An optical waveguide packaging structure and a packaging method thereof, and an augmented reality optical device

Abstract

This application relates to the field of optical technology, and in particular to an optical waveguide packaging structure and packaging method, and augmented reality optical devices. The structure includes a rigid frame and at least two layers of optical waveguides stacked on the rigid frame. A gap layer is provided between adjacent layers of the optical waveguides, and a predetermined angle is formed between adjacent layers. A pressure equalization channel and a buffer cavity are respectively provided in the rigid frame. One end of the pressure equalization channel communicates with the gap layer, and the other end communicates with the buffer cavity. The buffer cavity is connected to the external environment. A barrier unit is provided within the buffer cavity to block water and particulate matter from passing through and to limit the gas exchange rate. This application achieves pressure balance in the gap layer while avoiding the impact on the stability of the predetermined angle of the optical waveguides.

Description

Technical Field

[0001] This application relates to the field of optical technology, and in particular to an optical waveguide packaging structure and packaging method thereof, and augmented reality optical devices. Background Technology

[0002] Currently, optical waveguides are the core optical components of augmented reality glasses, used to transmit the image beam generated by a miniature projection engine to the area in front of the user's eyes, allowing them to see a virtual image superimposed on the real world. A single optical waveguide typically only transmits a single color of light. To achieve full-color display, three waveguides, each transmitting red, green, and blue light respectively, need to be stacked and combined to achieve full-color image display through image merging. To obtain a good image merging effect, a precise preset angle must be maintained between adjacent waveguide layers to compensate for the diffraction and dispersion shift of different colors of light, ensuring that the three-color image precisely overlaps at the user's eye level. Therefore, the multilayer waveguide packaging structure needs to maintain the positional accuracy and angular stability between the waveguide layers during long-term use.

[0003] Multilayer optical waveguide encapsulation typically employs an adhesive to bond adjacent waveguide layers along a closed path on the periphery of the waveguide, fixing them to a rigid frame and forming a sealed gap layer between them. Due to thermal expansion and contraction of the air within this sealed gap layer, a pressure difference arises between the inside and outside of the gap layer. This pressure difference acts on the waveguide surface, potentially causing minute deformations or displacements, thus affecting the stability of the preset angle. To address this pressure difference issue, related technologies employ elastic structures on the rigid frame or elastic adhesive along the adhesive path. Elastic deformation alters the effective volume of the gap layer, thereby regulating the pressure difference between the inside and outside of the gap layer.

[0004] Regarding the aforementioned technologies: When the elastic structure bulges outward due to positive pressure within the gap layer or indents inward due to negative pressure, the boundary constraint conditions on one side of the gap layer change accordingly. This change is transmitted to the surface of the optical waveguide through the gas pressure field within the gap layer, potentially causing a slight displacement or tilt of the optical waveguide, thereby shifting the preset angle between adjacent optical waveguide layers. Especially in practical applications with frequent temperature changes, the elastic structure repeatedly undergoes positive and negative deformations, causing the position and angle of the optical waveguide to fluctuate repeatedly, resulting in unstable image alignment accuracy and affecting the image quality of augmented reality displays.

[0005] Therefore, in the scheme of using an elastic structure for air pressure regulation, while the elastic deformation solves the air pressure problem, it will also introduce the problem of unstable angle, making it difficult for the packaging structure to maintain accurate image display effect over a wide temperature range for a long time. Summary of the Invention

[0006] In order to achieve pressure balance in the gap layer while avoiding the impact on the stability of the preset angle of the optical waveguide, this application provides an optical waveguide packaging structure and packaging method, as well as an augmented reality optical device.

[0007] Firstly, this application provides an optical waveguide packaging structure, which adopts the following technical solution:

[0008] An optical waveguide packaging structure, comprising:

[0009] A rigid frame and at least two layers of optical waveguides stacked on the rigid frame, with a gap layer between adjacent optical waveguides and a preset angle between adjacent optical waveguides;

[0010] The rigid frame is provided with a pressure equalization channel and a buffer cavity. One end of the pressure equalization channel is connected to the gap layer, and the other end of the pressure equalization channel is connected to the buffer cavity. The buffer cavity is connected to the external environment. A barrier unit is provided in the buffer cavity. The barrier unit is located on the communication path between the buffer cavity and the external environment. The barrier unit is used to block water and particulate matter from passing through and to limit the gas exchange rate.

[0011] By adopting the above technical solution, the gap layer can establish a connection with the buffer cavity through the pressure equalization channel, and the buffer cavity is then connected to the external environment. This creates an indirect gas exchange path between the gap layer and the external environment. When the external environmental pressure or temperature changes, the gas inside the gap layer can be slowly released into the buffer cavity through the pressure equalization channel, reducing the pressure difference between the inside and outside of the gap layer and lowering the risk of pressure deformation of the optical waveguide. At the same time, the barrier unit is located at the connection between the buffer cavity and the external environment, which can reduce the possibility of contaminants such as liquid water and particulate matter entering the buffer cavity and gap layer, and make the gas diffusion process smoother. This balances pressure equalization performance and environmental isolation performance, achieving gas pressure balance in the gap layer while avoiding the impact on the stability of the preset angle of the optical waveguide.

[0012] Optionally, a drying layer is provided inside the buffer cavity, and the drying layer is located between the pressure equalization channel and the barrier unit.

[0013] By adopting the above technical solution, after the gas in the external environment enters the buffer cavity through the barrier unit, it can first pass through the drying layer and then enter the pressure equalization channel, thereby reducing the humidity entering the gap layer and reducing the adverse effects of moisture on the optical interface of the optical waveguide.

[0014] Optionally, the pressure equalization channels extend along the sidewalls of the rigid frame and are tortuous, with each gap layer corresponding to at least two pressure equalization channels.

[0015] By adopting the above technical solution, the tortuous channel can extend the gas exchange path and make the pressure change more gradual; each gap layer corresponds to at least two pressure equalization channels, which can improve the redundancy and reliability of the pressure equalization structure.

[0016] Optionally, a protective component is provided on the side of the pressure equalization channel near the gap layer, the protective component being used to prevent adhesive material from entering the pressure equalization channel.

[0017] By adopting the above technical solution, the risk of adhesive material flowing into the pressure equalization channel can be reduced during the encapsulation and adhesive application process, and the blockage of the pressure equalization channel can be avoided, thereby maintaining the stability of the pressure equalization function.

[0018] Optionally, the protective component includes a filter sheet and a baffle protrusion. The filter sheet is disposed at one end of the pressure equalization channel near the gap layer and has multiple micropores. The baffle protrusion is disposed on the inner wall of the rigid frame and surrounds the filter sheet. The height of the baffle protrusion ranges from 0.05mm to 0.3mm, and the baffle protrusion forms a closed or semi-closed baffle boundary on the inner wall of the rigid frame.

[0019] By adopting the above technical solution, the filter can allow gas to pass through while blocking larger particles or flowing adhesive materials; the adhesive-blocking protrusions are arranged around the filter to form local geometric adhesive-blocking boundaries, further reducing the possibility of adhesive materials entering the pressure equalization channel.

[0020] Optionally, an adhesive layer is provided between the optical waveguide and the rigid frame, the adhesive layer and the rigid frame together enclose the sealing boundary of the gap layer, and a buffer layer is provided between the adhesive layer and the optical waveguide, the elastic modulus of the buffer layer being lower than that of the adhesive layer.

[0021] By employing the above technical solution, the adhesive layer is used to fix the optical waveguide to the rigid frame and cooperates with the rigid frame to form the encapsulation boundary surrounding the gap layer. Since the buffer layer is disposed between the adhesive layer and the optical waveguide, and the elastic modulus of the buffer layer is lower than that of the adhesive layer, when external mechanical impact, thermal expansion difference, or assembly stress is applied to the edge area, the buffer layer can preferentially deform, thereby reducing the degree to which stress is directly transmitted to the optical waveguide, thus reducing edge stress concentration and improving the stability of the encapsulation structure.

[0022] Optionally, the barrier unit includes a hydrophobic and breathable membrane with an average pore size of 0.1 μm-1 μm; the minimum cross-sectional area of ​​the pressure equalization channel is smaller than the average cross-sectional area of ​​the buffer cavity.

[0023] By adopting the above technical solution, the average pore size of the hydrophobic and breathable membrane is 0.1μm-1μm, which can effectively block liquid water and fine particulate matter from passing through, while allowing gas molecules to diffuse slowly through, thereby limiting the gas exchange rate. The minimum cross-sectional area of ​​the pressure equalization channel is smaller than the average cross-sectional area of ​​the buffer cavity, so that the pressure equalization channel forms a throttling effect on the gas flow, further reducing the gas exchange rate. At the same time, the buffer cavity has a large volume to provide a better pressure buffering effect.

[0024] Optionally, the gap layer, the pressure equalization channel, and the buffer cavity are all filled with dry inert gas.

[0025] By adopting the above technical solution, the gap layer, the pressure equalization channel and the buffer cavity are all filled with dry inert gas, which can replace the original moisture and active gas components, thereby reducing the internal moisture content and reducing problems such as decreased optical performance and corrosion and aging of components that may be caused by moisture. At the same time, it reduces the adverse effects of the active environment on the structure and further improves the stability of the internal environment.

[0026] Secondly, this application provides a packaging method for an optical waveguide packaging structure, which adopts the following technical solution:

[0027] A packaging method for an optical waveguide packaging structure, used to package the optical waveguide packaging structure described above, includes the following steps:

[0028] A rigid frame is provided, in which the pressure equalization channel and the buffer cavity are formed, and the buffer cavity is connected to the external environment. A barrier unit is provided in the buffer cavity.

[0029] Provide at least two layers of optical waveguides, and adjust the position and angle of the multilayer optical waveguides;

[0030] The optical waveguide, after alignment adjustment, is fixed to the rigid frame, so that a gap layer is formed between two adjacent optical waveguide layers, and the gap layer is connected to the buffer cavity through the equalizing channel.

[0031] By adopting the above technical solution, a voltage equalization and buffer structure can be first established in the rigid frame, and then the alignment and fixation of the optical waveguide can be completed, so that the final packaged multilayer optical waveguide structure has optical positioning capability, voltage equalization capability and environmental isolation capability.

[0032] Thirdly, this application provides an augmented reality optical device, which adopts the following technical solution:

[0033] An augmented reality optical device includes the optical waveguide packaging structure described above.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. By setting a pressure equalization channel and a buffer cavity in the rigid frame, the gap layer can be indirectly connected with the external environment, thereby mitigating the pressure difference between the inside and outside of the gap layer and reducing the risk of optical waveguide deformation;

[0036] 2. By installing a barrier unit at the connection between the buffer chamber and the external environment, the risk of water and particulate matter entering during pressure exchange can be reduced;

[0037] 3. By setting up a drying layer and / or a dry inert gas, the internal humidity can be further reduced, thereby improving the stability of the optical area;

[0038] 4. By setting a buffer layer between the adhesive layer and the optical waveguide, especially in the corner area of ​​the optical waveguide, the edge stress concentration can be reduced and the structural reliability can be improved. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall structure of an optical waveguide packaging structure in Embodiment 1 of this application.

[0040] Figure 2 yes Figure 1 A magnified view of a portion of point A in the middle.

[0041] Figure 3 This is a schematic diagram of an optical waveguide packaging structure in Embodiment 2 of this application.

[0042] Figure 4 This is a schematic diagram of an optical waveguide packaging structure in Embodiment 3 of this application.

[0043] Figure 5 yes Figure 4 A magnified view of a section at point B.

[0044] Figure 6 This is a flowchart of a packaging method for an optical waveguide packaging structure according to an embodiment of this application.

[0045] Explanation of reference numerals in the attached figures:

[0046] 1. Rigid frame; 11. Pressure equalization channel; 12. Buffer chamber; 13. Barrier unit; 14. Drying layer; 15. Protective components; 151. Filter sheet; 152. Adhesive-blocking protrusion; 2. Optical waveguide; 3. Gap layer; 4. Adhesive layer; 5. Buffer layer; 6. Cover plate; 7. Base plate. Detailed Implementation

[0047] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0048] This application discloses an optical waveguide packaging structure.

[0049] It should be noted that, in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this invention.

[0050] Example 1: Refer to Figure 1 An optical waveguide packaging structure includes a rigid frame 1 and at least two layers of optical waveguides 2 stacked on the rigid frame 1. A gap layer 3 is provided between adjacent optical waveguides 2, and a preset angle is provided between adjacent optical waveguides 2. The preset angle can be set according to optical design requirements to achieve coupling in, transmission, and coupling out of different optical paths.

[0051] The rigid frame 1 can be a metal frame, a ceramic frame, or a high-rigidity composite material frame. In this embodiment, the rigid frame 1 is a metal frame. A pressure equalization channel 11 and a buffer cavity 12 are respectively provided in the rigid frame 1.

[0052] One end of the equalizing channel 11 is connected to the gap layer 3, and the other end of the equalizing channel 11 is connected to the buffer cavity 12. The buffer cavity 12 is connected to the external environment, thereby forming an indirect communication path between the gap layer 3 and the external environment through the equalizing channel 11 and the buffer cavity 12.

[0053] A barrier unit 13 is provided inside the buffer chamber 12. The barrier unit 13 is located on the communication path between the buffer chamber 12 and the external environment, so that gas from the external environment must pass through the barrier unit 13 before entering the buffer chamber 12. The barrier unit 13 is used to block water and particulate matter from passing through and limits the gas exchange rate. Thus, while achieving slow gas exchange, it can reduce the risk of external liquid water, particulate matter, and larger pollutants entering the buffer chamber 12 and the gap layer 3.

[0054] In this embodiment, the barrier unit 13 includes a hydrophobic and breathable membrane, thereby achieving slow gas exchange to balance the pressure difference while effectively blocking liquid water and dust particles. The barrier unit 13 can be further selected from materials that meet the following performance indicators: air permeability in the range of 0.5-10 L / (m²·h), waterproof rating not lower than IPX4, and particle filtration efficiency not lower than 99% (for 0.3μm particles). A typical material for the barrier unit 13 is a polytetrafluoroethylene (PTFE) expanded microporous membrane, which has inherent hydrophobic and breathable properties, and its pore size can be controlled within the range of 0.1-1μm. If the pore size is greater than 1μm, when the external humidity is high or there are air pressure fluctuations, water vapor easily condenses and permeates through the micropores, causing condensation on the inner surface of the optical waveguide and producing optical speckle. If the pore size is less than 0.1μm, the gas permeability (Gurley value) will decrease exponentially. When AR glasses are worn quickly (generating instantaneous compressed air pressure), the gas cannot be expelled in time, causing the waveguide sheet to deform like a "drum," resulting in momentary visual ghosting.

[0055] In another embodiment, the barrier unit 13 may also adopt a composite structure consisting of a hydrophobic and breathable membrane and an activated carbon adsorption layer. The hydrophobic and breathable membrane is located on the outside to block water and particulate matter, and the activated carbon adsorption layer is located on the inside to adsorb volatile organic compounds, thereby further improving the gas cleanliness within the gap layer 3.

[0056] A drying layer 14 is provided inside the buffer chamber 12, and the drying layer 14 is located between the pressure equalization channel 11 and the barrier unit 13. Before entering the pressure equalization channel 11, the gas in the external environment can pass through the drying layer 14, thereby reducing the humidity of the gas entering the gap layer 3.

[0057] Preferably, the equivalent diameter of the pressure equalization channel is d=0.02mm, and the equivalent diameter of the buffer cavity is D=1.0mm, with a diameter ratio of 1:50. Fluid simulation tests show that at this ratio, when an external step pressure pulse of 100Pa is input, the airflow velocity entering the gap layer 3 is reduced by more than 85%, and the pressure fluctuation quickly stabilizes within 10ms, effectively suppressing the micro-vibrations of the optical waveguide 2.

[0058] The drying layer 14 is a granular drying material filled in the buffer cavity 12. In this embodiment, the granular drying material can be silica gel or 3A molecular sieve, which can dehumidify the gas exchanged through the buffer cavity 12. In other embodiments, the drying layer 14 can also be a sheet-like drying element fixedly disposed on the inner wall of the buffer cavity 12.

[0059] Reference Figure 1 and Figure 2The pressure equalization channel 11 is formed inside the side wall of the rigid frame 1, and the pressure equalization channel 11 is tortuous, thereby extending the gas passage path and slowing down the gas diffusion rate. Each gap layer 3 corresponds to at least two pressure equalization channels 11. In this embodiment, each gap layer 3 corresponds to two pressure equalization channels 11, so that each gap layer 3 can be connected to the buffer chamber 12 through two pressure equalization channels 11 respectively, so that even if one pressure equalization channel 11 is affected by contamination or partial blockage, the other pressure equalization channels 11 can still maintain pressure equalization capability.

[0060] In this embodiment, the minimum cross-sectional area of ​​the pressure equalization channel 11 is smaller than the average cross-sectional area of ​​the buffer cavity 12, making the pressure equalization channel 11 form a throttling structure relative to the buffer cavity 12. When gas flows from the gap layer 3 to the buffer cavity 12 or from the buffer cavity 12 to the gap layer 3, it must pass through the pressure equalization channel 11 with its smaller cross-sectional area, thus being limited by flow resistance and further reducing the gas exchange rate. Simultaneously, the buffer cavity 12 has a larger average cross-sectional area, resulting in a relatively larger internal volume, which can provide a better buffering effect when pressure changes occur, reducing the amplitude of pressure fluctuations.

[0061] A protective component 15 is provided on the side of the equalizing channel 11 near the gap layer 3. Since adhesive material is usually applied around the optical waveguide 2 when encapsulating it with the rigid frame 1, the adhesive material may diffuse from the edge region of the gap layer 3 towards the inlet of the equalizing channel 11 in a flowing state. After the protective component 15 is provided, it can block this inlet and reduce the possibility of adhesive material intruding into the equalizing channel 11.

[0062] The protective component 15 includes a filter sheet 151 and a baffle protrusion 152. The filter sheet 151 is disposed at one end of the pressure equalization channel 11 near the gap layer 3, and the filter sheet 151 has multiple micropores. The filter sheet 151 covers the inlet area of ​​the pressure equalization channel 11, and the multiple micropores are used to allow gas to pass through while restricting larger impurities or flowing adhesive materials.

[0063] In this embodiment, the filter 151 can be a sintered metal microporous sheet or a ceramic microporous sheet, with a micropore diameter ranging from 5 to 50 μm, allowing gas molecules to pass freely while effectively blocking the flow of adhesive material. The outer contour of the filter 151 is adapted to the inlet cross-section of the pressure equalization channel 11, and it can be fixed to the inlet of the pressure equalization channel 11 by pressing or welding.

[0064] An adhesive-blocking protrusion 152 is disposed on the inner wall of the rigid frame 1 and surrounds the filter 151. The height of the adhesive-blocking protrusion 152 ranges from 0.05mm to 0.3mm, and the width ranges from 0.1mm to 0.5mm, forming a continuous or discontinuous raised boundary around the filter 151. When the adhesive material flows along the gap between the optical waveguide 2 and the rigid frame 1, the adhesive-blocking protrusion 152 can significantly reduce the probability of the adhesive material crossing this area to reach the surface of the filter 151.

[0065] In this embodiment, the optical waveguide 2 is provided with three layers, which are stacked on the rigid frame 1 along the thickness direction. The three optical waveguides 2 are a single blue light waveguide, a single green light waveguide, and a single red light waveguide, respectively. Protective glass layers can also be selectively provided on the upper and lower sides of at least two optical waveguides 2.

[0066] An adhesive layer 4 is provided between the optical waveguide 2 and the rigid frame 1 to fix the optical waveguide 2 to the rigid frame 1 and to cooperate with the rigid frame 1 to form a sealed boundary around the gap layer 3. In this embodiment, the adhesive layer 4 can be a UV-curable adhesive or a visible-light curable adhesive.

[0067] A buffer layer 5 is disposed between the adhesive layer 4 and the optical waveguide 2. The elastic modulus of the buffer layer 5 is lower than that of the adhesive layer 4. When external mechanical impact, thermal expansion difference, or assembly stress is applied to the edge area, the buffer layer 5 can deform preferentially, thereby reducing the degree to which stress is directly transmitted to the optical waveguide 2.

[0068] In this embodiment, the buffer layer 5 is made of a two-component flexible epoxy resin material and is disposed in the corner region of the optical waveguide 2. The corner region is a location with a large change in edge contour, which is usually more prone to stress concentration. Therefore, placing the buffer layer 5 in this location is more beneficial to improving local reliability. In other embodiments, the buffer layer 5 may not be provided.

[0069] After encapsulation, the gap layer 3, pressure equalization channel 11, and buffer cavity 12 are replaced with inert gas to create a low-humidity environment inside. The dry inert gas filling the gap layer 3, pressure equalization channel 11, and buffer cavity 12 can further reduce the internal moisture content and reduce the adverse effects of the active environment on the structure.

[0070] It should be noted that the inert gas filling is the initial state when the encapsulation is completed. During long-term use, the inert gas concentration in the gap layer 3 will slowly decrease due to the gas exchange rate limited by the barrier unit 13, but it can still maintain a high inert gas concentration within the design service life.

[0071] An optical waveguide packaging structure further includes a cover plate 6 and a base plate 7. The cover plate 6 and the base plate 7 are located on opposite sides of the rigid frame 1 and are fixedly connected to the rigid frame 1 to enclose the optical waveguide 2, which is stacked and fixedly disposed on the rigid frame 1.

[0072] Positive pressure operation: When the ambient temperature rises, the gas inside the gap layer 3 expands, and the gas pressure inside the gap layer 3 is higher than the ambient pressure. At this time, the gas inside the gap layer 3 slowly diffuses to the buffer cavity 12 through the pressure equalization channel 11. Since the pressure equalization channel 11 is tortuous, the gas diffusion rate is further reduced, avoiding the impact of instantaneous pressure release on the surface of the optical waveguide 2. The gas in the buffer cavity 12 then passes through the drying layer 14 and is slowly discharged to the outside through the barrier unit 13 until the gas pressure inside and outside the gap layer 3 reaches equilibrium. Throughout the process, the rigid frame 1, the adhesive layer 4, and the surface of the optical waveguide 2 remain in a rigid support state without any deformation of the solid boundaries, thus not affecting the preset included angle.

[0073] Negative pressure operation: When the ambient temperature decreases, the gas inside the gap layer 3 contracts, and the gas pressure inside the gap layer 3 becomes lower than the ambient air pressure. At this time, external gas slowly enters the buffer chamber 12 through the barrier unit 13, and after moisture is removed by the drying layer 14, it is slowly replenished to the gap layer 3 through the pressure equalization channel 11 until the internal and external gas pressures are balanced. During this process, the barrier unit 13 simultaneously blocks the entry of external liquid water and particulate matter, ensuring the cleanliness of the gap layer 3.

[0074] The implementation principle of the optical waveguide packaging structure in this application embodiment is as follows: When the external air pressure or temperature changes, the gas inside the gap layer 3 can be slowly released through the pressure equalization channel 11 and the buffer cavity 12, thereby reducing or eliminating the mechanical stress or deformation caused by the pressure difference inside and outside the gap layer 3 on the optical waveguide 2. At the same time, the barrier unit 13, which is set at the connection between the buffer cavity 12 and the external environment, allows the gas to diffuse slowly while blocking liquid water, water vapor and particulate matter, thereby achieving the pressure equalization function while protecting the cleanliness and dryness of the gap layer 3. Furthermore, by setting the protective component 15 at the inlet of the pressure equalization channel 11, the adhesive material during the packaging process can be prevented from flowing in and blocking the channel, ensuring the long-term effectiveness of the pressure equalization path; by setting the low elastic modulus buffer layer 5 at the edge of the optical waveguide 2, especially in the corner area, the local stress caused by thermal expansion and contraction or mechanical impact can be effectively dispersed and absorbed, reducing the risk of damage to the edge of the optical waveguide 2, and ultimately improving the structural stability and environmental adaptability of the entire packaging structure.

[0075] Unlike existing elastic structure schemes that adjust the volume of the gap layer 3 through boundary deformation to achieve pressure equalization, this application employs an indirect gas exchange principle: gas within the gap layer 3 diffuses through the pressure equalization channel 11 to the buffer cavity 12, and the buffer cavity 12 then slowly exchanges gas with the external environment through the barrier unit 13. During this process, all solid boundaries of the gap layer 3 (rigid frame 1, adhesive layer 4, and the surface of the optical waveguide 2) remain rigid and undeformed. Pressure balance is achieved entirely through the slow diffusion of gas molecules, rather than through the elastic deformation of any solid boundary. Therefore, this scheme does not alter the boundary constraints of the optical waveguide 2 during the pressure equalization process, fundamentally avoiding interference with the stability of the preset angle.

[0076] Furthermore, the pressure equalization channel 11 extends in a tortuous shape, lengthening the gas diffusion path and making pressure changes smoother, thus avoiding the impact of instantaneous pressure fluctuations on the optical waveguide 2. Each gap layer 3 corresponds to at least two pressure equalization channels 11, so even if one channel becomes blocked, the pressure equalization function can still be maintained through the other channels. The protective component 15 is located on the side of the pressure equalization channel 11 near the gap layer 3, effectively preventing adhesive material from entering the pressure equalization channel 11 and causing blockage during the encapsulation process. The above multi-layered design works together to ensure the long-term reliability of the pressure equalization path.

[0077] Example 2: Refer to Figure 3 The difference between this embodiment and embodiment 1 is that: multiple buffer cavities 12 are provided, and the multiple buffer cavities 12 are distributed at intervals along the circumference of the rigid frame 1. Each buffer cavity 12 is connected to the gap layer 3 through its corresponding pressure equalization channel 11, and each buffer cavity 12 is provided with a barrier unit 13.

[0078] By distributing multiple buffer cavities 12 across different sidewalls of the rigid frame 1, different regions of the gap layer 3 can achieve pressure equalization connectivity nearby, improving the uniformity of pressure distribution within the gap layer 3. When a pressure change occurs in a local area of ​​the gap layer 3, the buffer cavities 12 near that area can respond preferentially, shortening the pressure transmission path and reducing the impact of local pressure differences on the optical waveguide 2. Simultaneously, the multiple buffer cavities 12 constitute a distributed pressure equalization system. Even if individual buffer cavities 12 or their corresponding pressure equalization channels 11 become blocked or fail, the other buffer cavities 12 can still maintain their pressure equalization function, improving the system's fault tolerance and long-term reliability.

[0079] In other embodiments, the volume of each buffer cavity 12 can be the same, or it can be designed differently according to the differences in length and thickness of each sidewall of the rigid frame 1. For example, the volume of the buffer cavity 12 in the longer sidewall of the rigid frame 1 can be larger than the volume of the buffer cavity 12 in the shorter sidewall, so as to match the pressure equalization requirements of different areas.

[0080] Example 3: Reference Figure 4 and Figure 5 The difference between this embodiment and Embodiment 1 is that the equalizing channel 11 includes a main channel and at least two branch channels. One end of the main channel is connected to the buffer chamber 12, and the other end of the main channel branches to form at least two branch channels, each of which is connected to the gap layer 3. In this case, the protective component 15 is disposed at each branch channel.

[0081] By employing a tree-like branching structure for the pressure equalization channel 11, a single buffer cavity 12 can simultaneously establish connections with multiple locations in the gap layer 3 through a main channel. Compared to setting an independent pressure equalization channel 11 for each connection location, the tree-like branching structure can reduce the total number of channels in the rigid frame 1, reduce processing complexity, and still ensure that multiple regions of the gap layer 3 obtain pressure equalization connectivity.

[0082] In other embodiments, the cross-sectional area of ​​each branch channel can be the same, or it can be differentiated according to the area of ​​the gap layer 3 region corresponding to each branch channel. The ends of each branch channel can be distributed at different positions on the inner wall of the rigid frame 1 to improve the uniformity of pressure distribution inside the gap layer 3.

[0083] This application also discloses a packaging method for an optical waveguide packaging structure.

[0084] Reference Figure 1 and Figure 6 A packaging method for an optical waveguide packaging structure includes the following steps:

[0085] This packaging method is used to package the optical waveguide packaging structure in any of the above embodiments, and includes the following steps:

[0086] S1, a rigid frame 1 is provided, in which a pressure equalization channel 11 and a buffer cavity 12 are formed, and the buffer cavity 12 is connected to the external environment, and a barrier unit 13 is provided in the buffer cavity 12.

[0087] Specifically, a pressure equalization channel 11 can be formed inside the sidewall of the rigid frame 1 through machining, laser processing, injection molding, or 3D printing, while a buffer cavity 12 is formed in the rigid frame 1. The buffer cavity 12 is connected to the external environment through an opening. A barrier unit 13 is set at the corresponding environmental exchange position inside the buffer cavity 12 to establish an environmental protection path during the structure formation stage.

[0088] In other embodiments, the rigid frame 1 can also be formed by splicing two or more upper and lower parts, with grooves for the channel pre-processed on the joint surfaces of the parts, so that a closed internal channel is formed after splicing.

[0089] Reference Figure 1 and Figure 2If a drying layer 14 is required, it can be installed in the buffer cavity 12 during this step, with the drying layer 14 positioned between the pressure equalization channel 11 and the barrier unit 13. If a protective component 15 is required, a filter 151 can be installed at the port of the pressure equalization channel 11 during this step, and a baffle protrusion 152 can be formed on the inner wall of the rigid frame 1 surrounding the filter 151.

[0090] S2 provides at least two layers of optical waveguide 2, and adjusts the position and angle of the multilayer optical waveguide 2. In this embodiment, the optical waveguide 2 is provided with three layers.

[0091] Specifically, the three optical waveguides 2 are placed on alignment fixtures, and a test image is projected into the coupling region of the optical waveguides 2 by an optomechanical system. In the coupling region, a camera is used to observe whether the images displayed by each optical waveguide 2 overlap. Based on the observation results, the relative positions and relative angles of each optical waveguide 2 are adjusted until the images of each optical waveguide 2 meet the registration requirements.

[0092] S3, fix the aligned and adjusted optical waveguide 2 to the rigid frame 1, so that a gap layer 3 is formed between two adjacent optical waveguides 2, and the gap layer 3 is connected to the buffer cavity 12 through the equalization channel 11.

[0093] Specifically, an adhesive material is applied between the edge of the optical waveguide 2 and the rigid frame 1 to form an adhesive layer 4, so that the adhesive layer 4 and the rigid frame 1 together enclose the sealing boundary of the gap layer 3. If a buffer layer 5 is required, the buffer layer 5 can be set on the surface of the corner area of ​​the optical waveguide 2 before applying the adhesive material, and then the adhesive material can be applied to the outside of the buffer layer 5.

[0094] After the fixation is completed, the gap layer 3 is connected to the pressure equalization channel 11, the pressure equalization channel 11 is connected to the buffer cavity 12, and the buffer cavity 12 is connected to the external environment, thereby establishing a complete indirect connection path.

[0095] When it is necessary to fill with dry inert gas, after the fixing is completed, dry inert gas can be introduced into the gap layer 3, the pressure equalization channel 11 and the buffer chamber 12 through the opening 121 of the buffer chamber 12 or the specially designed gas filling port to replace the gas, so that the gas environment along the entire gas exchange path remains in a low-humidity inert state.

[0096] The implementation principle of the packaging method for an optical waveguide packaging structure in this application is as follows: First, functional structures such as a voltage equalization channel 11, a buffer cavity 12, and a blocking unit 13 are constructed in a rigid frame 1. Then, the alignment adjustment and fixed packaging of the multilayer optical waveguide 2 are completed, so that the final gap layer 3 not only meets the optical assembly requirements but also has voltage equalization and environmental protection capabilities. This packaging method has clear steps and controllable processes, which is conducive to the mass production of multilayer optical waveguide packaging structures.

[0097] This application also discloses an augmented reality optical device.

[0098] Reference Figure 1 An augmented reality optical device includes the aforementioned optical waveguide packaging structure. The augmented reality optical device can be an optical display module in a head-mounted display device, or it can be smart glasses, a head-up display, or other display devices that require a multi-layered optical waveguide structure for image transmission and emission.

[0099] Because augmented reality optical devices employ the aforementioned waveguide packaging structure, they can better control pressure changes, humidity changes, and particulate contamination risks in the gap layer 3 during device operation, transportation, and environmental changes. This also reduces the impact of boundary stress concentration on display quality and structural reliability, thereby improving the display quality and reliability of augmented reality optical devices.

[0100] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An optical waveguide packaging structure, characterized in that, include: A rigid frame (1) and at least two layers of optical waveguides (2) stacked on the rigid frame (1), with a gap layer (3) between adjacent two layers of optical waveguides (2) and a preset angle between adjacent two layers of optical waveguides (2); The rigid frame (1) is provided with a pressure equalization channel (11) and a buffer cavity (12). One end of the pressure equalization channel (11) is connected to the gap layer (3), and the other end of the pressure equalization channel (11) is connected to the buffer cavity (12). The buffer cavity (12) is connected to the external environment. A barrier unit (13) is provided in the buffer cavity (12). The barrier unit (13) is located on the communication path between the buffer cavity (12) and the external environment. The barrier unit (13) is used to block water and particulate matter from passing through and limits the gas exchange rate.

2. The optical waveguide packaging structure according to claim 1, characterized in that: A drying layer (14) is provided inside the buffer cavity (12), and the drying layer (14) is located between the pressure equalization channel (11) and the barrier unit (13).

3. The optical waveguide packaging structure according to claim 1, characterized in that: The equalizing channel (11) extends along the sidewall of the rigid frame (1) and is tortuous, and each gap layer (3) corresponds to at least two equalizing channels (11).

4. The optical waveguide packaging structure according to claim 1, characterized in that: A protective component (15) is provided on the side of the pressure equalization channel (11) near the gap layer (3). The protective component (15) is used to prevent adhesive material from entering the pressure equalization channel (11).

5. The optical waveguide packaging structure according to claim 4, characterized in that: The protective component (15) includes a filter sheet (151) and a baffle protrusion (152). The filter sheet (151) is disposed at one end of the pressure equalization channel (11) near the gap layer (3). The filter sheet (151) has multiple micropores. The baffle protrusion (152) is disposed on the inner wall of the rigid frame (1) and surrounds the filter sheet (151). The height of the baffle protrusion (152) is in the range of 0.05mm-0.3mm. The baffle protrusion (152) forms a closed or semi-closed baffle boundary on the inner wall of the rigid frame (1).

6. The optical waveguide packaging structure according to claim 1, characterized in that: An adhesive layer (4) is provided between the optical waveguide (2) and the rigid frame (1). The adhesive layer (4) and the rigid frame (1) together form the sealing boundary of the gap layer (3). A buffer layer (5) is provided between the adhesive layer (4) and the optical waveguide (2). The elastic modulus of the buffer layer (5) is lower than that of the adhesive layer (4).

7. The optical waveguide packaging structure according to claim 1, characterized in that: The barrier unit (13) includes a hydrophobic and breathable membrane with an average pore size of 0.1 μm-1 μm; the minimum cross-sectional area of ​​the pressure equalization channel (11) is smaller than the average cross-sectional area of ​​the buffer cavity (12).

8. The optical waveguide packaging structure according to claim 1, characterized in that: The gap layer (3), the pressure equalization channel (11), and the buffer cavity (12) are all filled with dry inert gas.

9. A packaging method for an optical waveguide packaging structure, used to package the optical waveguide packaging structure as described in any one of claims 1-8, characterized in that, Includes the following steps: A rigid frame (1) is provided, in which the pressure equalization channel (11) and the buffer cavity (12) are formed, and the buffer cavity (12) is connected to the external environment. A barrier unit (13) is provided in the buffer cavity (12). Provide at least two layers of optical waveguides (2) and adjust the position and angle of the multilayer optical waveguides (2); The optical waveguide (2) after alignment adjustment is fixed to the rigid frame (1) so that a gap layer (3) is formed between two adjacent optical waveguides (2), and the gap layer (3) is connected to the buffer cavity (12) through the equalization channel (11).

10. An augmented reality optical device, characterized in that: Includes the optical waveguide packaging structure as described in any one of claims 1-8.

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