Coating method for diffractive optical waveguide

Abstract

The application discloses a coating method of a diffraction optical waveguide, and relates to the technical field of diffraction optical waveguides. The coating method comprises the following steps: placing a waveguide to be coated on a waveguide bearing surface of a clamping tool, and arranging a first magnetic part on the side of the clamping tool away from the waveguide bearing surface; covering a second magnetic part with a magnetic polarity opposite to that of the first magnetic part on a grating structure area of the waveguide to be coated, so as to adsorb and fix the grating structure area and the waveguide to be coated based on the magnetic force between the first magnetic part and the second magnetic part; and coating the surface to be coated of the waveguide to be coated, so as to form an anti-reflection film on the non-grating area of the waveguide to be coated. The application can improve the optical performance of the diffraction optical waveguide without affecting the coating effect of the diffraction optical waveguide.

Description

Technical Field

[0001] This application relates to the field of diffractive waveguide technology, and in particular to a coating method for diffractive waveguides. Background Technology

[0002] In the manufacturing process of diffractive waveguides, nanoimprint technology is widely used due to its high precision and efficiency. During nanoimprinting, to enhance the diffraction effect of the grating and improve the overall efficiency of the waveguide, an imprinting adhesive with a refractive index higher than the substrate material is typically chosen as the material constituting the grating. This leads to a significant increase in the surface reflectivity of non-grating areas. However, in the use of head-mounted displays such as AR (Augmented Reality) devices and VR (Virtual Reality) devices, strong reflections occur when external light shines on non-grating areas, creating glare and causing visual interference, thus affecting the wearing experience.

[0003] To mitigate this issue, an antireflective coating with a lower refractive index than the imprinted adhesive in the non-grating areas can be deposited to reduce reflectivity and thus minimize glare. However, since the grating structure region in the waveguide is an isolated area, and the waveguide needs to be inverted during deposition, traditional deposition fixtures and methods inevitably result in some areas that do not require deposition being coated with an antireflective coating. This affects the precision of the coating area and the uniformity of the film, causing discoloration on the waveguide surface and impacting its appearance. Consequently, the waveguide's performance suffers, resulting in poor coating quality and affecting the optical performance of the diffractive waveguide. Summary of the Invention

[0004] The main objective of this application is to provide a coating method for diffractive optical waveguides, which aims to improve the optical performance of diffractive optical waveguides without affecting the coating effect.

[0005] This application provides a coating method for a diffractive optical waveguide, the method comprising: The waveguide to be coated is placed on the waveguide bearing surface of the positioning fixture, and a first magnetic element is provided on the side of the positioning fixture away from the waveguide bearing surface. A second magnetic element with the opposite magnetic polarity to the first magnetic element is placed on the grating structure region of the waveguide to be coated, so that the grating structure region and the waveguide to be coated are adsorbed and fixed based on the magnetic force between the first magnetic element and the second magnetic element. A coating is applied to the surface of the waveguide to be coated to form an antireflection coating in the non-grating region of the waveguide.

[0006] In one embodiment, prior to the step of covering the grating structure region of the waveguide to be coated with a second magnetic element having a magnetic polarity opposite to that of the first magnetic element, the method further includes: The grating structure region positioning fixture is placed on the coating surface of the waveguide to be coated, so that the grating structure region is exposed relative to the surrounding non-grating region; After exposing the grating structure region, the step of covering the grating structure region of the waveguide to be coated with a second magnetic element with a magnetic polarity opposite to that of the first magnetic element is performed. After the step of covering the grating structure region of the waveguide to be coated with a second magnetic element having a magnetic polarity opposite to that of the first magnetic element, the method further includes: Remove the grating structure area positioning fixture placed on the surface to be coated, and perform the step of coating the surface of the waveguide to be coated.

[0007] In one embodiment, the waveguide to be coated is provided with a first positioning part, and the step of placing the grating structure region positioning fixture on the coating surface of the waveguide to be coated includes: A second positioning part matching the first positioning part is provided on the positioning fixture of the grating structure area; The first positioning part and the second positioning part are aligned and matched to place the grating structure area positioning fixture on the coating surface of the waveguide to be coated.

[0008] In one embodiment, after the step of placing the grating structure region positioning fixture on the coating surface of the waveguide to be coated, the method further includes: The positioning fixture for the grating structure area is fixedly connected to the locking fixture by a fastener; Before the step of removing the positioning fixture for the grating structure area placed on the surface to be coated, the method further includes: Remove the fixing piece from the positioning fixture of the grating structure area.

[0009] In one embodiment, prior to the step of covering the grating structure region of the waveguide to be coated with a second magnetic element having a magnetic polarity opposite to that of the first magnetic element, the method further includes: A protective element is provided on the magnetic element covering surface of the grating structure region, and after the protective element is provided, the step of covering the grating structure region of the waveguide to be coated with a second magnetic element with a magnetic polarity opposite to that of the first magnetic element is performed.

[0010] In one embodiment, before the step of placing the waveguide to be coated onto the waveguide bearing surface of the positioning fixture, the method further includes: Obtain waveguide bearing dimensions that match the external dimensions of the waveguide to be coated; The size of the waveguide bearing area on the waveguide bearing surface of the positioning fixture is adjusted to the waveguide bearing size, and after adjustment, the step of placing the waveguide to be coated on the waveguide bearing surface of the positioning fixture is performed.

[0011] In one embodiment, the method further includes: In the case of multiple waveguides to be coated, the first target size of the positioning fixture and the second target size of each waveguide bearing area on the waveguide bearing surface of the positioning fixture are determined according to the external dimensions of each waveguide to be coated. The dimensions of the positioning fixture are adjusted to the first target dimensions, and the dimensions of each waveguide bearing area in the positioning fixture are adjusted to their respective second target dimensions.

[0012] In one embodiment, the step of determining the first target size of the positioning fixture and the second target size of each waveguide bearing area on the waveguide bearing surface of the positioning fixture based on the external dimensions of each of the waveguides to be coated includes: Obtain waveguide bearing dimensions that match the external dimensions of each of the waveguides to be coated, and use them as the second target dimensions of the bearing regions of each of the waveguides; The first target size of the positioning fixture is determined based on the second target size of each waveguide bearing region and the layout position of each waveguide bearing region on the positioning fixture.

[0013] In one embodiment, before the step of coating the surface of the waveguide to be coated, the method further includes: The positioning fixture and the waveguide to be coated are flipped so that the coating surface is facing down. An image of the second magnetic component covering the grating structure area is acquired using an image acquisition device; Based on the image, determine whether the second magnetic component completely covers the grating structure area; If so, then perform the step of coating the surface of the waveguide to be coated; If not, adjust the coverage position of the second magnetic element in the grating structure area, and return to the step of acquiring the image of the second magnetic element from bottom to top using the image acquisition device.

[0014] In one embodiment, before the step of coating the surface of the waveguide to be coated, the method further includes: The magnetic force between the first magnetic component and the second magnetic component is collected by a pressure sensor; Determine whether the magnetic force is greater than or equal to a preset magnetic force threshold; If so, then perform the step of coating the surface of the waveguide to be coated; If not, replace the first magnetic component and / or the second magnetic component, and return to the step of determining whether the magnetic force is greater than the preset magnetic force threshold.

[0015] This application provides a coating method for a diffractive waveguide, comprising: placing the waveguide to be coated on the waveguide bearing surface of a positioning fixture, and setting a first magnetic element on the side of the positioning fixture away from the waveguide bearing surface; covering the grating structure region of the waveguide to be coated with a second magnetic element having a magnetic polarity opposite to that of the first magnetic element, so as to adsorb and fix the grating structure region and the waveguide to be coated based on the magnetic force between the first magnetic element and the second magnetic element; and coating the surface of the waveguide to be coated to form an antireflection film in the non-grating region of the waveguide to be coated.

[0016] Therefore, the technical solution provided in this application, before coating the waveguide to be coated, places the waveguide to be coated on the waveguide bearing surface of a clamping fixture equipped with a first magnetic element, and covers the grating structure area of ​​the waveguide to be coated with a second magnetic element with the opposite magnetic polarity to the first magnetic element. Thus, under the magnetic force between the first and second magnetic elements, the grating structure area and the waveguide to be coated can be adsorbed and fixed between the first and second magnetic elements. Consequently, when coating the surface of the waveguide to be coated, the grating structure area and the waveguide to be coated will not fall off due to the inversion of the waveguide, and since the grating structure area is covered by the second magnetic element, it can be ensured that an antireflection coating will not be deposited on the grating structure area during coating.

[0017] In summary, the technical solution provided in this application can improve the optical performance of the diffractive waveguide without affecting the coating effect. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic flowchart of the coating method for the diffractive waveguide provided in the first embodiment of this application; Figure 2A schematic diagram illustrating the implementation principle of the coating method for the diffractive waveguide provided in the first embodiment of this application; Figure 3 A schematic diagram illustrating the implementation principle of the coating method for the diffractive waveguide provided in the second embodiment of this application; Figure 4 Another implementation principle diagram of the coating method for the diffractive waveguide provided in the second embodiment of this application; Figure 5 A schematic diagram illustrating the implementation principle of the coating method for the diffractive waveguide provided in the third embodiment of this application; Figure 6 This is an example diagram showing a positioning fixture provided in the fifth embodiment of this application, which simultaneously holds multiple waveguides to be coated.

[0021] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0022] Explanation of icon numbers: 1. Waveguide to be coated; 2. Positioning fixture; 3. First magnetic component; 4. Second magnetic component; 5. Positioning fixture for grating structure area; 6. First positioning part; 7. Second positioning part; 8. Fixing component; 9. Protective component. Detailed Implementation

[0023] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0024] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0025] Nanoimprint lithography is widely used in the manufacturing of diffractive waveguides due to its high precision and efficiency. During nanoimprint lithography, to enhance the diffraction effect of the grating and improve the overall efficiency of the waveguide, an imprinting adhesive with a refractive index higher than the substrate material is typically chosen as the material constituting the grating. This leads to a significant increase in the surface reflectivity of the non-grating areas. However, in head-mounted display devices such as AR (Augmented Reality) and VR (Virtual Reality) devices, external light shining on the non-grating areas can negatively impact the wearing experience.

[0026] To mitigate this issue, an antireflective coating with a lower refractive index than the imprinted adhesive in the non-grating areas can be deposited to reduce reflectivity and thus minimize glare. However, since the grating structure region in the waveguide is an isolated area, and the waveguide needs to be inverted during deposition, traditional deposition fixtures and methods inevitably result in some areas that do not require deposition being coated with an antireflective coating. This affects the precision of the coating area and the uniformity of the film, causing discoloration on the waveguide surface and impacting its appearance. Consequently, the waveguide's performance suffers, resulting in poor coating quality and affecting the optical performance of the diffractive waveguide.

[0027] Based on this, this application provides a coating method for a diffractive waveguide, comprising: placing the waveguide to be coated on the waveguide bearing surface of a positioning fixture, and setting a first magnetic element on the side of the positioning fixture away from the waveguide bearing surface; covering the grating structure region of the waveguide to be coated with a second magnetic element having a magnetic polarity opposite to that of the first magnetic element, so as to adsorb and fix the grating structure region and the waveguide to be coated based on the magnetic force between the first magnetic element and the second magnetic element; and coating the surface of the waveguide to be coated to form an antireflection film in the non-grating region of the waveguide to be coated.

[0028] Therefore, the technical solution provided in this application, before coating the waveguide to be coated, places the waveguide to be coated on the waveguide bearing surface of a clamping fixture equipped with a first magnetic element, and covers the grating structure area of ​​the waveguide to be coated with a second magnetic element with the opposite magnetic polarity to the first magnetic element. Thus, under the magnetic force between the first and second magnetic elements, the grating structure area and the waveguide to be coated can be adsorbed and fixed between the first and second magnetic elements. Consequently, when coating the surface of the waveguide to be coated, the grating structure area and the waveguide to be coated will not fall off due to the inversion of the waveguide, and since the grating structure area is covered by the second magnetic element, it can be ensured that an antireflection coating will not be deposited on the grating structure area during coating.

[0029] In summary, the technical solution provided in this application can improve the optical performance of the diffractive waveguide without affecting the coating effect.

[0030] This application presents a coating method for a diffractive waveguide according to a first embodiment. Please refer to [link / reference]. Figure 1 and Figure 2 The coating method for diffractive waveguides may include steps S10 to S30: Step S10: Place the waveguide 1 to be coated on the waveguide bearing surface of the positioning fixture 2, and set the first magnetic component 3 on the side of the positioning fixture 2 away from the waveguide bearing surface; It should be noted that the waveguide 1 to be coated, i.e., the non-grating area, is the diffractive waveguide that needs to be coated with an antireflection film. The side of the positioning fixture 2 used to support (i.e., place) the waveguide 1 to be coated is called the waveguide bearing surface. The waveguide bearing surface may have waveguide bearing areas (such as positioning grooves) for supporting the waveguide 1 to be coated. The number of waveguide bearing areas on the waveguide bearing surface can be one or more, which is not specifically limited in this embodiment. The size of each waveguide bearing area can be the same or different, which is also not specifically limited in this embodiment. The magnetic component that needs to be set on the side of the positioning fixture 2 away from the waveguide bearing surface is called the first magnetic component 3. The magnetic component can be an electromagnet, a permanent magnet, or other magnetic devices, which is not specifically limited in this embodiment.

[0031] When the first magnetic component 3 is disposed on the side of the positioning fixture 2 away from the waveguide bearing surface, a groove matching the size of the first magnetic component 3 can be machined on the side of the positioning fixture 2 away from the waveguide bearing surface, thereby allowing the first magnetic component 3 to be installed in the groove. If the positioning fixture 2 itself is made of magnetically conductive material, or if a set of auxiliary magnets is pre-embedded on the side of the positioning fixture 2 away from the waveguide bearing surface, the first magnetic component 3 can be directly adsorbed onto the side of the positioning fixture 2 away from the waveguide bearing surface. This embodiment does not specifically limit the specific implementation method of disposing of the first magnetic component 3 on the side of the positioning fixture 2 away from the waveguide bearing surface.

[0032] Step S20: Cover the grating structure area of ​​the waveguide 1 to be coated with a second magnetic element 4, which has the opposite magnetic polarity to the first magnetic element 3, so as to adsorb and fix the grating structure area and the waveguide 1 to be coated based on the magnetic force between the first magnetic element 3 and the second magnetic element 4. It should be noted that the magnetic component that needs to cover the grating structure area is referred to as the second magnetic component 4. To ensure that the second magnetic component 4 can completely cover the grating structure area, the size of the second magnetic component 4 can be set to match the size of the grating structure area (for example, the size of the second magnetic component 4 is equal to or slightly larger than the size of the grating structure area).

[0033] Step S30: Deposit a coating on the surface of the waveguide 1 to be coated to form an anti-reflection coating in the non-grating region of the waveguide 1.

[0034] It should be noted that the surface to be coated, i.e., the surface of waveguide 1 to be coated, typically includes both the grating structure region that needs to be protected (i.e., does not require antireflection coating) and the non-grating region that needs to be coated. The grating structure region refers to the micro-nano optical structure formed by techniques such as nanoimprinting, which is the core area for realizing light diffraction and transmission functions. This area needs to be protected and cannot be coated. The non-grating region refers to a flat area without optical structure. Ambient light reflection in this area will produce glare, so an antireflection coating needs to be applied to reduce reflection.

[0035] Based on the above, this embodiment provides a coating method for a diffractive waveguide, comprising: placing the waveguide 1 to be coated on the waveguide bearing surface of the positioning fixture 2, and setting a first magnetic element 3 on the side of the positioning fixture 2 away from the waveguide bearing surface; covering the grating structure area of ​​the waveguide 1 to be coated with a second magnetic element 4 having a magnetic polarity opposite to that of the first magnetic element 3, so as to adsorb and fix the grating structure area and the waveguide 1 to be coated based on the magnetic force between the first magnetic element 3 and the second magnetic element 4; and coating the surface of the waveguide 1 to be coated to form an antireflection film in the non-grating area of ​​the waveguide 1 to be coated.

[0036] Therefore, the technical solution provided in this embodiment, before coating the waveguide 1 to be coated, involves placing the waveguide 1 to be coated on the waveguide bearing surface of the positioning fixture 2 equipped with the first magnetic element 3, and covering the grating structure area of ​​the waveguide 1 to be coated with a second magnetic element 4 having the opposite magnetic polarity to the first magnetic element 3. Thus, under the magnetic force between the first magnetic element 3 and the second magnetic element 4, the grating structure area and the waveguide 1 to be coated can be adsorbed and fixed between the first magnetic element 3 and the second magnetic element 4. Consequently, when coating the surface of the waveguide 1 to be coated, the grating structure area and the waveguide 1 to be coated will not fall off due to the inversion of the waveguide under the action of the first magnetic element 3 and the second magnetic element 4. Furthermore, since the grating structure area is covered by the second magnetic element 4, it can be ensured that the grating structure area will not be coated with an antireflection film during coating.

[0037] In summary, the technical solution provided in this embodiment can improve the optical performance of the diffractive waveguide without affecting the coating effect.

[0038] Based on the first embodiment described above, a second embodiment of the coating method for the diffractive optical waveguide of this application is proposed. For the second embodiment, please refer to... Figure 3 Before step S20, the coating method for the diffractive waveguide may further include steps S21 to S24: Step S21: Place the grating structure region positioning fixture 5 on the coating surface of the waveguide 1 to be coated, so that the grating structure region is exposed relative to the surrounding non-grating region. It should be noted that the grating structure area positioning fixture 5 is used to accurately position the grating structure area of ​​the waveguide 1 to be coated, so as to precisely guide the second magnetic component 4 to be placed in the correct position. The grating structure area positioning fixture 5 can be a structure with at least one cutout window, wherein the cutout window conforms to the grating structure. Thus, after the grating structure area positioning fixture 5 is placed on the surface of the waveguide 1 to be coated, its frame will press on the non-grating area, while the cutout window can just expose the grating structure area that needs to be protected.

[0039] In one feasible implementation, to ensure that the grating structure region positioning fixture 5 can accurately position the grating structure region of the waveguide 1 to be coated, the waveguide 1 to be coated may be provided with a first positioning part 6. Therefore, step S21 may include steps S211~S212: Step S211: A second positioning part 7 matching the first positioning part 6 is provided on the positioning fixture 5 in the grating structure area; Step S212: Align and match the first positioning part 6 and the second positioning part 7 to place the grating structure area positioning fixture 5 on the coating surface of the waveguide 1 to be coated.

[0040] It should be noted that the first positioning part 6 can be a reference pattern, mark, or structure disposed on the waveguide 1 to be coated, and this embodiment does not specifically limit this. The second positioning part 7 can be a matching pattern, mark, or structure disposed on the positioning fixture 5 in the grating structure area and used in conjunction with the first positioning part 6, and this embodiment does not specifically limit this.

[0041] For example, when both the first positioning part 6 and the second positioning part 7 are graphics, after they are aligned and matched, a complete graphic (such as a solid circle or a square) can be formed.

[0042] For example, if the first positioning part 6 is a specific notch on the waveguide 1 to be coated, the second positioning part 7 can be a protrusion that matches the notch. After the two are aligned, the protrusion will fit into the notch.

[0043] Additionally, it should be noted that a first positioning part 6 can be provided on the waveguide 1 to be coated according to the position of the grating structure region of the waveguide 1 to be coated; furthermore, a second positioning part 7 can be provided on the grating structure region positioning fixture 5 according to the position of the first positioning part 6 on the waveguide 1 to be coated.

[0044] In one feasible implementation, to ensure that the position of the grating structure region positioning fixture 5 does not shift after being placed on the coating surface of the waveguide 1 to be coated, after step S21, please refer to... Figure 4 The coating method for diffractive waveguides may also include: fixing the grating structure region positioning fixture 5 to the positioning fixture 2 by means of the fixing member 8.

[0045] It should be noted that the fastener 8 can be a magnetic snap fastener, a screw snap fastener, or other devices with a fastening function, and this embodiment does not specifically limit it.

[0046] Step S22: After exposing the grating structure region, the step of covering the grating structure region of the waveguide 1 to be coated with a second magnetic element 4 with a magnetic polarity opposite to that of the first magnetic element 3 is performed.

[0047] Furthermore, after step S20, the coating method for the diffracting waveguide may further include: Step S24: Remove the grating structure area positioning fixture 5 placed on the surface to be coated, and perform the coating process on the surface to be coated of the waveguide 1.

[0048] In the case where the grating structure area positioning fixture 5 is also fixedly connected to the positioning fixture 2 by the fixing part 8, before removing the grating structure area positioning fixture 5 placed on the surface to be coated, in order to ensure that the grating structure area positioning fixture 5 can be removed smoothly, the fixing part 8 on the grating structure area positioning fixture 5 needs to be removed first, and then the grating structure area positioning fixture 5 needs to be removed.

[0049] As can be seen from the above, in this embodiment, before covering the grating structure area of ​​the waveguide 1 to be coated with the second magnetic element 4, which has the opposite magnetic polarity to the first magnetic element 3, the grating structure area positioning fixture 5 is first placed on the surface of the waveguide 1 to be coated, so that the grating structure area is exposed relative to the surrounding non-grating areas, thereby accurately positioning the position of the grating structure area. This allows for precise guidance of the second magnetic element 4 to be placed on the grating structure area, further ensuring that the grating structure area is not coated with an anti-reflection film during subsequent coating, and also ensuring that the non-grating areas are not uncoated due to mis-covering by the second magnetic element 4, thereby further improving the coating effect of the diffraction waveguide.

[0050] Based on the first and / or second embodiments described above, a third embodiment of the coating method for the diffractive optical waveguide of this application is proposed. In the third embodiment, please refer to... Figure 5 Before step S20, the coating method for the diffractive waveguide may also include step S24; Step S24: A protective element 9 is provided on the magnetic component covering surface of the grating structure area, and after the provision, a second magnetic element 4 with the opposite magnetic polarity to the first magnetic element 3 is applied to cover the grating structure area of ​​the waveguide 1 to be coated.

[0051] It should be noted that the protective component 9 can be a thin rubber pad or other device made of soft materials (such as rubber or plastic), and this embodiment does not specifically limit it.

[0052] In this embodiment, before covering the grating structure area of ​​the waveguide 1 to be coated with the second magnetic element 4, which has the opposite magnetic polarity to the first magnetic element 3, a protective element 9 is first set on the magnetic element covering surface of the grating structure area. This ensures that when the second magnetic element 4 is subsequently covered on the grating structure area of ​​the waveguide 1 to be coated, the grating structure area will not be scratched or soiled by the second magnetic element 4, thereby ensuring that the performance of the diffractive waveguide will not be affected after the coating is completed.

[0053] Based on the first, second, and / or third embodiments described above, a fourth embodiment of the coating method for the diffractive optical waveguide of this application is proposed. In the fourth embodiment, before step S10, the coating method for the diffractive optical waveguide may further include steps S01 to S02: Step S01: Obtain the waveguide bearing dimensions that match the external dimensions of the waveguide 1 to be coated; Step S02: Adjust the size of the waveguide bearing area on the waveguide bearing surface of the positioning fixture 2 to the waveguide bearing size, and after adjustment, perform the step of placing the waveguide 1 to be coated on the waveguide bearing surface of the positioning fixture 2.

[0054] It should be noted that when obtaining the waveguide bearing size that matches the external dimensions of the waveguide 1 to be coated, the sum of the external dimensions of the waveguide 1 to be coated and the preset tooling gap can be calculated as the waveguide bearing size that matches the external dimensions of the waveguide 1 to be coated; alternatively, a relational table can be used to record the waveguide bearing size corresponding to different external dimensions in advance, so that the waveguide bearing size that matches the external dimensions of the waveguide 1 to be coated can be quickly obtained by looking up the table. This embodiment does not specifically limit the specific implementation of step S01.

[0055] The preset tooling gap is used to prevent the waveguide 1 to be coated from being difficult to place, stuck or loose during the placement process in the waveguide bearing area. It can be a default value or can be flexibly set by the user according to the actual situation. This embodiment does not make specific limitations on this.

[0056] In this embodiment, before placing the waveguide 1 to be coated onto the waveguide bearing surface of the positioning fixture 2, the size of the waveguide bearing area on the waveguide bearing surface of the positioning fixture 2 is adjusted to match the outer dimensions of the waveguide 1 to be coated. This effectively avoids placement difficulties, jamming, or loosening caused by size mismatch. Therefore, it ensures that the waveguide 1 to be coated can be smoothly placed onto the waveguide bearing area on the waveguide bearing surface of the positioning fixture 2.

[0057] Based on the first, second, third, and / or fourth embodiments described above, a fifth embodiment of the coating method for the diffractive optical waveguide of this application is proposed. In the fifth embodiment, the coating method for the diffractive optical waveguide may further include steps S03 to S04: Step S03: In the case of multiple waveguides 1 to be coated, determine the first target size of the positioning fixture 2 and the second target size of each waveguide bearing area on the waveguide bearing surface of the positioning fixture 2 according to the external dimensions of each waveguide 1 to be coated. It should be noted that the first target size is the size that the entire positioning fixture 2 needs to be adjusted to, and the second target size is the size that a single waveguide bearing area needs to be adjusted to.

[0058] In one feasible implementation, step S03 may include steps S031 to S032: Step S031: Obtain the waveguide bearing dimensions that match the external dimensions of each waveguide 1 to be coated, and use them as the second target dimensions of each waveguide bearing area; It should be noted that when obtaining the waveguide bearing size that matches the external dimensions of each waveguide 1 to be coated, the sum of the external dimensions of each waveguide 1 to be coated and the preset tooling gap can be calculated as the waveguide bearing size that matches the external dimensions of each waveguide 1 to be coated; alternatively, a relational table can be used to record the waveguide bearing size corresponding to different external dimensions in advance, so that the waveguide bearing size that matches the external dimensions of each waveguide 1 to be coated can be quickly obtained by looking up the table. This embodiment does not specifically limit the specific implementation of step S031.

[0059] Step S032: Determine the first target size of the positioning fixture 2 based on the second target size of each waveguide bearing area and the layout position of each waveguide bearing area on the positioning fixture 2.

[0060] It should be noted that when determining the first target size of the positioning fixture 2 based on the second target size of each waveguide carrying area and the layout position of each waveguide carrying area on the positioning fixture 2, the area spacing between each waveguide carrying area and the edge allowance of the fixture can be determined first based on the layout position of each waveguide carrying area on the positioning fixture 2; then, the first target size of the positioning fixture 2 can be calculated using the second target size of each waveguide carrying area, the area spacing between each waveguide carrying area, and the edge allowance of the fixture.

[0061] For example, suppose there are two waveguide bearing regions, both with a second target size of 31mm × 21mm. They are arranged horizontally with a region spacing of 5mm and a tooling edge allowance of 10mm. Then: The first target dimension in the X direction = 10mm (left edge allowance) + 31mm (region 1) + 5mm (region spacing) + 31mm (region 2) + 10mm (right edge allowance) = 87mm; The first target dimension in the Y direction = 10mm (top edge allowance) + 21mm (area height) + 10mm (bottom edge allowance) = 41mm Therefore, the first target size can be determined as 87mm × 41mm.

[0062] Step S04: Adjust the size of the positioning fixture 2 to the first target size, and adjust the size of each waveguide bearing area in the positioning fixture 2 to its respective second target size.

[0063] In this embodiment, when there are multiple waveguides 1 to be coated, the overall size of the positioning fixture 2 and the size of each waveguide bearing area can be flexibly adjusted according to the external dimensions of each waveguide 1, so that multiple waveguides 1 to be coated can be placed on one positioning fixture 2 simultaneously for coating, thereby improving coating efficiency. For example, please refer to... Figure 6 Four waveguides 1 to be coated can be placed on a single fixture 2 for simultaneous coating.

[0064] Based on the first, second, third, fourth, and / or fifth embodiments described above, a sixth embodiment of the coating method for the diffractive optical waveguide of this application is proposed. In the sixth embodiment, before step S30, the coating method for the diffractive optical waveguide may further include steps S31 to S35: Step S31: Flip the positioning fixture 2 together with the waveguide 1 to be coated so that the coating surface is facing down. Step S32: Acquire an image of the second magnetic component 4 covering the grating structure area using an image acquisition device; It should be noted that the image acquisition device can be a camera, an image sensor, or other device with image acquisition capabilities, and this embodiment does not specifically limit it. Since the surface to be coated is facing down, the image acquisition device can acquire images from bottom to top when the second magnetic element 4 covers the grating structure area.

[0065] Step S33: Based on the image, determine whether the second magnetic element 4 completely covers the grating structure area; It should be noted that, when determining whether the second magnetic element 4 completely covers the grating structure area based on the image, it is possible to analyze whether all pixel features within the pixel position range corresponding to the grating structure area in the image match the features of the second magnetic element 4. If so, it can be determined that the second magnetic element 4 completely covers the grating structure area. Alternatively, the image can be segmented to identify the actual contour of the second magnetic element 4, and then the actual contour of the second magnetic element 4 can be superimposed and compared with the standard contour template of the grating structure area to determine whether the second magnetic element 4 completely covers the grating structure area. This embodiment does not specifically limit the specific implementation of step S33.

[0066] Step S34: If yes, then perform the step of coating the surface of the waveguide 1 to be coated. Step S35: If not, adjust the coverage position of the second magnetic element 4 in the grating structure area and return to the step of acquiring an image of the second magnetic element 4 from bottom to top through the image acquisition device.

[0067] It is understandable that, considering that the second magnetic component 4 may shift after the positioning fixture 2, along with the waveguide 1 to be coated, is flipped, it may fail to completely cover the grating structure area. Therefore, in this embodiment, after flipping the positioning fixture 2 along with the waveguide 1 to be coated so that the coating surface faces down, an image acquisition device is used to capture an image of the second magnetic component 4 covering the grating structure area. The captured image is used to determine whether the second magnetic component 4 completely covers the grating structure area. If it completely covers it, the coating process on the surface of the waveguide 1 to be coated can proceed normally. If it does not completely cover it, the position of the second magnetic component 4 in the grating structure area needs to be adjusted until it completely covers the grating structure area before proceeding with the coating process on the surface of the waveguide 1 to be coated. This ensures that the grating structure area will not be coated with an anti-reflection film during the coating process, and also ensures that the non-grating area will not be uncoated due to the mis-covering of the second magnetic component 4, thereby further improving the coating effect of the diffraction waveguide.

[0068] Based on the first, second, third, fourth, fifth, and / or sixth embodiments described above, a seventh embodiment of the coating method for the diffractive optical waveguide of this application is proposed. In the seventh embodiment, before step S30, the coating method for the diffractive optical waveguide may further include steps S36 to S39: Step S36: The magnetic force between the first magnetic component 3 and the second magnetic component 4 is collected by the pressure sensor; Step S37: Determine whether the magnetic force is greater than or equal to a preset magnetic force threshold. It should be noted that the preset magnetic force threshold is used as the basis for determining whether the magnetic force between the first magnetic component 3 and the second magnetic component 4 is sufficient. It can be a default value or it can be flexibly set by the user according to the actual situation. This embodiment does not make specific limitations on this.

[0069] Step S38: If yes, then perform the step of coating the surface of the waveguide 1 to be coated. Step S39: If not, replace the first magnetic component 3 and / or the second magnetic component 4 with a new one, and return to the step of determining whether the magnetic force is greater than the preset magnetic force threshold.

[0070] Before coating the surface of the waveguide 1 to be coated, this embodiment first collects the magnetic force between the first magnetic component 3 and the second magnetic component 4 through a pressure sensor. By comparing the magnetic force with a preset magnetic force threshold, it is determined whether the magnetic force between the first magnetic component 3 and the second magnetic component 4 is sufficient. If the magnetic force is greater than or equal to the preset magnetic force threshold, it means that the magnetic force between the first magnetic component 3 and the second magnetic component 4 is sufficient. At this time, when the waveguide 1 to be coated is inverted for coating, the magnetic force between the first magnetic component 3 and the second magnetic component 4 can overcome gravity and possible equipment vibration, so as to prevent the waveguide 1 to be coated and the grating structure area from falling off. If the magnetic force is less than a preset magnetic force threshold, it indicates that the magnetic force between the first magnetic component 3 and the second magnetic component 4 is insufficient. In this case, if the waveguide 1 to be coated is inverted for coating, there is a risk that the waveguide 1 to be coated and the grating structure area may fall off due to insufficient magnetic force. In this case, a new first magnetic component 3 and / or a new second magnetic component 4 can be replaced, and the process returns to the step of determining whether the magnetic force is greater than the preset magnetic force threshold until the magnetic force is sufficient. Then, the step of coating the surface of the waveguide 1 to be coated is performed. Therefore, this embodiment can further ensure that the optical performance of the diffractive waveguide is improved without affecting the coating effect of the diffractive waveguide.

[0071] In addition to determining whether the magnetic force is sufficient by directly collecting the magnetic force between the first magnetic element 3 and the second magnetic element 4, in other embodiments, the magnetic flux can be detected when selecting the first magnetic element 3 and the second magnetic element 4 to ensure that the first magnetic element 3 set on the carding fixture 2 can generate sufficient magnetic force with the second magnetic element 4 covering the grating structure area. Specifically, the magnetic flux of the first magnetic component 3 and the magnetic flux of the second magnetic component 4 can be detected by a magnetic flux sensor. Then, it can be determined whether the magnetic flux of the first magnetic component 3 is greater than or equal to a first preset magnetic flux threshold, and whether the magnetic flux of the second magnetic component 4 is greater than or equal to a second preset magnetic flux threshold. If the magnetic flux of the first magnetic component 3 is less than the first preset magnetic flux threshold, a new first magnetic component 3 can be replaced. If the magnetic flux of the first magnetic component 3 is greater than or equal to the first preset magnetic flux threshold, the step of setting the first magnetic component 3 on the side of the positioning fixture 2 away from the waveguide bearing surface can be performed. If the magnetic flux of the second magnetic component 4 is less than the second preset magnetic flux threshold, a new second magnetic component 4 can be replaced. If the magnetic flux of the second magnetic component 4 is greater than or equal to the second preset magnetic flux threshold, the step of covering the grating structure area of ​​the waveguide 1 to be coated with a second magnetic component 4 with a magnetic polarity opposite to that of the first magnetic component 3 can be performed.

[0072] The first preset magnetic flux threshold is used as the basis for determining whether the magnetic flux of the first magnetic component is sufficient. It can be a default value or can be flexibly set by the user according to the actual situation. This embodiment does not make specific limitations on this. The second preset magnetic flux threshold is used as the basis for determining whether the magnetic flux of the second magnetic component is sufficient. It can be a default value or can be flexibly set by the user according to the actual situation. This embodiment does not make specific limitations on this.

[0073] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0074] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0075] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent scope of this application.

Claims

1. A coating method for a diffractive optical waveguide, characterized in that, The method includes: The waveguide to be coated is placed on the waveguide bearing surface of the positioning fixture, and a first magnetic element is provided on the side of the positioning fixture away from the waveguide bearing surface. A grating structure region positioning fixture is placed on the coating surface of the waveguide to be coated. The grating structure region positioning fixture has at least one cutout window. The cutout window is shaped like the grating structure region. The frame of the grating structure region positioning fixture is pressed on the non-grating area of ​​the waveguide to be coated. The cutout window exposes the grating structure region relative to the surrounding non-grating area. After exposing the grating structure region, a second magnetic element with the opposite magnetic polarity to the first magnetic element is covered on the grating structure region of the waveguide to be coated, so as to adsorb and fix the grating structure region and the waveguide to be coated based on the magnetic force between the first magnetic element and the second magnetic element. Remove the grating structure area positioning fixture placed on the surface to be coated; A coating is applied to the surface of the waveguide to be coated to form an antireflection coating in the non-grating region of the waveguide.

2. The method as described in claim 1, characterized in that, The waveguide to be coated is provided with a first positioning part, and the step of placing the grating structure region positioning fixture on the coating surface of the waveguide to be coated includes: A second positioning part matching the first positioning part is provided on the positioning fixture of the grating structure area; The first positioning part and the second positioning part are aligned and matched to place the grating structure area positioning fixture on the coating surface of the waveguide to be coated.

3. The method as described in claim 1, characterized in that, After the step of placing the grating structure region positioning fixture on the coating surface of the waveguide to be coated, the method further includes: The positioning fixture for the grating structure area is fixedly connected to the locking fixture by a fastener; Before the step of removing the positioning fixture for the grating structure area placed on the surface to be coated, the method further includes: Remove the fixing piece from the positioning fixture of the grating structure area.

4. The method as described in claim 1, characterized in that, Before the step of covering the grating structure region of the waveguide to be coated with a second magnetic element having a magnetic polarity opposite to that of the first magnetic element, the method further includes: A protective element is provided on the magnetic element covering surface of the grating structure region, and after the protective element is provided, the step of covering the grating structure region of the waveguide to be coated with a second magnetic element with a magnetic polarity opposite to that of the first magnetic element is performed.

5. The method according to any one of claims 1 to 4, characterized in that, Before the step of placing the waveguide to be coated onto the waveguide bearing surface of the positioning fixture, the method further includes: Obtain waveguide bearing dimensions that match the external dimensions of the waveguide to be coated; The size of the waveguide bearing area on the waveguide bearing surface of the positioning fixture is adjusted to the waveguide bearing size, and after adjustment, the step of placing the waveguide to be coated on the waveguide bearing surface of the positioning fixture is performed.

6. The method according to any one of claims 1 to 4, characterized in that, The method further includes: In the case of multiple waveguides to be coated, the first target size of the positioning fixture and the second target size of each waveguide bearing area on the waveguide bearing surface of the positioning fixture are determined according to the external dimensions of each waveguide to be coated. The dimensions of the positioning fixture are adjusted to the first target dimensions, and the dimensions of each waveguide bearing area in the positioning fixture are adjusted to their respective second target dimensions.

7. The method as described in claim 6, characterized in that, The step of determining the first target size of the positioning fixture and the second target size of each waveguide bearing area on the waveguide bearing surface of the positioning fixture based on the external dimensions of each of the waveguides to be coated includes: Obtain waveguide bearing dimensions that match the external dimensions of each of the waveguides to be coated, and use them as the second target dimensions of the bearing regions of each of the waveguides; The first target size of the positioning fixture is determined based on the second target size of each waveguide bearing region and the layout position of each waveguide bearing region on the positioning fixture.

8. The method according to any one of claims 1 to 4, characterized in that, Before the step of coating the surface of the waveguide to be coated, the method further includes: The positioning fixture and the waveguide to be coated are flipped so that the coating surface is facing down. An image of the second magnetic component covering the grating structure area is acquired using an image acquisition device; Based on the image, determine whether the second magnetic component completely covers the grating structure area; If so, then perform the step of coating the surface of the waveguide to be coated; If not, adjust the coverage position of the second magnetic element in the grating structure area, and return to the step of acquiring the image of the second magnetic element from bottom to top using the image acquisition device.

9. The method according to any one of claims 1 to 4, characterized in that, Before the step of coating the surface of the waveguide to be coated, the method further includes: The magnetic force between the first magnetic component and the second magnetic component is collected by a pressure sensor; Determine whether the magnetic force is greater than or equal to a preset magnetic force threshold; If so, then perform the step of coating the surface of the waveguide to be coated; If not, replace the first magnetic component and / or the second magnetic component, and return to the step of determining whether the magnetic force is greater than the preset magnetic force threshold.

Images