Diffraction optical waveguide and near-eye display device

Abstract

The embodiment of the utility model discloses a diffraction optical waveguide and near-eye display equipment, the diffraction optical waveguide comprises at least one layer of waveguide sheet, the waveguide sheet comprises a first surface and a second surface which are parallel to each other along the thickness direction of the waveguide sheet, and the first surface and / or the second surface at least comprises a coupling-in grating and a coupling-out grating; the coupling-in grating is used for coupling image light rays emitted by an optical machine into the waveguide sheet, so that the image light rays are totally reflected to the coupling-out grating in the waveguide sheet and are coupled out of the waveguide sheet through the coupling-out grating; an optical resin material layer is at least arranged in the area where the coupling-out grating is located, the optical resin material layer completely fills a grating groove of the coupling-out grating, and a flat and smooth surface is formed on the side, away from the waveguide sheet, of the optical resin material layer. The diffraction optical waveguide provided by the utility model is light in weight, thin in thickness and good in safety performance.

Description

Technical Field

[0001] The present application relates to the field of augmented reality, and particularly to a diffractive optical waveguide and a near-eye display device. Background Art

[0002] A diffractive optical waveguide generally includes at least one waveguide layer and at least one protective layer. The protective layer is used to protect the grating structure in the waveguide layer to prevent the grating structure from being damaged. Usually, the waveguide layers or between the waveguide layer and the protective layer are edge-bonded using double-sided tape or photo-curing / thermal-curing glue. However, there are air gaps between the waveguide layers or between the waveguide layer and the protective layer, resulting in poor drop resistance and potential safety hazards. Utility Model Content

[0003] To solve the problems existing in the prior art, the present utility model proposes a new diffractive optical waveguide structure. By providing an optical resin material layer at least in the area where the output grating is located, the optical resin material layer is used to protect the grating, eliminating the need for an additional protective layer. Moreover, while achieving lightweight, the overall strength of the waveguide can be ensured, improving the safety of the diffractive optical waveguide, with unexpected technical effects.

[0004] Based on this, the present application provides a diffractive optical waveguide, comprising:

[0005] At least one waveguide layer, having a first surface and a second surface parallel to each other along the thickness direction of the waveguide layer. At least an input grating and an output grating are included on the first surface and / or the second surface. The input grating is used to couple the image light emitted by the light engine into the waveguide layer, so that the image light is totally reflected in the waveguide layer to the output grating and is coupled out of the waveguide layer by the output grating. At least in the area where the output grating is located, there is an optical resin material layer, which completely fills the grating grooves of the output grating and forms a flat and smooth surface on the side away from the waveguide layer.

[0006] Implementably, the input grating and / or the output grating is a multi-layer structure.

[0007] Implementably, the thickness of the waveguide layer is 0.3 - 1 mm, and the thickness of the optical resin material layer is 3 - 30 μm.

[0008] Implementably, the optical resin material layer at least covers the effective optical path area. The effective optical path area includes the areas where the input grating and the output grating are located, and the area through which the image light travels from the input grating to the output grating.

[0009] Implementably, the diffractive optical waveguide further includes a functional film layer, which is disposed on the surface of the optical resin material layer.

[0010] Implementably, the functional film layer includes at least one of an antireflection film, a waterproof film, a radiation-resistant film, an explosion-proof film, and an antifogging film.

[0011] Implementably, the diffractive optical waveguide includes at least two waveguide sheets which are stacked and connected, and the regions where the grating structures are located between the waveguide sheets are connected by the optical resin material layer.

[0012] Implementably, the diffractive optical waveguide further includes a turning grating, and the optical resin material layer completely fills the grating grooves of the turning grating.

[0013] On the other hand, the present application also provides a near-eye display device, which includes: a device body and the diffractive optical waveguide as described in any one of the foregoing items provided on the device body.

[0014] Implementably, the device body includes temple arms and a frame, and an optical engine is disposed inside the temple arms.

[0015] For the diffractive optical waveguide and the near-eye display device provided by the present application, by providing an optical resin material layer at least in the region where the output grating is located, the grating is protected by the optical resin material layer, and there is no need to additionally increase a protective sheet. Moreover, while achieving lightweight, the overall strength of the waveguide can be ensured, and the safety of the diffractive optical waveguide is improved, having an unexpected technical effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0017] Figure 1 It is a schematic structural diagram of a diffractive optical waveguide in an embodiment of the present application;

[0018] Figure 2 It is a schematic structural diagram of a diffractive optical waveguide in another embodiment of the present application;

[0019] Figure 3 It is a schematic structural diagram of a diffractive optical waveguide in another embodiment of the present application;

[0020] Figure 4 It is a schematic structural diagram of a diffractive optical waveguide in another embodiment of the present application;

[0021] Figure 5 It is a schematic structural diagram of a diffractive optical waveguide in another embodiment of the present application;

[0022] Figure 6 Schematic structural diagram of a diffractive optical waveguide in another embodiment of the present application;

[0023] Reference signs:

[0024] 110: Waveguide sheet;

[0025] 111: First surface;

[0026] 112: Second surface;

[0027] 120: Input grating;

[0028] 130: Output grating;

[0029] 140: Optical resin material layer;

[0030] 150: Turning grating;

[0031] 160: Functional film layer. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0033] Next, the technical solutions of the present application will be described in detail with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0034] According to one aspect of the present invention, a diffractive optical waveguide is provided, including: at least one layer of waveguide sheet, which includes a first surface and a second surface parallel to each other along the thickness direction of the waveguide sheet, and at least an input grating and an output grating are included on the first surface and / or the second surface; the input grating is used to couple the image light rays emitted by the optical machine into the waveguide sheet, so that the image light rays are totally reflected in the waveguide sheet to the output grating and are coupled out of the waveguide sheet through the output grating; at least an optical resin material layer is provided in the area where the output grating is located, the optical resin material layer completely fills the grating grooves of the output grating, and a flat and smooth surface is formed on the side away from the waveguide sheet.

[0035] Reference Figure 1, the diffractive optical waveguide includes a waveguide sheet 110, which includes a first surface 111 and a second surface 112 that are parallel to each other along the thickness direction of the waveguide sheet 110. An input grating 120 and an output grating 130 are included on the first surface 111; the input grating 120 is used to couple the image light rays emitted from the optical machine into the waveguide sheet 110, so that the image light rays are totally reflected in the waveguide sheet 110 to the output grating 130 and are coupled out of the waveguide sheet 110 through the output grating 130; at least in the area where the output grating 130 is located, an optical resin material layer 140 is provided. The optical resin material layer 140 completely fills the grating grooves of the output grating 130, and a flat and smooth surface is formed on the side away from the waveguide sheet 110.

[0036] Among them, the thickness of the waveguide sheet is 0.3 - 1 mm, and the thickness of the optical resin material layer is 3 - 30 μm. The refractive index of the optical resin material layer is 1.1 - 1.6, the refractive index of the waveguide sheet is greater than 1.7, and the difference in refractive index between the optical resin material layer and the waveguide sheet is at least greater than 0.6.

[0037] In some embodiments, the input grating 120 and the output grating 130 can also be provided on the second surface 112; or, the input grating 120 and the output grating 130 are both provided on the first surface 111 and the second surface 112; or, the input grating 120 and the output grating 130 are respectively provided on the first surface 111 and the second surface 112.

[0038] Implementably, the input grating and / or the output grating of the diffractive optical waveguide provided in this application is a multi-layer structure. Specifically, refer to Figure 2 , the diffractive optical waveguide includes a waveguide sheet 110, and an input grating 120 and an output grating 130 are included on one of the surfaces of the waveguide sheet 110; among them, the output grating 130 includes two layers of grating structures, and the grating materials, duty ratios, grating depths, and grating tooth shapes of the first layer of grating structure and the second layer of grating structure can be the same or different; the optical resin material layer 140 also includes two layers, and the materials and thicknesses of the first layer of optical resin material layer and the second layer of optical resin material layer can be the same or different.

[0039] In this embodiment, the grating structure is designed as a multi-layer structure, which greatly improves the design freedom. Among them, different tilt angles or shapes can improve the efficiency of a specific field of view angle of a certain color beam to meet the design functions of each grating functional area (such as the input area, expansion area, output area, etc.) of the diffractive optical waveguide, which is beneficial to realizing single-chip full-color display.

[0040] Implementably, the optical resin material layer at least covers the effective optical path area; the effective optical path area includes the areas where the input grating and the output grating are located, and the area through which the image light rays pass from the input grating to the output grating.

[0041] It can be understood that for a waveguide sheet, the grating structure within the grating structure region thereof couples light rays (such as the image light rays emitted by an optical engine) into the waveguide sheet. The image light rays are transmitted within the waveguide sheet to the front region of the human eye and then coupled out of the waveguide sheet through the grating structure and into the human eye. When the waveguide sheet includes an input grating and an output grating, the image light rays enter the waveguide sheet from the input grating, are totally reflected and transmitted in the waveguide sheet to the output grating, and are coupled out of the waveguide sheet by the output grating. The effective optical path region is the region where the path passes through during the process from the image light rays entering the waveguide sheet to exiting the waveguide sheet, including the regions where the input grating and the output grating are located, and the region through which the image light rays pass from the input grating to the output grating.

[0042] Implementably, the diffractive optical waveguide further includes a turning grating, and the grating grooves of the turning grating are completely filled with an optical resin material layer.

[0043] Further, when the diffractive optical waveguide includes a turning grating, the image light rays enter the waveguide sheet from the input grating, are totally reflected and transmitted in the waveguide sheet to the turning grating, then are diffracted and deflected by the turning grating towards the output grating, and are coupled out of the waveguide sheet by the output grating. The effective optical path region is the region where the path passes through during the process from the image light rays entering the waveguide sheet to exiting the waveguide sheet, including the regions where the input grating, the turning grating, and the output grating are located, and the region through which the image light rays pass from the input grating to the turning grating and then to the output grating.

[0044] Specifically, referring to Figure 3 , the diffractive optical waveguide includes a waveguide sheet 110, and an input grating 120, a turning grating 150, and an output grating 130 are included on one surface of the waveguide sheet 110; the input grating 120 is used to couple the image light rays emitted by the optical engine into the waveguide sheet 110, so that the image light rays are totally reflected in the waveguide sheet 110 to the turning grating 150, then are deflected by the turning grating 150 towards the output grating 130, and are coupled out of the waveguide sheet 10 by the output grating 130; an optical resin material layer 140 is provided in the effective optical path region, and the grating grooves of the input grating 120, the turning grating 150, and the output grating 130 are completely filled with the optical resin material layer 140, and a flat and smooth surface is formed on the side away from the waveguide sheet 110.

[0045] Implementably, the diffractive optical waveguide further includes a functional film layer, and the functional film layer is disposed on the surface of the optical resin material layer.

[0046] Implementably, the functional film layer includes at least one of an antireflection film, a waterproof film, a radiation-resistant film, an explosion-proof film, and an antifogging film.

[0047] Among them, the antireflection film is an optical film that can reduce or eliminate stray light in the system, also known as an antireflection coating, including but not limited to magnesium fluoride, silicon oxide, aluminum oxide, silicon nitride, titanium oxide, tantalum oxide, zinc sulfide; the waterproof film refers to an outer film with anti-oil and anti-water properties, which is thin and does not change the optical properties of the antireflection film, including but not limited to silicone, polyester, cellulose acetate coating, zirconium oxide coating, fluoride, etc.; the anti-radiation film refers to a film that makes the lens have the function of anti-electromagnetic radiation according to the principle of electromagnetic interference shielding, using a special coating process and special electrical conductor thin film treatment, including but not limited to metal compounds such as silver oxide; the explosion-proof film refers to a film that reduces the risk of waveguide chip bursting by absorbing and dispersing the impact force when accidentally impacted or dropped, usually composed of multiple layers of materials, including a protective film, a hardening layer, a transparent polyester film, an adhesive layer, and a release film; the anti-fog film refers to a film with anti-fog properties, including but not limited to silicone, polyester, cellulose acetate coating, zirconium oxide coating, fluoride, etc.

[0048] Specifically, referring to Figure 4 , the diffractive optical waveguide includes a waveguide chip 110, and on one surface of the waveguide chip 110, there are an input grating 120, a turning grating 150, and an output grating 130; the input grating 120 is used to couple the image light rays emitted by the optical machine into the waveguide chip 110, so that the image light rays are totally reflected in the waveguide chip 110 to the turning grating 150, then deflected by the turning grating 150 to the output grating 130, and coupled out of the waveguide chip 110 through the output grating 130; an optical resin material layer 140 is provided in the effective optical path region, and the optical resin material layer 140 completely fills the grating grooves of the input grating 120, the turning grating 150, and the output grating 130, and forms a flat and smooth surface on the side away from the waveguide chip 110. A functional film layer 160 is provided on the surface of the optical resin material layer 140 and on the surface of the waveguide chip outside the optical resin material layer 140.

[0049] In another embodiment, an optical resin material layer is also provided on the other surface of the waveguide chip where no grating structure is provided, for protecting the waveguide chip. Specifically, referring to Figure 5 , the diffractive optical waveguide includes a waveguide chip 110, and on the first surface 111 of the waveguide chip 110, there are an input grating 120, a turning grating 150, and an output grating 130; an optical resin material layer 140 is provided in the effective optical path region, and the optical resin material layer 140 completely fills the grating grooves of the grating structure, and forms a flat and smooth surface on the side away from the waveguide chip 110. A functional film layer 160 is provided on the surface of the optical resin material layer 140 and on the first surface 111 outside the optical resin material layer 140. An optical resin material layer 140 is also provided on the second surface 112 of the waveguide chip 110.

[0050] In the diffractive optical waveguide provided by the present application, by providing an optical resin material layer at least in the region where the output grating is located, the optical resin material layer is used to protect the grating, eliminating the need for an additional protective sheet. Moreover, the optical resin material layer is a flexible material with a certain buffering effect. Additionally, it can achieve lightweight while ensuring the overall strength of the waveguide, improving the safety of the diffractive optical waveguide, and having unexpected technical effects.

[0051] Furthermore, in some embodiments, the diffractive optical waveguide achieves full-color display by stacking multiple waveguide sheets. Practically, the diffractive optical waveguide includes at least two waveguide sheets stacked and connected, and the regions where the grating structures are located between the waveguide sheets are connected by an optical resin material layer.

[0052] Specifically, referring to Figure 6 , the diffractive optical waveguide includes two waveguide sheets 110 stacked and connected, and the regions where the grating structures (such as the output grating 130) are located between the waveguide sheets 110 are connected by an optical resin material layer 140. The optical resin material layer 140 can play a supporting role between the waveguide sheets, reducing the air gap between the waveguide sheets and enhancing the anti-drop performance.

[0053] According to another aspect of the present invention, embodiments of the present invention provide a near-eye display device, which includes: a device body and the diffractive optical waveguide provided in any of the foregoing embodiments disposed on the device body.

[0054] Practically, the device body includes temple arms and a frame. The light engine is disposed inside the temple arms, and the display lens is disposed on the frame.

[0055] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; 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 diffractive optical waveguide, characterized in that Comprising: At least one waveguide sheet, which includes a first surface and a second surface parallel to each other along the thickness direction of the waveguide sheet, and at least an input grating and an output grating are included on the first surface and / or the second surface; the input grating is used to couple the image light rays emitted by the optical engine into the waveguide sheet, so that the image light rays are totally reflected in the waveguide sheet to the output grating and are coupled out of the waveguide sheet through the output grating; at least in the area where the output grating is located, an optical resin material layer is provided, the optical resin material layer completely fills the grating grooves of the output grating, and a flat and smooth surface is formed on the side away from the waveguide sheet.

2. The diffractive optical waveguide according to claim 1, wherein The input grating and / or the output grating is a multi-layer structure.

3. The diffractive optical waveguide according to claim 1, characterized in that, The thickness of the waveguide sheet is 0.3 - 1 mm, and the thickness of the optical resin material layer is 3 - 30 μm.

4. The diffractive optical waveguide according to claim 1, wherein The optical resin material layer at least covers the effective optical path area; the effective optical path area includes the areas where the input grating and the output grating are located, and the area through which the image light rays pass from the input grating to the output grating.

5. The diffractive optical waveguide according to claim 4, characterized in that, The diffractive optical waveguide further includes a functional film layer, and the functional film layer is provided on the surface of the optical resin material layer.

6. The diffractive optical waveguide according to claim 5, wherein The functional film layer includes at least one of an antireflection film, a waterproof film, a radiation-resistant film, an explosion-proof film, and an antifogging film.

7. The diffractive optical waveguide according to claim 1, wherein The diffractive optical waveguide includes at least two waveguide sheets, the two waveguide sheets are stacked and connected, and the area where the grating structure is located between the waveguide sheets is connected through the optical resin material layer.

8. The diffractive optical waveguide according to claim 1, wherein The diffractive optical waveguide further includes a turning grating, and the optical resin material layer completely fills the grating grooves of the turning grating.

9. A near-eye display device, characterized in that, The near-eye display device includes: a device body and a diffractive optical waveguide as described in any one of claims 1 - 8 provided on the device body.

10. The near-eye display device according to claim 9, wherein The device body includes temple arms and a frame, and the optical engine is provided inside the temple arms.

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