Diffraction optical waveguide lens and preparation method thereof

Abstract

The present invention relates to the field of augmented reality technology, and in particular to a diffractive optical waveguide lens and a preparation method thereof, comprising: at least one stacked cover plate and at least one waveguide substrate; a first surface of the cover plate and a second surface opposite to the first surface; a flexible transparent member of a certain thickness disposed on the second surface and / or a grating structure; the contact angle of the flexible transparent member being greater than or equal to a preset value to prevent adhesion between the cover plate and the grating or waveguide substrate; the flexible transparent member being able to reduce adhesion to other surfaces when in contact with the other surfaces, thereby preventing adhesion or linkage between the cover plate and the waveguide when the cover plate contacts the waveguide during the application of force, ensuring consistency of the gap before and after deformation and the imaging effect, enabling the reuse of the diffractive optical waveguide lens, improving the imaging effect, achieving a better display effect, and ensuring imaging quality before and after use.

Description

Technical Field

[0001] The present invention relates to the field of augmented reality technology, and in particular to a diffraction light waveguide lens and a preparation method thereof. Background Art

[0002] Augmented reality technology is a fusion technology that seamlessly connects the real world and the virtual world. Through computer simulation and optical projection, the pixels of the optical machine are projected into the real world, realizing the real-time organic fusion of the real environment and virtual objects.

[0003] Optical waveguides are crucial for implementing augmented reality (AR) technology. Achieving lossless light transmission within waveguides is a pressing challenge. When AR waveguides are used, they inevitably come into contact with the environment. Dust, volatile organic compounds (VOCs), and inorganic substances can easily accumulate on the waveguide surface, forming stains that deflect light entering the eye and affect imaging. Dust, VOCs, and other contaminants often need to be wiped clean from the waveguide surface. This process, when applied or worn, inevitably exerts force on the waveguide surface. Due to the gap between the waveguide substrate and the cover plate, the force applied to the cover plate can easily cause the cover plate and waveguide substrate to bend and deform, resulting in Newton rings. This can affect imaging and severely degrade image quality.

[0004] The prior art publication number CN215932334U discloses a lens assembly and glasses, wherein a first spacer 60 is provided in a first space 30a. The first spacer 60 is used to support the electrochromic element 30. When the electrochromic element 30 is bent and deformed toward the optical waveguide 20 under force, the electrochromic element 30 contacts the optical waveguide 20 and a Newton's ring phenomenon occurs (see paragraph 0057 of the specification). The first spacer 60 is an elastic structure or is made of PET material (see paragraphs 0059-0061 of the specification). This method can alleviate the Newton's ring phenomenon to a certain extent, but there are some problems in the process of setting the first spacer. The technical problem of how to set the position of the spacer, how to fix the spacer, and how to select the material of the spacer so that it does not affect the performance of the optical waveguide and thus does not affect the imaging visual effect is a great challenge for those skilled in the art. This technical solution has high requirements for the selection and installation position setting of the spacer, which is difficult to achieve with ordinary processes. In this solution, how to set the spacer so that it does not affect the grating structure or reduces the impact on the grating structure is a great challenge and difficult to solve. Furthermore, the setting of such a first spacer makes it visually unsightly during wearing. The spacer is visible to the naked eye and affects the visual effect. Therefore, this solution has many problems. For those skilled in the art, how to solve the Newton ring phenomenon between the cover plate and the optical waveguide caused by wiping or wearing is an urgent problem that needs to be solved. Summary of the Invention

[0005] In order to make up for the shortcomings of the existing technology, the present application provides a diffraction light waveguide lens, which can solve the Newton ring phenomenon caused by deformation and bending between the cover plate and the waveguide substrate due to the force applied during wiping or wearing. The diffraction light waveguide lens of the present invention can improve the strength of the lens by depositing material on the surface of the cover plate or directly pasting a molded flexible transparent part and / or depositing material on the grating structure. It is easy to process and flexible and convenient to use, has a simple process, strong applicability, is overall beautiful and flawless during use, has a good field of view effect, and has an explosion-proof function.

[0006] The technical solution of the present invention is:

[0007] A diffraction light waveguide lens, characterized by comprising: at least one stacked cover plate and at least one waveguide substrate; a grating structure provided on at least one side of the waveguide substrate; the cover plate having a first surface remote from the grating structure and a second surface adjacent to the grating structure and opposite to the first surface; a flexible transparent member of a certain thickness provided on the second surface and / or the grating structure, and the surface of the flexible transparent member being flattened; the flexible transparent member at least partially covering the grating structure; and a contact angle of the flexible transparent member being greater than or equal to a preset value to prevent adhesion between the cover plate and the grating or waveguide substrate.

[0008] In some embodiments, the thickness of the flexible transparent member is uniform and completely covers the grating structure; or the thickness of the flexible transparent member is non-uniform and partially covers the grating structure.

[0009] Furthermore, a flexible transparent member is also provided on the first surface of the cover plate, and the thickness of the flexible transparent member on the first surface and the flexible transparent member on the second surface are the same or different.

[0010] In some embodiments, the contact angle of the flexible transparent member is greater than or equal to 90°.

[0011] Furthermore, in some embodiments, the flexible transparent member is an ultra-micro-nanostructure layer.

[0012] Furthermore, the flexible transparent member is composed of a material having two functional groups: low surface energy fluorinated groups and surface reactive groups.

[0013] Furthermore, when the organic fluoride contacts the surface material of the flexible substrate, the surface reactive groups will chemically react with the corresponding surface functional groups, generate chemical bonds on the surface of the cover plate, and then form a flexible transparent part of a certain thickness.

[0014] Furthermore, in some embodiments, the flexible transparent member is deposited on the second surface and / or the grating structure by magnetron sputtering or evaporation.

[0015] Furthermore, a flexible transparent material is deposited on a flexible substrate, and the flexible substrate is attached to the first surface and / or the second surface. The flexible substrate can be a commonly used material in the art that has functions such as electrochromic and explosion-proof.

[0016] Furthermore, before the flexible transparent member is formed, a layer of AR film is preferentially deposited on the first surface and / or the second surface.

[0017] Furthermore, the cover plate is made of glass, PE or other resin.

[0018] Furthermore, a black waterproof and breathable adhesive material is coated on the side edges of the at least one cover plate and / or the at least one waveguide substrate; the transmittance of the black waterproof and breathable adhesive material is ≤0.1%.

[0019] Furthermore, the present invention seeks protection for an augmented reality display device based on a waveguide, wherein the waveguide is a diffraction light waveguide lens.

[0020] Furthermore, the display device is a head-mounted device or HUD.

[0021] The principle of the present invention is as follows: by controlling the contact angle of the flexible transparent member, a suitable flexible transparent member material is selected within a certain angle range and arranged on the second surface of the cover plate and / or the grating structure. When the flexible transparent member on the cover plate contacts other surfaces, the adhesion to other surfaces can be reduced. When force is applied to the cover plate, the flexible transparent member can prevent adhesion or connection between the cover plate and the waveguide or waveguide substrate. Then, through the self-restoring force of the cover plate or substrate, the cover plate and the waveguide can be quickly restored to maintain the original gap between the two and return to the original state, thereby ensuring the imaging effect and preventing the imaging quality of the optical waveguide lens from deteriorating during multiple uses. It ensures that the user can always maintain the original performance of the optical waveguide when wiping surface stains or wearing it, improves the imaging quality of the optical waveguide, and realizes the reuse of the optical waveguide. This method has a wide application and certain economic benefits.

[0022] At the same time, the present invention provides a method for preparing a diffraction light waveguide lens, characterized in that at least one waveguide substrate is provided, and a grating structure is provided on at least one side of the waveguide substrate; at least one cover plate is provided, the cover plate having a first surface and a second surface opposite to the first surface, and a flexible transparent member of a certain thickness is respectively provided on the first surface, the second surface and at least one of the grating structure of the cover plate, the flexible transparent member at least partially covers the grating structure, and the contact angle of the flexible transparent member is greater than or equal to a preset value to prevent adhesion between the cover plate and the grating or waveguide substrate; further, when the flexible transparent member is provided on the first surface and / or the second surface of the cover plate, the side of the cover plate having the flexible transparent member is directed toward the grating structure and formed on the grating structure to obtain the diffraction light waveguide lens; and / or; when the flexible transparent member is provided on the grating structure, either side of the cover plate is directed toward the grating structure and formed on the grating structure to obtain the diffraction light waveguide lens.

[0023] Beneficial effects of the present invention:

[0024] The diffraction light waveguide lens provided by the present invention is configured by adding a flexible transparent member between the second surface of the cover plate and the grating structure. Of course, the position of the surface on which the flexible transparent member is located is not limited, and it can be on the second surface of the cover plate or on the grating structure, as long as the flexible transparent member can be ensured to be present between the two. When selecting the material of the flexible transparent member and conducting tests, flexible transparent members with different properties are prepared and tested for different contact angles. After multiple tests, it is verified that different flexible transparent members and contact angles of different flexible transparent members are selected based on various factors such as whether water droplets automatically slide off the cover plate surface when it is tilted and taking into account visual aesthetics. The flexible transparent members are preferably provided at different contact angles according to the contact angle between the cover plate and the waveguide. The recovery of the gap and the frequency of Newton rings have been studied. Numerous tests have shown that when the contact angle of the flexible transparent member is greater than or equal to 90°, the flexible transparent member on the cover plate can reduce its adhesion to other surfaces when in contact with the other surfaces. This can prevent the flexible transparent member between the cover plate and the waveguide substrate from sticking or connecting to each other when a force is applied. Furthermore, after the external force disappears, the relative position between the cover plate and the waveguide substrate can be restored to its original gap state, enabling the reuse of the diffraction light waveguide lens, improving the imaging effect, achieving a better display effect, and ensuring the image quality before and after use, with unexpected technical effects. By depositing material on the surface of the cover plate or directly attaching the formed flexible transparent member and / or depositing material on the grating structure, not only can the Newton ring phenomenon be reduced, but the overall strength of the lens can also be improved, providing an explosion-proof function, further preventing the lens from breakage to improve safety. Furthermore, the choice of deposition or direct attachment can be based on process costs (such as cost, ease of repair of the deposition, warping, etc.), which are not limited by the present invention. Furthermore, the black waterproof and breathable adhesive material can absorb edge stray light, thereby reducing the impact of stray light and improving display efficiency. Therefore, the above characteristics make the diffraction light waveguide lens provided by the present invention have unexpected technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the force acting on a diffraction light waveguide lens in the prior art;

[0026] Figure 2 A schematic structural diagram of a diffraction light waveguide lens provided in Example 1 of the present invention;

[0027] Figure 3 A schematic structural diagram of a diffraction light waveguide lens provided in the second embodiment of the present invention;

[0028] Figure 4 A schematic structural diagram of a diffraction light waveguide lens provided in Example 3 of the present invention;

[0029] Figure 5 This is a contact angle test diagram of different flexible transparent parts of the present invention. DETAILED DESCRIPTION

[0030] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below with reference to the accompanying drawings through specific embodiments. The scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art. The terms used in the specification are only for describing specific embodiments and should not be understood as limiting the present invention.

[0031] In an embodiment of the present invention, a diffractive optical waveguide lens is proposed to solve the technical problem in the prior art that, when a diffractive optical waveguide is used, bending deformation occurs between the cover plate and the waveguide substrate due to wiping or wearing, and Newton rings may occur between the cover plate and the optical waveguide during the deformation process, thereby affecting the imaging effect and causing a serious decline in imaging quality.

[0032] like Figure 1 As shown, the diffraction light waveguide lens 100 includes a cover plate 110, a grating structure 140, and a waveguide substrate 130; the cover plate 110 and the waveguide substrate 130 are connected by a sealant 120, and the grating structure 140 is provided on at least one side of the waveguide substrate 130; when wiping or wearing, the force applied to the cover plate 110 will easily cause bending deformation (such as Figure 1 As shown in FIG, a Newton ring phenomenon may occur between the cover plate 110 and the optical waveguide (a combination of the grating structure 140 and the waveguide substrate 130) during the deformation process, thereby affecting the imaging effect and causing a serious degradation in the imaging quality.

[0033] In order to solve the above problems, the first embodiment of the present invention is as follows: Figure 2 As shown, a diffraction optical waveguide lens 100 is provided, comprising a cover plate 110, a grating structure 140, and a waveguide substrate 130. The cover plate 110 and the waveguide substrate 130 are connected by a sealant 120, and the grating structure 140 is provided on at least one side of the waveguide substrate 130. The cover plate 110 has a first surface away from the grating structure and a second surface adjacent to the grating structure and opposite to the first surface. A flexible transparent member 210 of a certain thickness is provided on the second surface of the cover plate 110 and / or the grating structure, and the surface of the flexible transparent member 210 is flattened, and the flexible transparent member 210 partially covers the grating structure 140. The contact angle of the flexible transparent member 210 is greater than or equal to a preset value, verified through multiple tests, such as 90°, to prevent adhesion between the cover plate 110 and the grating 140 or the waveguide substrate 130, thereby reducing the Newton ring phenomenon that may occur during wiping. The cover plate is made of glass or a resin such as PE.

[0034] It is explained here that the figure only shows the case where a flexible transparent member is provided on the second surface. The present invention also includes providing a flexible transparent member of a certain thickness on the grating structure. There is no limitation on the position of the surface where the flexible transparent member is located. It can be on the second surface of the cover plate or on the grating structure, as long as it can be ensured that there is a flexible transparent member between the two. The present invention does not impose any position limitation on this.

[0035] It is further explained here that the flexible transparent member 210 of a certain thickness is provided on the second surface of the cover plate as described in the present invention, which refers to depositing the flexible transparent member material on the flexible substrate and adhering the flexible substrate to the second surface, or depositing the flexible transparent member material on the surface by depositing the corresponding material, or when the flexible transparent member is provided on the grating structure, the method of depositing the material is not limited as long as the contact angle is greater than or equal to the preset value.

[0036] Furthermore, a black waterproof and breathable adhesive is applied to the side edges of at least one cover plate 110 and / or at least one waveguide substrate 130; the transmittance of the black waterproof and breathable adhesive is ≤0.1%. The black waterproof and breathable adhesive is applied to the side edges to absorb edge stray light, thereby reducing the impact of stray light and improving display efficiency. Furthermore, in the first embodiment, the thickness of the flexible transparent member 210 is specified to be uniform, such as 20 nm, 10 nm, 1 nm, etc., and the thickness can be adjusted according to actual conditions, and the flexible transparent member 210 completely covers the grating structure. Of course, for those skilled in the art, in order to reduce or eliminate the Newton ring phenomenon, the thickness of the flexible transparent member 210 can be specified to be non-uniform based on actual test results, such as different thicknesses on the left and right sides, or the thickness can be adjusted, or the thickness can be partially covered by the grating structure, or a combination thereof. This is also an embodiment of the present invention and is also protected by the present invention, and is not limited here.

[0037] Furthermore, in order to prevent adhesion between the cover plate 110 and the grating 140 or the waveguide substrate 130, the present invention has been verified through multiple tests, and flexible transparent parts of different materials are selected and their contact angles are tested. According to the test results and based on different requirements, flexible transparent parts with different contact angles are selected, and the contact angles of different flexible transparent parts are set. According to the recovery situation between the cover plate and the waveguide and the situation of the Newton ring phenomenon, through a large number of experimental tests, it is concluded that when the contact angle of the flexible transparent part 210 is greater than or equal to 90°, the recovery effect between the cover plate 110 and the waveguide substrate 130 is better. The flexible transparent part with this angle can prevent adhesion between the cover plate and the substrate and restore it to the original gap state. The gap is consistent before and after, which helps to reduce the Newton ring phenomenon.

[0038] For those skilled in the art, the flexible transparent member can be defined as an ultra-micro nanostructure layer; or the flexible transparent member can be composed of a material having two functional groups, namely, a low surface energy fluorinated group and a surface reactive group; through the action of the functional groups, when the organic fluoride contacts the material surface of the cover plate, the surface reactive group will chemically react with the corresponding surface functional group, generating chemical bonds on the surface of the cover plate, and then forming a flexible transparent member with a certain thickness.

[0039] Furthermore, those skilled in the art will appreciate that the flexible transparent member 210 is deposited on the second surface or grating structure via magnetron sputtering or evaporation. For example, vacuum evaporation involves heating and evaporating the material under vacuum conditions, causing the particles to condense and form on the substrate surface. Alternatively, spraying or dipping can be used to evenly apply the material directly to one surface of the cover plate using high pressure. Alternatively, the flexible transparent member material can be deposited on a flexible substrate, which is then attached to the first and / or second surfaces. The flexible substrate can be made from commonly used materials in the art that have electrochromic or explosion-proof properties.

[0040] As in Example 2, Figure 3 As shown, the diffraction light waveguide lens structure is as described in Example 1. According to actual requirements, a layer of flexible transparent member 210 can be provided on both the first surface and the second surface of the substrate 110 to ensure the anti-adhesion property of the substrate surface and improve the usability of the lens.

[0041] As in Example 3, Figure 4 As shown, the diffraction light waveguide lens structure is as described in Example 1. Furthermore, the diffraction light waveguide lens structure is as described above. In order to enhance the transmittance of light, a layer of AR film 310 can be preferentially provided on the first surface and / or the second surface of the substrate 110, and then a layer of flexible transparent member 210 is respectively provided on the AR film 310 on both sides to minimize the influence on the transmittance of the waveguide itself and reduce the Newton ring phenomenon.

[0042] Furthermore, the principle of the present invention is further explained. A suitable flexible transparent material is selected within a certain angle range and is disposed on the second surface of the cover. The present invention has been tested many times, and the test data are shown in the following table (only examples, not exhaustive):

[0043]

[0044]

[0045] In order to solve the adhesion problem between the cover and the grating or waveguide substrate, flexible transparent parts with different performance materials were prepared and their contact angles were tested. Figure 5 It can be seen that based on whether the water droplets automatically slide down when the cover surface is tilted, and based on the requirements of vision and cleanliness, as shown in the attached Figure 5 (C) As described above, when the contact angle of the flexible transparent member is greater than or equal to 90°, the hydrophobicity is better, which can better prevent adhesion and achieve the purpose of being beautiful and easy to clean. Therefore, when this contact angle is met, when the flexible transparent member on the cover plate contacts other surfaces, the adhesion force with other surfaces can be reduced, and the two are not easily adhered. When the cover plate is subjected to force, the flexible transparent member on the second surface of the cover plate contacts the optical waveguide, which can prevent adhesion or connection between the cover plate and the waveguide. Then, through the self-restoring force of the cover plate or substrate, the gap between the cover plate and the waveguide can be quickly restored to maintain the original state, thereby ensuring the imaging effect, preventing the imaging quality of the optical waveguide lens from deteriorating during repeated use, ensuring that the user can always maintain the original performance of the optical waveguide when wiping surface stains or wearing it, improving the imaging quality of the optical waveguide, and having unexpected technical effects. By depositing materials on the surface of the cover plate or directly pasting the formed flexible transparent member and / or depositing materials on the grating structure, the strength of the lens can be improved, explosion-proof, and prevented from breaking to improve the safety of use. The method of deposition or direct pasting can be selected based on process costs (such as cost, whether the deposition is easy to repair, warping, etc.), and the present invention does not limit this. It should be noted that the present invention is attached Figure 1-4 The examples do not limit the number of cover plates or waveguides. In one embodiment, the diffractive waveguide lens includes two cover plates and a waveguide substrate, with the two cover plates stacked on either side of the waveguide substrate. In another embodiment, the diffractive waveguide lens includes one cover plate and multiple waveguide substrates, with the cover plate and multiple waveguide substrates stacked in sequence. In another embodiment, the diffractive waveguide lens includes two cover plates and multiple waveguide substrates, with the waveguide substrate stacked between the two cover plates. The cover plate prevents dirt and oil stains on the waveguide substrates, which could affect the total internal reflection optical path of the image and, in turn, image quality. For any cover plate, when there is a grating structure on the surface of the waveguide substrate facing the cover plate, a flexible transparent member is provided on the side of the cover plate facing the waveguide substrate to prevent adhesion. The position of the flexible transparent member is not limited and may be on the first surface and / or the second surface of the cover plate. When multiple waveguide plates are stacked adjacent to each other, for any waveguide plate, when there is a grating structure on the surface of other waveguide plates facing it, a flexible transparent member is provided on the side of the waveguide plate facing the waveguide plate to prevent adhesion.

[0046] The present invention also provides a method for preparing a diffractive optical waveguide lens 100. First, at least one waveguide substrate 130 is provided. A grating structure 140 is provided on at least one side of the waveguide substrate 130. In some embodiments, the grating structure 140 is provided on both sides of the waveguide substrate 130.

[0047] At least one cover plate 110 is provided, the cover plate having a first surface and a second surface opposite to the first surface, and a flexible transparent member 210 of a certain thickness is respectively provided on at least one of the first surface, the second surface, and the grating structure of the cover plate 110, and the flexible transparent member at least partially covers the grating structure; in some embodiments, the flexible transparent member 210 may be provided on both the first surface and the second surface of the cover plate; further, the flexible transparent member 210 may be provided on both the first surface and the second surface of the cover plate and the grating structure; the contact angle of the flexible transparent member is greater than or equal to a preset value to prevent the cover plate from contacting the grating or waveguide substrate. Adhesion is generated; or further, before the flexible transparent member 210 is formed, a layer of AR film is preferentially deposited on the second surface; or further, before the flexible transparent member 210 is formed, a layer of AR film is preferentially deposited on the first surface and / or the second surface; further, when the flexible transparent member is provided on the first surface and / or the second surface of the cover plate, the side of the cover plate having the flexible transparent member is directed toward the grating structure to be formed on the grating structure, thereby obtaining the diffraction light waveguide lens; and / or; when the flexible transparent member is provided on the grating structure, either side of the cover plate is directed toward the grating structure to be formed on the grating structure, thereby obtaining the diffraction light waveguide lens.

[0048] The flexible transparent member 210 on the cover plate 110 or the grating structure 140 can reduce the adhesion to other surfaces when in contact with other surfaces, and can prevent the cover plate and the waveguide from being adhered or connected when force is applied to the flexible transparent member. As a result, the relative state between the cover plate and the waveguide substrate can be restored to the original gap state after the external force disappears, thereby realizing the reuse of the diffraction light waveguide lens, improving the imaging effect, achieving a better display effect, and ensuring the imaging quality before and after use, which has unexpected technical effects.

[0049] The above embodiments only show that different flexible transparent parts 210 or AR films 310 are set on the first surface and / or second surface of the cover according to different technical standards. Of course, those skilled in the art can make random adjustments based on the core inventive concept of the present invention and still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A diffraction light waveguide lens, characterized in that: include: At least one cover plate and at least one waveguide substrate stacked together; A grating structure is provided on at least one side of the waveguide substrate; the cover plate has a first surface away from the grating structure and a second surface close to the grating structure and opposite to the first surface; a flexible transparent member of a certain thickness is provided on the second surface and / or the grating structure, and the surface of the flexible transparent member is flattened; the flexible transparent member at least partially covers the grating structure; the contact angle of the flexible transparent member is greater than or equal to 90° to prevent adhesion between the cover plate and the grating or waveguide substrate; the flexible transparent member is composed of a material having two functional groups: low surface energy fluorinated groups and surface reactive groups; through the action of the functional groups, when the organic fluoride contacts the second surface and / or the material surface of the grating structure, the surface reactive groups will chemically react with the corresponding surface functional groups, thereby generating chemical bonds on the second surface and / or the surface of the grating structure.

2. The diffraction light waveguide lens according to claim 1, characterized in that: The thickness of the flexible transparent member is uniform, and partially or completely covers the grating structure; or the thickness of the flexible transparent member is non-uniform, and partially or completely covers the grating structure.

3. The diffraction light waveguide lens according to any one of claims 1 to 2, characterized in that: The flexible transparent member is also provided on the first surface, and the thickness of the flexible transparent member on the first surface and the flexible transparent member on the second surface are the same or different.

4. The diffraction light waveguide lens according to any one of claims 1 to 2, characterized in that: Before forming the flexible transparent member, a layer of AR film is preferentially deposited on the first surface and / or the second surface.

5. The diffraction light waveguide lens according to claim 4, characterized in that: Before arranging the flexible transparent member on the first surface and the second surface, a layer of AR film is preferentially deposited on the first surface and the second surface respectively.

6. The diffraction light waveguide lens according to any one of claims 1 or 5, characterized in that: A black waterproof and breathable adhesive material is coated on the side edges of the at least one cover plate and / or the at least one waveguide substrate.

7. An augmented reality display device, characterized in that: The waveguide of the display device is the diffraction light waveguide lens according to any one of claims 1 to 6.

8. A method for preparing a diffractive light waveguide lens, applied to the diffractive light waveguide lens according to any one of claims 1 to 6, characterized in that: Providing at least one waveguide substrate, wherein a grating structure is provided on at least one side of the waveguide substrate; Providing at least one cover plate, the cover plate having a first surface away from the grating structure and a second surface close to the grating structure and opposite to the first surface; A flexible transparent member of a certain thickness is respectively provided on the first surface, the second surface and at least one of the grating structure of the cover plate, wherein the flexible transparent member at least partially covers the grating structure, and a contact angle of the flexible transparent member is greater than or equal to a preset value to prevent adhesion between the cover plate and the grating or waveguide substrate; Furthermore, when a flexible transparent member is provided on the first surface and / or the second surface of the cover plate, the side of the cover plate having the flexible transparent member is oriented toward the grating structure and formed on the grating structure to obtain the diffraction light waveguide lens; And / or; when a flexible transparent member is provided on the grating structure, either side of the cover plate is directed toward the grating structure and formed on the grating structure to obtain the diffraction light waveguide lens.

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