WO2025025611A1 - Diffraction optical waveguide and augmented reality device - Google Patents

Abstract

A diffraction optical waveguide and an augmented reality device comprising same. The diffraction optical waveguide comprises a waveguide layer (10), a protective layer (20) and a support structure (30); the waveguide layer (10) and the protective layer (20) are spaced apart from each other; the support structure (30) is arranged between the waveguide layer (10) and the protective layer (20); and when at least one of the waveguide layer (10) and the protective layer (20) deforms and when the waveguide layer (10) is relatively close to the protective layer (20), the support structure (30) is used for keeping the distance between the waveguide layer (10) and the protective layer (20) not less than a predetermined value. The distance between the waveguide layer (10) and the protective layer (20) is kept by means of the support structure (30) to prevent the protective layer (20) from being too close to the waveguide layer (10), thereby avoiding the occurrence of interference.

Description

Diffractive optical waveguides and augmented reality devices Technical Field

The present application belongs to the field of augmented reality technology, and specifically, relates to a diffraction optical waveguide and an augmented reality device.

Background Art

The optical module of an augmented reality (AR) near-eye display device usually consists of two parts: an optical machine (or light engine) and an optical combiner. The optical machine consists of an image source and a projection lens. The image source is used to generate the image to be displayed, and the projection lens projects the image displayed by the image source to infinity or a specified distance. The optical combiner can transmit the signal light emitted by the optical machine to the human eye in a directionally manner, forming the image to be displayed on the retina; at the same time, the optical combiner has good transmittance to the ambient light in the real world. Through the optical combiner, the human eye can see the real-world scenery and the image projected by the optical machine at the same time; the diffraction optical waveguide is the preferred solution for the optical combiner because of its thin thickness, light weight and good light transmittance.

As shown in FIG1 , the diffraction optical waveguide is usually composed of a plurality of diffraction waveguide layers 4, at least one protective layer 3, and adhesive 2 for bonding the diffraction waveguide layers 4 and the protective layer 3. A coupling-in grating and a coupling-out grating are arranged on the surface of each diffraction waveguide layer. The coupling-in grating is used to couple the light emitted by the light engine 1 into the diffraction waveguide layer and cause total reflection. After total reflection in the diffraction waveguide layer, the light is transmitted to the coupling-out grating. The coupling-out grating diffracts the light in the diffraction waveguide layer into the free space. After entering the human eye, a virtual image to be displayed is formed on the retina. In addition to the coupling-in grating and the coupling-out grating, a turning grating may also be arranged on the surface of each diffraction waveguide layer to achieve requirements such as pupil expansion.

In order to prevent the grating structure on the waveguide layer from being damaged, a protective layer is usually provided to protect the grating structure. As shown in FIG1 , the protective layer and the diffraction waveguide layer are spaced apart and the two are fixed by adhesive 2, and the gap between the protective layer and the waveguide layer is filled with air. When squeezed by external force, as shown in FIG2 , the protective layer 3 and the diffraction waveguide layer 4 are deformed and approach or even fit each other. At this time, interference is likely to occur at the place where the protective layer 3 and the diffraction waveguide layer 4 are close or fit, affecting the user's visual experience.

Summary of the invention

The technical problem solved by the present application is: how to prevent the layers of the diffraction optical waveguide from generating interference effects due to deformation of the material under stress, so as to avoid affecting the visual experience.

The present application provides a diffractive optical waveguide, which includes a waveguide layer, a protective layer and a supporting structure, wherein the waveguide layer and the protective layer are spaced apart, and the supporting structure is disposed between the waveguide layer and the protective layer, and when at least one of the waveguide layer and the protective layer is deformed and the waveguide layer and the protective layer are relatively close, the supporting structure is used to maintain the spacing between the waveguide layer and the protective layer to be not less than a predetermined value.

Optionally, the supporting structure is disposed on the waveguide layer or the protective layer.

Optionally, the support structure is disposed on an inner surface of the protective layer facing the waveguide layer, and when at least one of the waveguide layer and the protective layer is deformed and the waveguide layer is relatively close to the protective layer, the support structure is used to abut against the waveguide layer.

Optionally, the supporting structure comprises a plurality of protrusions distributed at intervals.

Optionally, the thickness of the protrusion is greater than or equal to the predetermined value and less than or equal to the initial spacing value, and the initial spacing value is the spacing value between the waveguide layer and the protective layer when neither the waveguide layer nor the protective layer is deformed.

Optionally, a portion of the plurality of protrusions are located in a central area of the protective layer, another portion of the plurality of protrusions are located in an edge area of the protective layer, and a thickness of the protrusions located in the central area is less than a thickness of the protrusions located in the edge area.

Optionally, the predetermined value is a minimum distance for avoiding interference between the waveguide layer and the protective layer.

Optionally, the support structure is made of resin or glass.

Optionally, a projection of the support structure on the waveguide layer is offset from a grating region of the waveguide layer.

The present application also provides an augmented reality device, which includes the above-mentioned diffraction optical waveguide.

The present application provides a diffractive optical waveguide and an augmented reality device, which have the following technical effects:

The diffraction optical waveguide provided in the present application has a support structure arranged between the waveguide layer and the protective layer. When the waveguide layer and the protective layer are close to or even in contact with each other due to deformation, the support structure is used to maintain the distance between the waveguide layer and the protective layer to prevent the protective layer and the waveguide layer from being too close to each other, thereby avoiding interference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of an assembly of an optical engine and a diffractive optical waveguide in the prior art;

FIG2 is a schematic diagram of the diffraction optical waveguide in FIG1 when being squeezed by an external force;

FIG3 is a schematic diagram of an optical engine and a diffractive optical waveguide assembly according to one or more embodiments;

FIG4 is a schematic diagram of the diffraction optical waveguide in FIG3 when being squeezed by an external force;

FIG5 is a top view of a diffractive optical waveguide according to one or more embodiments;

FIG6 is another schematic diagram of an optical engine and a diffractive optical waveguide assembly according to one or more embodiments;

FIG. 7 is another schematic diagram of assembling a light engine and a diffractive light waveguide according to one or more embodiments;

FIG. 8 is a schematic diagram of a diffractive optical waveguide having a multi-layer structure and an optical engine assembled according to one or more embodiments.

The corresponding relationship between the reference numerals and the component names is as follows:
10- waveguide layer, 20- protective layer, 30- supporting structure, 31- protrusion, 40- adhesive layer.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

Before describing the various embodiments of the present application in detail, the technical concept of the present application is briefly described first: the augmented reality devices of the prior art can be applied to various scenarios. At the same time, the augmented reality devices will also be squeezed by external forces. For example, the diffraction optical waveguide is squeezed and deformed, causing the waveguide layer and the protective layer to be too close or even contact each other, causing interference between the waveguide layer and the protective layer, thereby affecting the viewing effect of the user. To this end, the diffraction optical waveguide provided by the present application is provided with a support structure between the waveguide layer and the protective layer. When the waveguide layer and the protective layer are close to each other due to deformation, the distance between the waveguide layer and the protective layer is maintained by the support structure to prevent the protective layer and the waveguide layer from being too close to each other to avoid interference. The specific structure of the diffraction optical waveguide of the present application is described below in combination with more embodiments.

Specifically, as shown in FIGS. 3 and 4 , the diffractive optical waveguide of the first embodiment includes a waveguide layer 10, a protective layer 20 and a support structure 30. The waveguide layer 10 and the protective layer 20 are spaced apart, and the support structure 30 is disposed between the waveguide layer 10 and the protective layer 20. When at least one of the waveguide layer 10 and the protective layer 20 is deformed and the waveguide layer 10 and the protective layer 20 are relatively close to each other, the support structure 30 is used to maintain the spacing between the waveguide layer 10 and the protective layer 20 to be not less than a predetermined value.

Exemplarily, the diffractive optical waveguide may include multiple waveguide layers 10 and multiple protective layers 20. For example, in one embodiment, the diffractive optical waveguide includes two waveguide layers 10 and two protective layers 20. The two waveguide layers 10 are arranged at intervals, and the two protective layers 20 are arranged as outer protective layers and inner protective layers on the inner side and outer side of the two waveguide layers, respectively. For ease of description, this embodiment 1 is first described by taking the diffractive optical waveguide including a single waveguide layer 10 and a single protective layer 20 as an example.

Specifically, the waveguide layer 10 and the protective layer 20 are fixed by the adhesive layer 40, and the gap between the waveguide layer 10 and the protective layer 20 is sealed by the adhesive layer 40. Exemplarily, the adhesive layer 40 can be an adhesive. In one or more embodiments, the adhesive layer 40 is disposed at the edge of the waveguide layer 10 and the protective layer 20.

Further, the support structure 30 of the first embodiment may be provided on the waveguide layer 10 or the protective layer 20. For example, the support structure 30 may be fixed on the waveguide layer 10, and when the waveguide layer 10 and the protective layer 20 are not deformed, the support structure 30 does not contact the protective layer 20, and after deformation, the support structure 30 abuts against the protective layer 20 to prevent the waveguide layer 10 and the protective layer 20 from further approaching. Similarly, the support structure 30 may be fixed on the protective layer 20, and when the waveguide layer 10 and the protective layer 20 are not deformed, the support structure 30 does not contact the waveguide layer 10, and after deformation, the support structure 30 abuts against the waveguide layer 10 to prevent the waveguide layer 10 and the protective layer 20 from further approaching.

In one embodiment, as shown in FIGS. 3 and 4 , the support structure 30 is disposed on the inner surface of the protective layer 20 facing the waveguide layer 10. When at least one of the waveguide layer 10 and the protective layer 20 is deformed and the waveguide layer 10 and the protective layer 20 are relatively close to each other, the support structure 30 is used to abut against the waveguide layer 10, thereby preventing the waveguide layer 10 and the protective layer 20 from further approaching each other.

In other embodiments, the support structure 30 may be disposed on the adhesive layer 40. For example, one end of the support structure 30 is fixed on the adhesive layer 40, and the other end of the support structure 30 extends into the gap between the waveguide layer 10 and the protective layer 20. When the waveguide layer 10 and/or the protective layer 20 are deformed and the waveguide layer 10 and the protective layer 20 are relatively close to each other, the other end of the support structure 30 abuts against the waveguide layer 10 and the protective layer 20, respectively, so that the waveguide layer 10 and the protective layer 20 maintain a certain distance.

Exemplarily, the support structure 30 includes a plurality of protrusions 31 distributed at intervals.

In one embodiment, as shown in FIG. 5 , a portion of the plurality of protrusions 31 are located in the central region of the protective layer 20 , and another portion of the plurality of protrusions 31 are located in the edge region of the protective layer 20 , so that the plurality of protrusions 31 can be used to achieve uniform support for the waveguide layer 10 .

Further, the thickness T of the protrusion 31 is greater than or equal to the predetermined value d and less than or equal to the initial spacing value D. The initial spacing value D is the spacing value between the waveguide layer 10 and the protective layer 20 when neither the waveguide layer 10 nor the protective layer 20 is deformed, that is, D≥T≥d. In this way, when deformation occurs, the spacing between the waveguide layer 10 and the protective layer 20 can be kept from being too small by the protrusions 31. At the same time, when no deformation occurs, the protrusions 31 will not relatively open the waveguide layer 10 and the protective layer 20, that is, the waveguide layer 10 and the protective layer 20 will not be relatively far away, so as to ensure the normal shape of the waveguide layer 10. The thicknesses of the protrusions 31 may be the same or different. Among them, the predetermined value d is the minimum spacing to avoid interference between the waveguide layer 10 and the protective layer 20. Exemplarily, the range of the thickness T of the protrusion 31 is 5nm to 1mm, the range of the initial spacing value D is 10nm to 100mm, and the predetermined value d is set to 5nm.

In one embodiment, as shown in FIG6 , the thickness of the protrusion 31 located in the center area is less than the thickness of the protrusion 31 located in the edge area. Specifically, the edges of the waveguide layer 10 and the protective layer 20 are fixed by the adhesive layer 40, and the adhesive layer 40 also plays a certain supporting role on the edges of the waveguide layer 10 and the protective layer 20, while the center area of the waveguide layer 10 and the protective layer 20 is not supported. Therefore, when the external pressure makes the waveguide layer 10 and the protective layer 20 relatively close, the deformation degree of the waveguide layer 10 and the protective layer 20 in the center area is greater than that in the edge area. Therefore, by setting the thickness of each protrusion 31, the thickness of the protrusion 31 in the center area is smaller, and the thickness of the protrusion 31 in the edge area is larger, so that each protrusion 31 can evenly support the waveguide layer 10 to avoid damage due to excessive local force. For example, if the thickness of each protrusion 31 is the same, when deformation occurs, the support force of the protrusions 31 in the central area of the waveguide layer 10 is greater than the support force of the protrusions 31 in the edge area, which is likely to damage the local structure of the central area of the waveguide layer 10.

In another embodiment, as shown in FIG. 7 , the thickness of the protrusion 31 located in the central region is greater than the thickness of the protrusion 31 located in the edge region. Thus, when the waveguide layer 10 and the protective layer 20 begin to deform, since the deformation degree of the waveguide layer 10 and the protective layer 20 in the central region is greater than that in the edge region, the central region of the waveguide layer 10 and the protective layer 20 is first supported by the protrusion 31, which can prevent the waveguide layer 10 and the protective layer 20 from getting closer, and is conducive to making the distance between the waveguide layer 10 and the protective layer 20 as close to the initial distance value D as possible.

Exemplarily, the protrusion 31 may be a structure of a bump, a column, a convex point, etc. The shape of the cross section of the protrusion 31 (along the thickness direction) may be circular, elliptical, polygonal, etc., for example, a triangle, a quadrilateral, a trapezoid, etc., and accordingly, the protrusion 31 may be a structure of a cone, a cylinder, a truncated cone, etc.

In one embodiment, the protrusion 31 is a convex block, for example, a pyramid-shaped convex block, the bottom of the protrusion 31 is arranged on the inner surface of the protective layer 20 facing the waveguide layer 10, and the tip of the protrusion 31 faces the waveguide layer 10. When the waveguide layer 10 and/or the protective layer 20 are deformed and the waveguide layer 10 and the protective layer 20 are aligned, When the protrusions 31 are close to each other, the tip of the protrusion 31 abuts against the waveguide layer 10 to achieve a supporting effect. At this time, the protrusion 31 and the waveguide layer 10 are in point contact, which can reduce the influence of the protrusion 31 on the waveguide layer 10.

Exemplarily, the material of the support structure 30 may be resin or glass.

Furthermore, the support structure 30 can be formed on the protective layer 20. For example, it can be formed on the protective layer 20 by a steel screen printing process, a yellow light process, a coating process, a semiconductor process, etc. In other embodiments, the support structure 30 can be integrally formed with the protective layer 20, that is, the support structure 30 is formed while the protective layer 20 is prepared.

Further, the projection of the support structure 30 on the waveguide layer 10 is staggered from the grating region of the waveguide layer 10. In one embodiment, when the support structure 30 is a plurality of protrusions 31 distributed at intervals, the protrusions 31 are arranged in a region of the protective layer 20 other than the region opposite to the grating region of the waveguide layer 10, and when the waveguide layer 10 and/or the protective layer 20 are deformed and the waveguide layer 10 and the protective layer 20 are relatively close, the protrusions 31 abut against the non-grating region of the waveguide layer 10, so as to prevent the protrusions 31 from damaging the grating on the waveguide layer 10. The grating region of the waveguide layer 10 includes an in-coupling grating region, a turning grating region, and an out-coupling grating region.

Further, when the diffractive optical waveguide includes a multi-layer structure, as shown in FIG8 , for example, when the diffractive optical waveguide includes a single waveguide layer 10 and two protective layers 20, the two protective layers 20 are respectively arranged at intervals on both sides of the waveguide layer 10, and a support structure 30 can be arranged on the inner surface of each protective layer 20 facing the waveguide layer 10, so that each protective layer 20 maintains a certain distance from the waveguide layer 10 to avoid interference.

The second embodiment also provides an augmented reality device, which includes the diffraction optical waveguide in the first embodiment. The augmented reality device can be suitable for scenes subjected to external force. The support structure is used to avoid excessive deformation of the diffraction optical waveguide, prevent interference between the waveguide layer and the protective layer, and ensure the visual experience of the augmented reality device.

The augmented reality device may be an augmented reality device, such as augmented reality glasses. In the example of augmented reality glasses, the augmented reality device may be configured to transfer data to and receive data from an external processing device via a signal connection, and the signal connection may be a wired connection, a wireless connection, or a combination thereof. However, in other cases, the augmented reality device may be used as a standalone device, i.e., data processing is performed on the augmented reality device itself. The signal connection may be configured to carry any kind of data, such as image data (e.g., still images and/or full motion video, including 2D and 3D images), audio, multimedia, voice, and/or any other type of data. The external processing device may be, for example, a game console, a personal computer, a tablet computer, a smart phone, or other type of processing device. The signal connection may be, for example, a universal serial bus (USB) connection, a Wi-Fi connection, a Bluetooth or Bluetooth low energy (BLE) connection, an Ethernet connection, a cable connection, a DSL connection, a cellular connection (e.g., 3G, LTE/4G, or 5G), or the like, or a combination thereof. Additionally, the external processing device may communicate with one or more other external processing devices via a network, which may be or include, for example, a local area network (LAN), a wide area network (WAN), an intranet, a metropolitan area network (MAN), the global Internet, or a combination thereof.

It should be noted that it is understandable that a complete augmented reality glasses should also have other necessary basic components, but the other components are not the focus of this embodiment, so they are not shown in the drawings and are not described in detail in the specification, and these components are well-known technologies to those skilled in the art.

The specific implementation methods of the present application are described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that these embodiments can be modified and improved without departing from the principles and spirit of the present application whose scope is defined by the claims and their equivalents. These modifications and improvements should also be within the scope of protection of the present application.

Claims (10)

A diffractive optical waveguide, wherein the diffractive optical waveguide comprises a waveguide layer, a protective layer and a supporting structure, wherein the waveguide layer and the protective layer are spaced apart, and the supporting structure is disposed between the waveguide layer and the protective layer, and when at least one of the waveguide layer and the protective layer is deformed and the waveguide layer and the protective layer are relatively close, the supporting structure is used to maintain the spacing between the waveguide layer and the protective layer to be not less than a predetermined value. The diffractive optical waveguide according to claim 1, wherein the support structure is disposed on the waveguide layer or the protective layer. The diffraction optical waveguide according to claim 2, wherein the support structure is arranged on the inner surface of the protective layer facing the waveguide layer, and when at least one of the waveguide layer and the protective layer is deformed and the waveguide layer is relatively close to the protective layer, the support structure is used to abut the waveguide layer. The diffractive optical waveguide according to claim 2 or 3, wherein the support structure comprises a plurality of protrusions distributed at intervals. The diffractive optical waveguide according to claim 4, wherein the thickness of the protrusion is greater than or equal to the predetermined value and less than or equal to the initial spacing value, and the initial spacing value is the spacing value between the waveguide layer and the protective layer when neither the waveguide layer nor the protective layer is deformed. The diffractive optical waveguide according to claim 4, wherein a portion of the plurality of protrusions are located in a central area of the protective layer, another portion of the plurality of protrusions are located in an edge area of the protective layer, and a thickness of the protrusions located in the central area is less than a thickness of the protrusions located in the edge area. The diffractive optical waveguide according to claim 1, wherein the predetermined value is a minimum distance that avoids interference between the waveguide layer and the protective layer. The diffractive optical waveguide according to claim 1, wherein the support structure is made of resin or glass. The diffractive optical waveguide according to claim 2, wherein a projection of the support structure on the waveguide layer is offset from a grating region of the waveguide layer. An augmented reality device, wherein the augmented reality device comprises the diffractive optical waveguide according to any one of claims 1 to 9.