or other composite materials. Preferably, the flexible protective gasket 600 is made of high-density silicone (HCR). The flexible protective gasket 600 is located on the sidewall electrode 220 and is pressed against the upper end face of the assembly ring by the encapsulation retaining ring 500. Thus, when the encapsulation retaining ring 500 centers and presses the lens assembly 200, the flexible protective gasket 600 can protect the lens assembly 200 from surface damage due to preload. Simultaneously, during the use of the electrowetting liquid lens 10, there may be temperature changes and vibration / impact, causing pressure changes within the liquid-carrying chamber, resulting in air bubbles that affect the airtightness and performance of the lens assembly 200. The flexible protective gasket 600 can also, to a certain extent, reduce the range of external and internal pressure changes, reducing the possibility of air bubbles generated due to vibration / impact and internal stress changes.

[0038] Therefore, the coaxial design of the encapsulation shell 100 and the lens group 200 ensures a high degree of coaxiality between the meniscus at the dual-liquid interface and the mating surfaces of the assembly ring and the encapsulation shell 100. This allows for rapid integration with other optical components along with a standardized lens barrel to form an optical system, enabling quick machine vision applications. For different liquid-carrying cavity configurations, only the corresponding sidewall electrodes 220 and a few easily manufactured parts (such as electrode bonding parts) need to be fabricated for replacement without replacing other components. From an experimental perspective, lens groups 200 with different internal cavity structures can be quickly assembled and, combined with the encapsulation shell 100, can be directly integrated into a coaxial system for testing and application. With the dimensions of the glass components, elastic components, and encapsulation shell 100 remaining largely unchanged, rapid iteration and immediate use can be achieved by changing the inner wall diameter, taper, and configuration of the sidewall electrodes 220. By using the encapsulation shell 100 and the encapsulation retainer 500 to clamp the lens group 200, loosening problems caused by changes in the elastic components and internal stress within the lens group 200 can be effectively prevented, thereby improving airtightness and lifespan.

[0039] The electrowetting liquid lens 10 according to the present invention can ensure and improve the assembly coaxiality, and can achieve rapid assembly and rapid iteration by simply replacing the side wall electrode 220 of the inner wall. It can quickly adapt to and personalize optical systems and related experimental testing equipment, improve the efficiency of zoom mechanism research, and has low cost, high reliability and good stability.

[0040] According to some examples of the present invention, such as Figure 7 , Figure 9 and Figure 12 As shown, the upper end face of the sidewall electrode 220 is provided with multiple stepped surfaces. The light-transmitting cover 240 is fitted with the inner peripheral wall of the sidewall electrode 220 with a gap. The light-transmitting cover 240 and the sidewall electrode 220 are connected by adhesive or potting compound filled in the gap, so as to achieve the airtightness of the encapsulation cavity and the electrical insulation between the two electrodes.

[0041] In some specific examples of the present invention, such as Figure 7 and Figure 12 As shown, the multiple stepped surfaces include a first platform 227, a second platform 228, and a third platform 229 connected from bottom to top. The lower end face of the light-transmitting cover 240 is attached to the first platform 227. The axial height of the second platform 228 is greater than half the axial height of the light-transmitting cover 240, serving as an initial limiting function for the light-transmitting cover 240 during the liquid immersion encapsulation process. The third platform 229 is located below the upper end face of the light-transmitting cover 240, preventing adhesive or potting compound from remaining in the light-transmitting area during the curing process.

[0042] A method for preparing an electrowetting liquid lens 10 according to a second aspect embodiment of the present invention includes: A dielectric layer 223 is deposited on the sidewall of the liquid-carrying cavity using a chemical vapor deposition apparatus. A hydrophobic layer 224 is then deposited on the dielectric layer 223. The outer peripheral surface of the sidewall electrode 220 is radially clamped using a dip-coating machine while keeping the axial direction of the sidewall electrode 220 vertical. The electrode is then placed in a vacuum oven and dried at a temperature lower than the instability temperature and decomposition temperature of the dielectric layer 223. For example, the dip-coating immersion rate is 10000 μm / s – 20000 μm / s for 2 s, the dip-coating speed is 10000 μm / s – 20000 μm / s, the number of cycles is 2, the drying time is 20 min, and the thickness of the hydrophobic layer 224 is 100 nm – 500 nm. ITO conductive film was deposited on transparent electrode 210 using a magnetron sputtering device; The sidewall electrode 220 is inserted into the upper fixture 20 and the transparent electrode 210 is inserted into the lower fixture 30 for centering. A glue applicator is used to apply glue to the electrode seal 230, which is then snapped into the lower end face of the sidewall electrode 220. The electrode bonding fixture 40 is used to press and fix it in place. After curing, a liquid-carrying cavity is formed. If the dimensions of the sidewall electrode 220 and the transparent electrode 210 change, only the corresponding upper fixture 20 or lower fixture 30 needs to be replaced during the process, which improves production efficiency and iteration speed. A negative pressure defoaming polar liquid 221 was injected into the lower part of the liquid-carrying chamber using a pipette. The liquid-carrying cavity is placed into the liquid immersion packaging fixture 50 and the whole is immersed in a container containing a non-polar liquid 222 after negative pressure defoaming. Place the light-transmitting cover 240 on the stepped surface of the side wall electrode 220, clamp and fix the lens group 200 with the threaded pressing part 51, and then remove it. Fill the gap between the light-transmitting cover 240 and the side wall electrode 220 with AB glue or potting compound, and clean the surface of the lens group 200 after curing. The first electrical connector 300 is bonded to the side wall electrode 220 and the second electrical connector 400 is bonded to the transparent electrode 210 using a two-component conductive copper or silver adhesive. After curing, the lens assembly 200 is placed in the encapsulation cavity and the assembly ring is engaged with the hole shaft of the encapsulation shell 100. The flexible protective washer 600 is pressed onto the upper end face of the assembly ring using a sealing retaining ring 500.

[0043] like Figures 13-14 As shown, the fabrication system for an electrowetting liquid lens 10 according to a second aspect embodiment of the present invention includes: a vacuum oven, a chemical vapor deposition apparatus, a dip-coating machine, a magnetron sputtering apparatus, an upper fixture 20 and a lower fixture 30, a spin coater, an electrode bonding fixture 40, a pipette, and a liquid immersion encapsulation fixture 50.

[0044] Specifically, a chemical vapor deposition (CVD) apparatus is used to deposit a dielectric layer 223 on the sidewalls of the liquid-carrying chamber, and a hydrophobic layer 224 is deposited on the dielectric layer 223. A dip-coating machine is used to radially clamp the outer peripheral surface of the sidewall electrode 220 while keeping the axial direction of the sidewall electrode 220 vertical, and place it in a vacuum oven to dry at a temperature lower than the instability temperature and decomposition temperature of the dielectric layer 223. A magnetron sputtering apparatus is used to deposit an ITO conductive film on the transparent electrode 210. An upper fixture 20 is used to center the sidewall electrode 220, and a lower fixture 30 is used to center the transparent electrode 210. A spin coater is used to apply adhesive to the electrode seal 230. An electrode bonding fixture 40 is used to press down and fix the sidewall electrode 220, the electrode seal 230, and the transparent electrode 210. A pipette is used to inject a negative-pressure defoamed polar liquid 221 into the lower part of the liquid-carrying chamber. The liquid immersion packaging fixture 50 is used to place the liquid-carrying cavity and immerse it entirely in a container containing a non-polar liquid 222 after negative pressure defoaming. The liquid immersion packaging fixture 50 is provided with a threaded pressing member 51, which is used to clamp and fix the lens assembly 200 and then remove it.

[0045] The fabrication system of the electrowetting liquid lens 10 according to the present invention can ensure and improve the assembly coaxiality by using the electrowetting liquid lens 10 as described above. It can also achieve rapid assembly and rapid iteration by simply replacing the side wall electrode 220 of the inner wall. It can quickly adapt to and personalize optical systems and related experimental testing equipment, improve the efficiency of zoom mechanism research, and has low cost, high reliability and good stability.

[0046] Other configurations and operations of the fabrication system for the electrowetting liquid lens 10 according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0047] In the description of this invention, it should be understood that the terms "center", "width", "thickness", "upper", "lower", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0049] In the description of this invention, "first feature" and "second feature" may include one or more of the features. "Above" or "below" the second feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. "Above," "above," and "over" the second feature include the first feature being directly above or diagonally above the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature.

[0050] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can also refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "specific embodiment," "example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0052] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A liquid-wetting lens, characterized in that, include: A cylindrical encapsulation housing has a cylindrical encapsulation cavity, the upper end of which is open to form a circular encapsulation opening, and the lower end of which is provided with a circular viewing opening communicating with the encapsulation cavity. The side wall of the encapsulation housing is provided with a transfer groove, which communicates with the encapsulation cavity and penetrates the upper end face of the encapsulation housing. A cylindrical lens assembly, wherein the lens assembly is disposed within the encapsulation cavity and includes: An annular transparent electrode, wherein the transparent electrode is disposed on the bottom wall of the encapsulation cavity; A cylindrical sidewall electrode has a through cavity. A transparent electrode covers the lower end of the cavity to define a liquid-carrying cavity. The lower part of the liquid-carrying cavity is filled with a polar liquid and the upper part is filled with a non-polar liquid. The lower end face of the sidewall electrode is provided with a sealing groove with an open outer edge. The outer peripheral wall of the sidewall electrode is provided with an annular assembly ring extending radially outward. The sidewall electrode is engaged with the inner peripheral surface of the encapsulation shell through a hole-shaft connection via the outer peripheral surface of the assembly ring. An electrode seal is disposed in the sealing groove and connects the transparent electrode and the sidewall electrode; A light-transmitting cover is bonded to the sidewall electrode and seals the upper surface of the liquid-carrying cavity; A first electrical connector and a second electrical connector, wherein the first electrical connector is connected to the sidewall electrode and extends out of the encapsulation housing through the clearance groove, and the second electrical connector is connected to the transparent electrode and extends out of the encapsulation housing through the clearance groove; A sealing retaining ring for centering and clamping, wherein the sealing retaining ring is disposed in the sealing cavity and threadedly connected to the sealing shell; A flexible protective washer is sleeved on the sidewall electrode and pressed against the upper end face of the assembly ring by the encapsulation retainer.

2. The electrowetting liquid lens according to claim 1, characterized in that, The coaxiality between the encapsulation shell and the lens assembly is less than 0.1 mm.

3. The electrowetting liquid lens according to claim 1, characterized in that, The inner wall of the liquid-carrying cavity slopes from top to bottom toward the central axis of the lens group.

4. The electrowetting liquid lens according to claim 1, characterized in that, The upper surface of the sidewall electrode is provided with multiple stepped surfaces. The light-transmitting cover is fitted with the inner peripheral wall of the sidewall electrode with a gap. The light-transmitting cover and the sidewall electrode are connected by an adhesive or potting compound filled in the gap.

5. The electrowetting liquid lens according to claim 4, characterized in that, The plurality of stepped surfaces include a first platform, a second platform, and a third platform connected from bottom to top. The lower end surface of the light-transmitting cover is in contact with the first platform. The axial height of the second platform is greater than half of the axial height of the light-transmitting cover. The third platform is located below the upper end surface of the light-transmitting cover.

6. A method for preparing an electrowetting liquid lens, characterized in that, The electrowetting liquid lens is an electrowetting liquid lens according to any one of claims 1-5, and the method includes: A dielectric layer is deposited on the sidewall of the liquid-carrying cavity using a chemical vapor deposition apparatus, and a hydrophobic layer is deposited on the dielectric layer. The outer peripheral surface of the sidewall electrode is radially clamped using a dip-coating machine while keeping the axial direction of the sidewall electrode vertical, and the electrode is placed in a vacuum oven. The drying temperature is lower than the instability temperature and decomposition temperature of the dielectric layer. The transparent electrode is deposited with an ITO conductive film using a magnetron sputtering device; The sidewall electrode is inserted into the upper fixture and the transparent electrode is inserted into the lower fixture for centering. The electrode sealant is applied using a glue applicator, and then inserted into the lower end face of the sidewall electrode. The sealant is then pressed down and fixed using an electrode bonding clamp, and after curing, the liquid-carrying cavity is formed. The polar liquid, after being defoamed under negative pressure, is injected into the lower part of the liquid-carrying chamber using a pipette; The liquid-carrying cavity is placed into the liquid immersion packaging fixture and the whole is immersed in a container of non-polar liquid after negative pressure defoaming. Place the light-transmitting cover on the upper end face of the side wall electrode, clamp and fix the lens group with a threaded pressing member, and then remove it. Fill the space between the light-transmitting cover and the upper end face of the side wall electrode with adhesive or potting compound, and clean the surface of the lens group after curing. The first electrical connector is bonded to the sidewall electrode and the second electrical connector is bonded to the transparent electrode using a two-component conductive copper-based or silver-based adhesive. After curing, the lens assembly is placed in the encapsulation cavity and the assembly ring is engaged with the hole shaft of the encapsulation shell. The flexible protective washer is pressed against the upper end face of the assembly ring using the encapsulation retaining ring.

7. The method for preparing an electrowetting liquid lens according to claim 6, characterized in that, The dielectric layer is made of pyrene C and has a thickness of 1 μm – 4 μm.

8. The method for preparing an electrowetting liquid lens according to claim 6, characterized in that, The hydrophobic layer is made of Teflon AF 1601. The immersion speed of the dip coating is 10000 μm / s – 20000 μm / s for 2 s, the pull-out speed is 10000 μm / s – 20000 μm / s, the number of cycles is 2, the drying time is 20 min, and the thickness of the hydrophobic layer is 100 nm – 500 nm.

9. The method for preparing an electrowetting liquid lens according to claim 6, characterized in that, The ITO conductive film has a thickness of 100 nm – 200 nm, a transmittance greater than 85%, and a surface resistance less than 20 Ω.

10. A system for fabricating an electrowetting liquid lens, characterized in that, The electrowetting liquid lens is an electrowetting liquid lens according to any one of claims 1-5, and the system comprises: Vacuum drying oven; A chemical vapor deposition apparatus, wherein the chemical vapor deposition apparatus is used to deposit a dielectric layer on the sidewall of the liquid-carrying chamber and to deposit a hydrophobic layer on the dielectric layer; A dip-coating machine is used to radially clamp the outer peripheral surface of the sidewall electrode and keep the axial direction of the sidewall electrode in the vertical direction, and place it in the vacuum oven, where the drying temperature is lower than the unstable temperature and decomposition temperature of the dielectric layer. A magnetron sputtering apparatus, wherein the magnetron sputtering apparatus is used to deposit an ITO conductive thin film onto the transparent electrode; An upper fixture and a lower fixture, wherein the upper fixture is used to center the sidewall electrode and the lower fixture is used to center the transparent electrode; A glue applicator, used for applying glue to the electrode sealant; An electrode bonding fixture is used to press down and fix the sidewall electrode, the electrode seal, and the transparent electrode. A pipette, used to inject the polar liquid after negative pressure defoaming into the lower part of the liquid-carrying chamber; The liquid immersion encapsulation clamp is specifically designed to place the liquid-carrying cavity and immerse it entirely in a container of non-polar liquid after negative pressure defoaming. The liquid immersion encapsulation clamp is provided with a threaded pressing member, which is used to clamp and fix the lens assembly before removing it.

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