A diffractive optical waveguide and augmented reality display device

Abstract

This invention provides a diffractive optical waveguide, comprising a waveguide sheet with a diffractive optical structure region; a protective sheet disposed opposite to the side of the waveguide sheet with the diffractive optical structure region; and a sealant layer located between the waveguide sheet and the protective sheet, the sealant layer being situated at the edges of the waveguide sheet and the protective sheet, with the diffractive optical structure region situated within the area enclosed by the sealant layer. The sealant layer includes an outer adhesive line, an inner adhesive body, and a sealing adhesive body. The outer adhesive line is arranged in a ring along the inner edge of the waveguide sheet, with openings at both ends. The inner adhesive body is located inside the openings and has a gap with the outer adhesive line, the length of the inner adhesive body being greater than or equal to the opening size. The sealing adhesive body fills the openings and the gaps between the outer adhesive line and the inner adhesive body. This invention enables the expulsion of air from the sealant layer during the pressing process of the waveguide sheet and the protective sheet, balancing the internal air pressure and effectively preventing external foreign matter from entering the waveguide sheet and causing contamination.

Description

Technical Field

[0001] This utility model relates to the field of optical technology, and in particular to a diffractive waveguide and an augmented reality display device. Background Technology

[0002] The core component of augmented reality display devices is the diffractive waveguide. The diffractive waveguide relies on the diffractive optical structure region on the waveguide sheet to achieve light manipulation and image output. To protect the diffractive optical structure region, optically transparent resin (OCR) adhesive is commonly used in the market, and the waveguide sheet and protective sheet are bonded together using a frame bonding technique.

[0003] However, if a completely sealed, closed-loop adhesive line is used for encapsulation during the dispensing and bonding process, the air trapped inside the adhesive line cannot be effectively released. This results in residual air pressure inside after pressing and curing, causing micro-deformation of the diffractive waveguide. Furthermore, at high temperatures, there is a risk of adhesive delamination. Conversely, if an open-loop adhesive line design is used to release internal air pressure during dispensing and bonding, its compatibility in certain environments will be significantly reduced. Foreign particles can easily enter the diffractive waveguide, severely impacting its lifespan. Utility Model Content

[0004] This invention provides a diffractive waveguide and an augmented reality display device that balances the airtightness of the sealant layer and the internal air pressure balance, effectively reducing the risk of foreign objects entering the diffractive waveguide and changes in the parallelism of the diffractive waveguide.

[0005] In a first aspect, this utility model provides a diffractive optical waveguide, comprising:

[0006] A waveguide sheet, wherein at least one side surface of the waveguide sheet is provided with a diffractive optical structure region;

[0007] A protective sheet is disposed opposite to the waveguide sheet on the side where the waveguide sheet has a diffraction optical structure region.

[0008] A sealant layer is provided, located between the waveguide sheet and the protective sheet, at the edges of the waveguide sheet and the protective sheet, with the diffractive optical structure region situated within the area enclosed by the sealant layer; wherein,

[0009] The sealing adhesive layer includes an outer adhesive line, an inner adhesive body, and a sealing adhesive body; the outer adhesive line is arranged in a ring along the inner edge of the waveguide sheet, and the two ends of the outer adhesive line form openings; the inner adhesive body is located inside the opening and has a gap with the outer adhesive line; the length of the inner adhesive body is greater than or equal to the size of the opening; the sealing adhesive body fills the opening and the gap between the outer adhesive line and the inner adhesive body.

[0010] Optionally, the distance between the opening and the diffractive optical structure region is greater than the distance between each part of the outer adhesive line and the diffractive optical structure region.

[0011] Optionally, the diffractive optical structure region includes a coupled optical element;

[0012] The opening is located near the coupled optical element, the inner colloid is located between the opening and the coupled optical element, and there is a gap between the inner colloid and the coupled optical element.

[0013] Optionally, in the outer adhesive line, the width of the adhesive line near the beginning and end of the outer adhesive line is smaller than the width of the adhesive line away from the beginning and end of the outer adhesive line.

[0014] Optionally, the inner adhesive includes an inner adhesive line, which is an arc, and the arc either convexes outward toward the opening or is recessed toward the opening.

[0015] Optionally, the inner adhesive includes an inner adhesive line, which is a straight line. The straight line is parallel to the line connecting the beginning and end of the outer adhesive line, or the straight line forms an angle with the extension of the line connecting the beginning and end of the outer adhesive line.

[0016] Optionally, the inner colloid includes a plurality of glue dots arranged in sequence, and the arrangement trajectory of the plurality of glue dots is a straight line or an arc.

[0017] Optionally, the sealant layer further includes two adhesive dots;

[0018] The adhesive dot is located in the gap between the outer adhesive line and the inner adhesive body, and has a gap between itself and the outer adhesive line and the inner adhesive body, respectively.

[0019] The two adhesive dots are located on either side of the line connecting the center of the opening and the center of the inner adhesive.

[0020] In a second aspect, the present invention provides an augmented reality display device, including a diffractive waveguide as described in any of the first aspects.

[0021] Optionally, the augmented reality display device is augmented reality glasses or an augmented reality head-up display.

[0022] The diffractive waveguide and augmented reality display device provided by this invention, by setting an opening on the outer adhesive line and setting an inner adhesive inside the opening with a gap between the inner adhesive and the outer adhesive line, allows air inside the sealing adhesive layer to be discharged in time during the pressing process of the waveguide sheet and the protective sheet, thus balancing the internal air pressure and avoiding problems such as bulging of the sealing adhesive layer caused by residual internal air pressure. This improves the bonding yield and the stability of optical performance. In addition, after pressing, sealing adhesive is filled into the opening and the gap between the inner adhesive and the outer adhesive line, so that the sealing adhesive, together with the outer adhesive line and the inner adhesive, forms a sealed adhesive line, effectively preventing foreign objects from entering the interior of the diffractive waveguide and causing contamination of the diffractive optical structure area.

[0023] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A top view of a diffractive optical waveguide provided for an embodiment of this utility model;

[0026] Figure 2 A cross-sectional view of a diffractive optical waveguide provided for an embodiment of this utility model;

[0027] Figure 3 for Figure 1 A magnified view of a section at point A in the middle;

[0028] Figure 4 A top view of another diffractive waveguide provided in an embodiment of this utility model;

[0029] Figure 5 A cross-sectional view of another diffractive waveguide provided in an embodiment of this utility model;

[0030] Figure 6 for Figure 4 A magnified view of a section at point E in the middle;

[0031] Figure 7 A top view of yet another diffractive waveguide provided in an embodiment of this utility model;

[0032] Figure 8A cross-sectional view of another diffractive waveguide provided in an embodiment of this utility model;

[0033] Figure 9 for Figure 7 A magnified view of a section at point B in the middle;

[0034] Figure 10 A top view of yet another diffractive waveguide provided in an embodiment of this utility model;

[0035] Figure 11 for Figure 10 A magnified view of a section at point C;

[0036] Figure 12 A top view of yet another diffractive waveguide provided in an embodiment of this utility model;

[0037] Figure 13 for Figure 12 A magnified view of a section at point D;

[0038] Figure 14 A schematic diagram of another diffractive waveguide provided in this embodiment of the present invention;

[0039] Figure 15 for Figure 14 A magnified view of a section at point F. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] Figure 1 This is a top view of a diffractive optical waveguide provided in an embodiment of the present invention. Figure 2 A cross-sectional view of a diffractive waveguide provided for an embodiment of this utility model, as shown below. Figure 1 and Figure 2 As shown, the diffractive waveguide includes a waveguide sheet 10, a sealant layer 20, and a protective sheet 30. At least one surface of the waveguide sheet 10 has a diffractive optical structure region 60. The protective sheet 30 is disposed opposite to the side of the waveguide sheet 10 with the diffractive optical structure region 60. The sealant layer 20 is located between the waveguide sheet 10 and the protective sheet 30, at the edge of both sheets. The diffractive optical structure region 60 is located within the area enclosed by the sealant layer 20. The sealant layer 20 includes an outer adhesive line 201, an inner adhesive body 202, and a sealing adhesive (not shown). The outer adhesive line 201 is arranged in a ring along the inner edge of the waveguide sheet 10, with openings 2011 formed at both ends. The inner adhesive body 202 is located inside the openings 2011 and has a gap with the outer adhesive line 201. The length of the inner adhesive body 202 is greater than or equal to the size of the openings 2011. The sealing adhesive fills the gap between the opening 2011 and the outer adhesive line 201 and the inner adhesive 202.

[0043] Specifically, a waveguide sheet 10, a sealant layer 20, and a protective sheet 30 are stacked. At least one surface of the waveguide sheet 10 has a diffraction optical structure region 60. The protective sheet 30 is disposed opposite to the side of the waveguide sheet 10 with the diffraction optical structure region 60. The sealant layer 20 is located between the waveguide sheet 10 and the protective sheet 30, and is used to bond the waveguide sheet 10 and the protective sheet 30. (Reference) Figure 1 The sealant layer 20 is located at the edge of the waveguide sheet 10 and the protective sheet 30, and the diffraction optical structure region 60 is located within the area enclosed by the sealant layer 20. The sealant layer 20 includes an outer adhesive line 201, an inner adhesive 202, and a sealing adhesive (not shown in the figure). When drawing the outer adhesive line 201 on the waveguide sheet 10, the outer adhesive line 201 can be designed to conform to the edge shape of the waveguide sheet 10 and be recessed inward relative to the edge of the waveguide sheet 10 by a certain distance, so that after the waveguide sheet 10 and the protective sheet 30 are pressed together, the outer edge of the outer adhesive line 201 can be flush with the edge of the waveguide sheet 10. In addition, the width of the outer adhesive line 201 after pressing can be controlled by changing the amount of adhesive applied. Optionally, the width of the outer adhesive line 201 after pressing can be 0.7mm-1.2mm. For example, if the width of the outer adhesive line 201 after pressing is 0.7 mm, then when drawing the outer adhesive line 201, the outer adhesive line 201 should be recessed by 0.35 mm relative to the edge of the waveguide sheet 10.

[0044] Furthermore, when drawing the outer adhesive line 201, the outer adhesive line 201 is arranged in a ring along the inner edge of the waveguide sheet 10, and openings 2011 are formed at both ends of the outer adhesive line 201. During the pressing process of the waveguide sheet 10 and the protective sheet 30, the openings 2011 help to timely expel the air inside the outer adhesive line 201, so as to balance the internal air pressure. Optionally, the length of the opening 2011 is less than or equal to 1 mm.

[0045] Further, refer to Figure 1 The inner adhesive 202 is located inside the opening 2011 and has a gap with the outer adhesive line 201. This allows air inside the inner adhesive 202 and the outer adhesive line 201 to escape through the gaps at both ends of the inner adhesive 202 during the bonding process of the waveguide sheet 10 and the protective sheet 30. This ensures stable air pressure inside and outside the outer adhesive line 201 and the inner adhesive 202, reduces the impact force on the outer adhesive line 201 and the inner adhesive 202 during bonding, and avoids problems such as bulging, wavy, and deformed sealing adhesive layer 20 caused by residual air pressure inside. This improves the bonding yield and the stability of optical performance. Optionally, the width of the inner adhesive 202 can be 0.5mm-0.6mm.

[0046] Furthermore, the length of the inner colloid 202 is greater than or equal to the size of the opening 2011. After drawing the outer adhesive line 201 and the inner colloid 202 on the waveguide sheet 10, the protective sheet 30 is pressed together with the waveguide sheet 10. After pressing, in order to prevent dust particles in the air from entering the interior of the diffractive waveguide through the opening 2011 and the gap between the outer adhesive line 201 and the inner colloid 202, a glue filling machine can be used to fill the opening 2011 and the gap between the outer adhesive line 201 and the inner colloid 202 with sealing colloid (not shown in the figure).

[0047] Specifically, the pressed diffractive waveguide is placed vertically on the stage, with the opening 2011 aligned with the glue applicator. The glue applicator is perpendicular to the stage. Since the protective sheet 30 and waveguide sheet 10 of the diffractive waveguide have already been bonded and their parallelism is determined, a piezoelectric ceramic valve with relatively high positioning accuracy can be used for glue applicator application to improve the accuracy of glue applicator application. Simultaneously, the same microbead-free optically transparent adhesive (OCR) as the outer adhesive line 201 and inner adhesive 202 is used for glue applicator application to the opening 2011. Because the microbead-free optically transparent adhesive has good flowability, it can improve the efficiency of glue applicator application. Alternatively, an adhesive that does not react with the adhesive used for the outer adhesive line 201 and inner adhesive 202, and has a higher flowability than the adhesive used for the outer adhesive line 201 and inner adhesive 202, can also be used for glue applicator application. During the glue application process, the inner colloid 202 can intercept the glue, effectively preventing the glue from flowing into the diffractive waveguide and contaminating the diffractive optical structure region 60.

[0048] Furthermore, after the adhesive application is completed, the diffractive waveguide is held still for 3-5 seconds to ensure that the adhesive completely fills and cures the gaps between the opening 2011, the outer adhesive line 201, and the inner adhesive 202, thereby forming a sealing adhesive (shown in the figure). It is understood that at this point, the sealing adhesive (shown in the figure) forms a sealed sealing layer 20 with the outer adhesive line 201 and the inner adhesive 202, effectively preventing external foreign objects from entering the interior of the diffractive waveguide.

[0049] This embodiment of the invention provides an opening on the outer adhesive line and an inner adhesive layer inside the opening, with a gap between the inner adhesive layer and the outer adhesive line. This allows air inside the sealant layer to escape promptly during the bonding process of the waveguide sheet and the protective sheet, balancing the internal air pressure and preventing problems such as bulging of the sealant layer caused by residual internal air pressure. This improves the bonding yield and the stability of optical performance. Furthermore, after bonding, sealing adhesive is filled into the opening and the gap between the inner adhesive layer and the outer adhesive line, forming a sealed sealant layer together with the outer adhesive line and the inner adhesive layer. This effectively prevents external foreign matter from entering the diffractive waveguide and causing contamination of the diffractive optical structure region.

[0050] Optionally, Figure 3 for Figure 1 A magnified view of a portion of point A, as shown below. Figures 1-3 As shown, the opening 2011 is located at a position away from the diffraction optical structure region 60.

[0051] Specifically, such as Figure 1 As shown, the diffractive optical structure region 60 can be a grating region or a metasurface structure region; the diffractive optical structure region 60 includes an inserted optical element 40 and an exit optical element 50. The opening 2011 can be set at a position away from the inserted optical element 40 and the exit optical element 50. This can effectively prevent contamination of the inserted optical element 40 and the exit optical element 50 due to the inner adhesive 202 being too close to them. It can also prevent adhesive from flowing into the inserted optical element 40 and the exit optical element 50 during the adhesive application process.

[0052] Furthermore, in an optional embodiment, in order to reduce the width of the sealant layer 20 at the opening 2011, when drawing the outer sealant line 201, the width of the sealant line near the beginning and end of the outer sealant line 201 is smaller than the width of the sealant line away from the beginning and end of the outer sealant line 201.

[0053] Specifically, refer to Figure 3In the outer adhesive line 201, the width of the adhesive line near both ends of the outer adhesive line 201 can be L1, and the width of the adhesive line away from both ends of the outer adhesive line 201 can be L2, where L1 < L2. Furthermore, when reducing the width of the adhesive line at both ends of the outer adhesive line 201, the outer edge of the outer adhesive line 201 can be flush with the edge of the adjacent waveguide sheet 10, and the inner edge of the outer adhesive line 201 can be moved closer to the outer edge to reduce the width of the outer adhesive line 201. For example, the width of the adhesive line near both ends of the outer adhesive line 201 can be 0.5 mm, and the width of the adhesive line away from both ends of the outer adhesive line 201 can be 0.7 mm.

[0054] It should be noted that this is not intended to limit the embodiments of this utility model. When the opening 2011 is set at a position far away from the diffraction optical structure region 60, that is, the distance between the opening and the diffraction optical structure region is greater than the distance between each part of the outer adhesive line and the diffraction optical structure region, the width of the adhesive line at both ends near and far from the outer adhesive line 201 can be the same. In this case, the difficulty of drawing the outer adhesive line 201 can be reduced.

[0055] Furthermore, in another alternative embodiment, reference is made to... Figure 3 The inner colloid 202 includes an inner adhesive line, which is an arc. The arc either bulges outward toward the opening 2011 or is recessed toward the opening 2011.

[0056] Specifically, in order to further reduce the width of the sealant layer 20 at the opening 2011, refer to Figure 3 When drawing the inner adhesive 202, it can be made to bulge outward toward the opening 2011. When the width of the adhesive line near the beginning and end of the outer adhesive line 201 is reduced, the inner adhesive 202 can be drawn as close as possible to the edge of the waveguide sheet 10, thereby reducing the overall width of the sealing layer 20 at that location. For example, the distance between the inner edge of the inner adhesive 202 and the edge of the waveguide sheet 10 can be 0.7mm-1.2mm. Furthermore, to further reduce the width of the sealing layer 20 near the opening 2011, a portion of the inner adhesive 202 can bulge outward into the opening 2011.

[0057] This embodiment of the invention effectively avoids contamination of the coupling optical elements (optical elements) caused by the inner adhesive being too close to them, by designing the opening away from the coupling optical elements. It also prevents adhesive from flowing into the coupling optical elements during the application process. Furthermore, by reducing the width of the adhesive line near the beginning and end of the outer adhesive line, the inner adhesive can be closer to the edge of the waveguide sheet, thereby reducing the overall width of the sealing adhesive layer at the opening. This makes the design structure at the opening invisible to users of augmented reality display devices made using this diffractive waveguide, improving the aesthetics of the augmented reality display device.

[0058] It should be noted that the inner colloid 202 can also be recessed towards the opening 2011. In this case, the inner colloid 202 can effectively receive the glue in the subsequent glue application process, preventing the inside of the diffractive waveguide from being contaminated. Figure 4 This is a top view of another diffractive waveguide provided in an embodiment of the present invention. Figure 5 A cross-sectional view of another diffractive waveguide provided in an embodiment of this utility model. Figure 6 for Figure 4 A magnified view of a section at point E, as shown below. Figure 4 , Figure 5 and Figure 6 As shown, the inner colloid 202 includes an inner adhesive line, which is an arc and is recessed toward the opening 2011.

[0059] Specifically, when drawing the inner colloid 202, the inner colloid 202 can be extended along an arc, with the arc concave towards the opening 2011, presenting a shape that bends inward from the middle and outward from both sides. The length of the inner colloid 202 is greater than the length of the opening 2011. At this time, during the glue application process, the inner colloid 202 will receive the glue, thereby preventing the glue from overflowing into the diffraction waveguide. At this time, the distance between the edge of the coupled optical element 40 and the edge of the waveguide sheet 10 is 1.5mm-2.0mm. After pressing, the distance between the inner edge of the inner colloid 202 and the edge of the waveguide sheet 10 is 1.2mm-1.7mm.

[0060] This utility model embodiment sets the inner colloid in a concave shape toward the opening, so that the glue used in the glue application process can be received by the inner colloid alone.

[0061] Optionally, Figure 7 A top view of yet another diffractive waveguide provided in an embodiment of this utility model. Figure 8 A cross-sectional view of another diffractive waveguide provided in an embodiment of this utility model. Figure 9 for Figure 7 A magnified view of a section at point B, as shown below. Figure 7 , Figure 8 and Figure 9 As shown, the diffractive optical structure region 60 of the waveguide sheet 10 includes an input optical element 40 and an output optical element 50. An opening 2011 is disposed near the input optical element 40, and an inner colloid 202 is located between the opening 2011 and the input optical element 40, with a gap between the inner colloid 202 and the input optical element 40.

[0062] Specifically, when drawing the outer adhesive line 201, the opening 2011 can be set between the edges of the coupled optical element 40 and the nearest waveguide sheet 10 of the coupled optical element 40. This allows the opening 2011 to be within the optical engine coverage area in the augmented reality display device made using this diffractive waveguide, thereby making the opening 2011 invisible to the eye, improving the overall aesthetics of the augmented reality display device, and without obstructing the visual area.

[0063] Further, in an alternative embodiment, reference is made to... Figure 9 When drawing the inner colloid 202 between the opening 2011 and the coupled optical element 40, the inner colloid 202 includes an inner colloid line, which is an arc line that convexes outward toward the opening 2011 or is recessed toward the opening 2011.

[0064] Specifically, since the distance between the opening 2011 and the coupled optical element 40 is small, the inner adhesive 202 can bulge outward toward the opening 2011, making it bend parallel to the edge of the coupled optical element 40, thereby expanding the drawing area of ​​the inner adhesive 202. Furthermore, the length of the inner adhesive 202 can be greater than the length of the opening 2011, thus preventing adhesive from flowing into the coupled optical element 40 during subsequent adhesive application. For example, the opening 2011 can be provided at a position 1.5mm-2.0mm from the edge of the coupled optical element 40 at the edge of the waveguide 10, so the distance between the inner edge of the inner adhesive 202 and the edge of the waveguide 10 after pressing can be 1.2mm-1.7mm. The length of the inner adhesive 202 can be set to be approximately 2mm longer than the length of the opening 2011.

[0065] Furthermore, in another alternative embodiment, Figure 10 A top view of yet another diffractive waveguide provided in an embodiment of this utility model. Figure 11 for Figure 10 A magnified view of a section at point C. Figure 12 A top view of yet another diffractive waveguide provided in an embodiment of this utility model. Figure 13 for Figure 12 A magnified view of a section at point D, as shown below. Figures 10-13As shown, the inner adhesive 202 includes an inner adhesive line, which is a straight line. The straight line is parallel to the line connecting the beginning and end of the outer adhesive line 201, or the straight line forms an angle with the extension of the line connecting the beginning and end of the outer adhesive line 201.

[0066] Specifically, refer to Figure 10 and Figure 11 The inner colloid 202 can also extend along a straight line, and the straight line is parallel to the line connecting the beginning and end of the outer colloid line 201, reducing the difficulty of drawing the inner colloid 202. Furthermore, refer to... Figure 12 and Figure 13 When the inner colloid 202 extends in a straight line, the straight line can also form an angle with the extension of the line connecting the two ends of the outer colloid 201. That is, one end of the inner colloid 202 is close to the opening 2011, while the other end is far away from the opening 2011. However, as a whole, the inner colloid 202 is still located between the opening 2011 and the coupled optical element 40, and has gaps with both the opening 2011 and the coupled optical element 40.

[0067] It is worth mentioning that when the opening 2011 is located near the coupled optical element 40, the inner colloid 202 can also be recessed towards the opening 2011. In this case, the inner colloid 202 can effectively receive the glue in the subsequent glue application process, preventing contamination inside the diffractive waveguide. This is not intended to limit the embodiments of this utility model. Furthermore, when the opening 2011 is located away from the diffractive optical structure region 60, the inner colloid 202 can also be a straight line, and the straight line is parallel to the line connecting the beginning and end of the outer glue line 201, or the straight line forms an angle with the extension line connecting the beginning and end of the outer glue line 201. This is not intended to limit the embodiments of this utility model.

[0068] This embodiment of the invention places the opening near the coupled optical element, so that in the augmented reality display device made using the diffractive waveguide, the opening is within the optical engine coverage area, thereby making the opening invisible to the eye, improving the overall aesthetics of the augmented reality display device, and without obstructing the visual area.

[0069] Optionally, Figure 14 This is a schematic diagram of another diffractive waveguide provided in an embodiment of the present invention. Figure 15 for Figure 14 A magnified view of a section at point F, as shown below. Figure 14 and Figure 15 As shown, the inner colloid 202 includes multiple glue dots arranged sequentially, and the arrangement trajectory of the multiple glue dots is a straight line or an arc. (Reference) Figure 14 and Figure 15When the inner adhesive 202 consists of multiple sequentially arranged adhesive dots, venting holes can be added during the pressing process of the protective sheet 30 and the waveguide sheet 10, allowing air inside the sealing adhesive layer 20 to escape more smoothly and achieving internal air pressure balance. It is worth mentioning that, in Figures 1-13 In the embodiments shown, the inner colloid 202 can be multiple glue dots arranged in sequence, which is not intended to limit the embodiments of this utility model.

[0070] Optionally, refer to Figures 1-3 and Figures 7-13 The sealant layer 20 also includes two adhesive dots 203. The adhesive dots 203 are located in the gap between the outer adhesive line 201 and the inner adhesive 202, and have gaps between them respectively; the two adhesive dots 203 are located on both sides of the line connecting the center of the opening 2011 and the center of the inner adhesive 202.

[0071] Specifically, to prevent adhesive from entering the interior of the diffractive waveguide during the application process and causing contamination of the diffractive optical structure region 60, refer to... Figures 1-3 and Figures 7-13 When drawing the outer adhesive line 201 and the inner adhesive 202, two adhesive dots 203 are added. The adhesive dots 203 are located in the gap between the outer adhesive line 201 and the inner adhesive 202, and there are gaps between them and the outer adhesive line 201 and the inner adhesive 202, respectively. This ensures that the adhesive dots 203 do not contact the outer adhesive line 201 and the inner adhesive 202 during the pressing process, so that the air in the outer adhesive line 201 and the inner adhesive 202 can be discharged from the gap.

[0072] Furthermore, the adhesive dot 203 is located in the gap between the outer adhesive line 201 and the inner adhesive 202. During the adhesive application process, after the adhesive drips into the opening 2011, it flows along the inner adhesive 202 into the gap between the outer adhesive line 201 and the inner adhesive 202. Placing the adhesive dot 203 at this location effectively prevents the adhesive from entering the diffractive waveguide through the gap. For example, the diameter of the adhesive dot after pressing can be less than or equal to 0.5 mm.

[0073] Optionally, this utility model embodiment provides an augmented reality display device, including any of the diffractive waveguides described above, wherein the augmented reality display device is augmented reality glasses or an augmented reality head-up display device.

[0074] In summary, the diffractive waveguide provided in this embodiment occupies a small area for the adhesive filling opening. Therefore, when this diffractive waveguide is applied to an augmented reality display device, the opening can be placed within the area covered by the edge of the coupled optical element or other equipment, ensuring that the opening is not visually visible. This not only improves aesthetics but also avoids obstructing the visual area. Furthermore, because the adhesive filling opening area is small, it also occupies less space at the edges of the waveguide sheet and the protective sheet, resulting in a relatively smaller distance from the edge of the waveguide sheet to the coupled optical element. Ultimately, this achieves the goal of reducing the overall size of the augmented reality display device.

[0075] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A diffractive optical waveguide, characterized in that, include: A waveguide sheet, wherein at least one side surface of the waveguide sheet is provided with a diffractive optical structure region; A protective sheet is disposed opposite to the side of the waveguide sheet where the diffraction optical structure region is located. A sealant layer is provided, located between the waveguide sheet and the protective sheet, at the edges of the waveguide sheet and the protective sheet, with the diffractive optical structure region situated within the area enclosed by the sealant layer; wherein, The sealing adhesive layer includes an outer adhesive line, an inner adhesive body, and a sealing adhesive body; the outer adhesive line is arranged in a ring along the inner edge of the waveguide sheet, and the two ends of the outer adhesive line form openings; the inner adhesive body is located inside the opening and has a gap with the outer adhesive line; the length of the inner adhesive body is greater than or equal to the size of the opening; the sealing adhesive body fills the opening and the gap between the outer adhesive line and the inner adhesive body.

2. The diffractive waveguide according to claim 1, characterized in that, The distance between the opening and the diffractive optical structure region is greater than the distance between each part of the outer adhesive line and the diffractive optical structure region.

3. The diffractive waveguide according to claim 1, characterized in that, The diffractive optical structure region includes coupled optical elements; The opening is located near the coupled optical element, the inner colloid is located between the opening and the coupled optical element, and there is a gap between the inner colloid and the coupled optical element.

4. The diffractive waveguide according to any one of claims 1-3, characterized in that, In the outer adhesive line, the width of the adhesive line near the beginning and end of the outer adhesive line is smaller than the width of the adhesive line away from the beginning and end of the outer adhesive line.

5. The diffractive waveguide according to any one of claims 1-3, characterized in that, The inner adhesive includes an inner adhesive line, which is an arc, and the arc either bulges outward toward the opening or is recessed toward the opening.

6. The diffractive waveguide according to any one of claims 1-3, characterized in that, The inner adhesive includes an inner adhesive line, which is a straight line. The straight line is parallel to the line connecting the beginning and end of the outer adhesive line, or the straight line forms an angle with the extension of the line connecting the beginning and end of the outer adhesive line.

7. The diffractive waveguide according to any one of claims 1-3, characterized in that, The inner colloid comprises multiple glue dots arranged sequentially, with the arrangement trajectory of the multiple glue dots being a straight line or an arc.

8. The diffractive waveguide according to any one of claims 1-3, characterized in that, The sealant layer also includes two adhesive dots; The adhesive dot is located in the gap between the outer adhesive line and the inner adhesive body, and has a gap between itself and the outer adhesive line and the inner adhesive body, respectively. The two adhesive dots are located on either side of the line connecting the center of the opening and the center of the inner adhesive.

9. An augmented reality display device, characterized in that, Including the diffractive waveguide as described in any one of claims 1-8.

10. The augmented reality display device according to claim 9, characterized in that, The augmented reality display device is augmented reality glasses or an augmented reality head-up display.

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