Flat waveguide display

Abstract

This application relates to tiled waveguide displays. The waveguide display includes a light source, a source waveguide, an output waveguide, and a controller. Light from each light source is coupled into the source waveguide. The source waveguide includes a grating having a constant period determined based on conditions of total internal reflection and first-order diffraction of received image light. The emitted image light is coupled into the output waveguide at several entry positions. The output waveguide outputs the expanded image light at positions offset from the entry positions, and the position / direction of the emitted expanded image light is partially based on the direction of the light source. Each expanded image light is associated with a field of view of the expanded image light emitted by the output waveguide.

Description

[0001] This application is a divisional application of the application with the application date of November 15, 2017, application number 201780071951.X, and invention name "tiled waveguide display". Technical Field

[0002] The present disclosure generally relates to near-eye display systems, and more particularly to tiled waveguide displays. Background Art

[0003] Near-eye light field displays project images directly into a user's eyes, including near-eye displays (NEDs) and electronic viewfinders. Conventional near-eye displays (NEDs) typically have a display element that generates image light that passes through one or more lenses before reaching the user's eyes. Additionally, NEDs in virtual reality systems and / or augmented reality systems typically need to be compact and lightweight, and provide a large exit pupil with a wide field of view for ease of use. However, designing a conventional NED with a wide field of view may result in relatively large lenses, as well as a relatively bulky and heavy NED. Summary of the Invention

[0004] A waveguide display is used to present media to a user. The waveguide display includes a first light source that emits first image light corresponding to a first portion of an image; a second light source that emits second image light corresponding to a second portion of the image, the second portion being different from the first portion of the image; a source waveguide that includes a first entrance region, a second entrance region, a first exit region, and a second exit region; an output waveguide that includes a third entrance region and a third exit region, and a controller that generates and provides scan instructions to the source waveguide.

[0005] The source waveguide couples the first image light within the first entrance region, expands the first image light in at least one dimension, and outputs the expanded first image light via the first exit region. The source waveguide couples the second image light within the second entrance region, expands the second image light in a first dimension, and outputs the expanded second image light via the second exit region. The output waveguide couples the first image light and the second image light within the third entrance region, expands the expanded first image light and the expanded second image light in at least one dimension orthogonal to the first dimension to generate a portion of a magnified image, and outputs the portion of the magnified image to an eye movement range via the third exit region. In some configurations, the expanded first image light propagates in a first direction, and the expanded second image light propagates in a second direction opposite to the first direction.

[0006] In some embodiments, the source waveguide receives first image light in a first region and second image light in a second region, where the first region and the second region are located at the edges of the source waveguide. The first entrance region may include a first coupling element, and the second entrance region may include a second coupling element, and each of the first coupling element and the second coupling element includes a grating element with a grating period selected based on the refractive index of the material forming the source waveguide.

[0007] The present application also provides the following:

[0008] 1) A waveguide display, comprising:

[0009] A first light source configured to emit first image light corresponding to a first portion of an image;

[0010] A second light source configured to emit second image light corresponding to a second portion of the image, the second portion of the image being different from the first portion of the image;

[0011] A source waveguide including a first entrance region, a second entrance region, a first exit region, and a second exit region, the source waveguide being configured to:

[0012] Couple the first image light within the first entrance region, expand the first image light in at least one dimension, and output the expanded first image light via the first exit region, and

[0013] Couple the second image light within the second entrance region, expand the second image light in a first dimension, and output the expanded second image light via the second exit region; and

[0014] An output waveguide including a third entrance region and a third exit region, the output waveguide being configured to couple the first image light and the second image light within the third entrance region, expand the expanded first image light and the expanded second image light in at least one dimension orthogonal to the first dimension to generate a portion of a magnified image, and output the portion of the magnified image to an eye movement range via the third exit region.

[0015] 2) The waveguide display according to 1), wherein the source waveguide receives the first image light in a first region and receives the second image light in a second region, and the first region and the second region are located at opposite edges of the source waveguide.

[0016] 3) The waveguide display according to 1), wherein the first entrance region includes a first coupling element, and the second entrance region includes a second coupling element, and each of the first coupling element and the second coupling element further includes a grating element with a plurality of grating periods, and the grating period is selected based on the refractive index of the material forming the source waveguide.

[0017] 4) The waveguide display according to 1), wherein the source waveguide is associated with a first field of view and a second field of view, and each of the first field of view and the second field of view is a function of the refractive index of the material forming the source waveguide.

[0018] 5) The waveguide display according to 4), wherein each of the first field of view and the second field of view is determined based on the tilt angles of the first image light from the first light source and the second image light from the second light source.

[0019] 6) The waveguide display according to 1), wherein the expanded first image light propagates in a first direction, and the expanded second image light propagates in a second direction opposite to the first direction.

[0020] 7) The waveguide display according to 1), wherein each of the internally coupled first image light and the internally coupled second image light undergoes total internal reflection within the source waveguide.

[0021] 8) The waveguide display according to 1), wherein each of the internally coupled first image light and the internally coupled second image light undergoes first-order diffraction within the source waveguide.

[0022] 9) The waveguide display according to 1), further comprising a first source waveguide and a second source waveguide, wherein the first source waveguide extends along a first dimension, and the second source waveguide extends along a second dimension perpendicular to the first dimension.

[0023] 10) The waveguide display according to 1), wherein the third entrance region includes a first coupling element and a second coupling element, and each of the first coupling element and the second coupling element further includes a grating with a plurality of grating periods, and the grating period is selected based on the refractive index of the material forming the output waveguide.

[0024] 11) A source waveguide, comprising:

[0025] A first entrance region configured to internally couple first image light corresponding to a first portion of an image from a first light source, and the source waveguide expands the first image light in at least one dimension;

[0026] A second input region configured to internally couple second image light corresponding to a second portion of an image from a second light source, the second portion of the image being different from the first portion of the image, the source waveguide expanding the second image light in at least one dimension;

[0027] A first output region configured to output the expanded first image light; and

[0028] A second output region configured to output the expanded second image light.

[0029] 12) The source waveguide according to 11), wherein the source waveguide receives the first image light in a first region and receives the second image light in a second region, the first region and the second region being located at opposite edges of the source waveguide.

[0030] 13) The source waveguide according to 11), wherein the first input region includes a first coupling element and the second input region includes a second coupling element, each of the first coupling element and the second coupling element further including a grating element of a plurality of grating periods, the grating period being selected based on the refractive index of the material forming the source waveguide.

[0031] 14) The source waveguide according to 11), wherein the source waveguide is associated with a first field of view and a second field of view, each of the first field of view and the second field of view being a function of the refractive index of the material forming the source waveguide.

[0032] 15) The source waveguide according to 14), wherein each of the first field of view and the second field of view is determined based on the tilt angles of the first image light from the first light source and the second image light from the second light source.

[0033] 16) The source waveguide according to 11), wherein the expanded first image light propagates in a first direction and the expanded second image light propagates in a second direction opposite to the first direction.

[0034] 17) The source waveguide according to 11), wherein each of the internally coupled first image light and the internally coupled second image light undergoes total internal reflection within the source waveguide.

[0035] 18) The source waveguide according to 11), wherein each of the internally coupled first image light and the internally coupled second image light undergoes first-order diffraction within the source waveguide.

[0036] 19) The source waveguide according to 11) further includes at least a first source waveguide and a second source waveguide, where the first source waveguide extends along a first dimension, and the second source waveguide extends along a second dimension perpendicular to the first dimension.

[0037] 20) A waveguide display, comprising:

[0038] A first light source configured to emit first image light corresponding to a first part of an image;

[0039] A second light source configured to emit second image light corresponding to a second part of the image that is different from the first part of the image;

[0040] The source waveguide includes a first entrance region, a second entrance region, a first exit region, and a second exit region, and the source waveguide is configured to:

[0041] Couple the first image light within the first entrance region, expand the first image light in at least one dimension, and output the expanded first image light via the first exit region, and

[0042] Couple the second image light within the second entrance region, expand the second image light in a first dimension, and output the expanded second image light via the second exit region; and

[0043] The output waveguide includes a third entrance region and a third exit region, and the output waveguide is configured to couple the first image light and the second image light within the third entrance region, expand the expanded first image light and the expanded second image light in at least one dimension orthogonal to the first dimension to generate a part of a magnified image, and output the part of the magnified image to an eye movement range via the third exit region.

[0044] 21) The waveguide display according to 20), wherein the source waveguide receives the first image light in a first region and receives the second image light in a second region, and the first region and the second region are located at opposite edges of the source waveguide.

[0045] 22) The waveguide display according to 20) or 21), wherein the first entrance region includes a first coupling element, and the second entrance region includes a second coupling element, and each of the first coupling element and the second coupling element further includes a grating element with a plurality of grating periods, and the grating period is selected based on the refractive index of the material forming the source waveguide.

[0046] 23) The waveguide display according to any one of 20) to 22), wherein the source waveguide is associated with a first field of view and a second field of view, and each of the first field of view and the second field of view is a function of the refractive index of the material forming the source waveguide;

[0047] Optionally, wherein each of the first field of view and the second field of view is determined based on the tilt angles of the first image light from the first light source and the second image light from the second light source.

[0048] 24) The waveguide display according to any one of 20) to 23), wherein the expanded first image light propagates in a first direction, and the expanded second image light propagates in a second direction opposite to the first direction.

[0049] 25) The waveguide display according to any one of 20) to 24), wherein each of the internally coupled first image light and the internally coupled second image light undergoes total internal reflection within the source waveguide; and / or

[0050] wherein each of the internally coupled first image light and the internally coupled second image light undergoes first-order diffraction within the source waveguide.

[0051] 26) The waveguide display according to any one of 20) to 25), further comprising a first source waveguide and a second source waveguide, the first source waveguide extending along a first dimension, and the second source waveguide extending along a second dimension perpendicular to the first dimension.

[0052] 27) The waveguide display according to any one of 20) to 26), wherein the third entrance region includes a first coupling element and a second coupling element, and each of the first coupling element and the second coupling element further includes a grating with a plurality of grating periods, and the grating periods are selected based on the refractive index of the material forming the output waveguide.

[0053] 28) A source waveguide, comprising:

[0054] A first entrance region configured to internally couple first image light corresponding to a first portion of an image from a first light source, and the source waveguide expands the first image light in at least one dimension;

[0055] A second entrance region configured to internally couple second image light corresponding to a second portion of the image from a second light source, the second portion of the image being different from the first portion of the image, and the source waveguide expands the second image light in at least one dimension;

[0056] A first exit region configured to output the expanded first image light; and

[0057] A second exit region, configured to output the expanded second image light.

[0058] 29) The source waveguide according to 28), wherein the source waveguide receives the first image light in a first region and the second image light in a second region, and the first region and the second region are located at opposite edges of the source waveguide.

[0059] 30) The source waveguide according to 28) or 29), wherein the first entrance region includes a first coupling element, and the second entrance region includes a second coupling element, and each of the first coupling element and the second coupling element further includes a grating element with a plurality of grating periods, and the grating period is selected based on the refractive index of the material forming the source waveguide.

[0060] 31) The source waveguide according to any one of 28) to 30), wherein the source waveguide is associated with a first field of view and a second field of view, and each of the first field of view and the second field of view is a function of the refractive index of the material forming the source waveguide;

[0061] Optionally, wherein each of the first field of view and the second field of view is determined based on the tilt angles of the first image light from the first light source and the second image light from the second light source.

[0062] 32) The source waveguide according to any one of 28) to 31), wherein the expanded first image light propagates in a first direction, and the expanded second image light propagates in a second direction opposite to the first direction.

[0063] 33) The source waveguide according to any one of 28) to 32), wherein each of the internally coupled first image light and the internally coupled second image light undergoes total internal reflection within the source waveguide; and / or

[0064] wherein each of the internally coupled first image light and the internally coupled second image light undergoes first-order diffraction within the source waveguide.

[0065] 34) The source waveguide according to any one of 28) to 33), further including at least a first source waveguide and a second source waveguide, the first source waveguide being expanded along a first dimension, and the second source waveguide being expanded along a second dimension perpendicular to the first dimension.

[0066] Embodiments according to the present invention are particularly disclosed in the appended claims related to waveguide displays and source waveguides, wherein any feature mentioned in one claim category, e.g., a waveguide display, may also be claimed in another claim category (e.g., a source waveguide, a system, a method, a storage medium, and a computer program product). The dependencies or references in the additional claims are chosen only for formal reasons. However, any subject matter resulting from deliberately referring to any previous claim (in particular multiple dependencies) may also be claimed, such that any combination of claims and their features is disclosed and claimable regardless of the dependencies chosen in the appended claims. The subject matter that may be claimed includes not only combinations of features set forth in the appended claims, but also any other combinations of features in the claims, where each feature mentioned in the claims may be combined with any other feature or combination of other features in the claims. Additionally, any embodiment and feature described or depicted herein may be claimed in a separate claim and / or in any combination with any embodiment or feature described or depicted herein or any feature of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 is a diagram of an NED according to an embodiment.

[0068] Figure 2 is according to an embodiment of Figure 1 a cross-section of the NED shown in

[0069] Figure 3A Shows an isometric view of a tiled waveguide display according to an embodiment.

[0070] Figure 3B Shows according to an embodiment of Figure 3A an alternative view of the tiled waveguide display of

[0071] Figure 3C Shows an isometric view of a waveguide display including a plurality of tiled waveguide assemblies according to an embodiment.

[0072] Figure 4 Shows a cross-section of a tiled waveguide display according to an embodiment.

[0073] Figure 5 is a block diagram of a system including an NED according to an embodiment.

[0074] The drawings depict embodiments of the present disclosure for illustrative purposes only. Those skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods shown herein may be employed without departing from the principles or benefits of the present disclosure described herein. DETAILED DESCRIPTION

[0075] A tiled waveguide display (also referred to as a "waveguide display") is a display that can widen the field of view of the image light emitted from the waveguide display. In some embodiments, the waveguide display is incorporated into a near-eye display (NED), such as part of an artificial reality system. The waveguide display includes a tiled waveguide assembly and an output waveguide. The tiled waveguide assembly includes: a first light source that emits first image light corresponding to a first portion of an image; a second light source that emits second image light corresponding to a second portion of the image, the second portion being different from the first portion of the image; a source waveguide that includes a first entrance region, a second entrance region, a first exit region, and a second exit region; and an output waveguide that includes a third entrance region and a third exit region. Light from each of the first light source and the second light source is coupled into the source waveguide, which emits the image light at specific positions along the source waveguide. Each of the first light source and the second light source can project a one-dimensional line image to an infinite viewing distance through a small exit pupil. The one-dimensional line image can be formed, for example, by using a linear array source and a collimating lens. The source waveguide includes a plurality of grating elements having a constant period determined based on the conditions of total internal reflection and first-order diffraction of the received image light. To form a two-dimensional image, the source waveguide is scanned row by row in a direction orthogonal to the one-dimensional line image projected by the first light source and the second light source. The source waveguide can be tiled around the axis of the projected one-dimensional line image to form a two-dimensional image. The emitted image light is coupled into the output waveguide at a plurality of entrance positions. The output waveguide outputs a plurality of expanded image lights at positions offset from the incident positions, and the position / direction of the emitted expanded image lights is partially based on the orientation of the first light source and the second light source. Each of the plurality of expanded image lights is associated with the field of view of the expanded image light emitted by the output waveguide. In some examples, the total field of view of the tiled waveguide display can be the sum of the fields of view of each of the expanded image lights.

[0076] Embodiments of the present invention may include an artificial reality system or be implemented in combination with an artificial reality system. Artificial reality is a form of reality that has been adjusted in some way before being presented to a user, and it may include, for example, virtual reality (VR), augmented reality (AR), mixed reality (MR), hybrid reality, or some combination and / or derivative thereof. Artificial reality content may include fully generated content or generated content combined with captured (e.g., real-world) content. Artificial reality content may include video, audio, haptic feedback, or some combination thereof, and any of these may be presented in a single channel or multiple channels (such as stereoscopic video that produces a three-dimensional effect for a viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof for creating content in artificial reality and / or otherwise using (e.g., performing activities) in artificial reality. An artificial reality system that provides artificial reality content may be implemented on various platforms, including a head-mounted display (HMD) connected to a host computer system, a stand-alone HMD, a mobile device or computing system, or any other hardware platform capable of providing artificial reality content to one or more viewers.

[0077] Embodiments of the present invention may include an artificial reality system or be implemented in combination with an artificial reality system. Artificial reality is a form of reality that has been adjusted in some way before being presented to a user, and it may include, for example, virtual reality (VR), augmented reality (AR), mixed reality (MR), hybrid reality, or some combination and / or derivative thereof. Artificial reality content may include fully generated content or generated content combined with captured (e.g., real-world) content. Artificial reality content may include video, audio, haptic feedback, or some combination thereof, and any of these may be presented in a single channel or multiple channels (such as stereoscopic video that produces a three-dimensional effect for a viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof for creating content in artificial reality and / or otherwise using (e.g., performing activities) in artificial reality. An artificial reality system that provides artificial reality content may be implemented on various platforms, including an HMD connected to a host computer system, a stand-alone HMD, a mobile device or computing system, or any other hardware platform capable of providing artificial reality content to one or more viewers.

[0078] Figure 1FIG. is a diagram of a near-eye display (NED) 100 according to an embodiment. The NED 100 presents media to a user. Examples of media presented by the NED 100 include one or more images, videos, audio, or some combination thereof. In some embodiments, audio is presented via an external device (e.g., speakers and / or headphones) that receives audio information from the NED 100, a console (not shown), or both and presents audio data based on the audio information. The NED 100 is generally configured to operate as an artificial reality NED. In some embodiments, the NED 100 may utilize computer-generated elements (e.g., images, videos, sounds, etc.) to enhance the view of a physical, real-world environment.

[0079] Figure 1 The NED 100 shown in FIG. includes a frame 105 and a display 110. The frame 105 is coupled to one or more optical elements that together display media to the user. In some embodiments, the frame 105 may represent an eyeglass frame. The display 110 is configured for a user to view content presented by the NED 100. As discussed below in conjunction with Figure 2 FIG., the display 110 includes at least one waveguide display assembly (not shown) for guiding one or more image lights to the user's eyes. The waveguide display assembly includes at least one or more tiled waveguide displays. The waveguide display assembly may also include, for example, a stacked waveguide display, a zoom waveguide display, or some combination thereof. A tiled waveguide display is a display that can widen the field of view of the image light emitted from the waveguide display. A zoom waveguide display is a display that can adjust the depth of focus of the image light emitted from the tiled waveguide display.

[0080] Figure 2 is according to an embodiment of Figure 1 FIG. is a cross-section 200 of the NED 100 shown in FIG.. The display 110 includes at least one display assembly 210. The exit pupil 230 is the position where the eye 220 is located when the user wears the NED 100. For illustrative purposes, Figure 2 FIG. shows the cross-section 200 associated with a single eye 220 and a single display assembly 210, but in an alternative embodiment not shown, another waveguide display assembly separate from the Figure 2 waveguide display assembly 210 shown in FIG. provides image light to the other eye 220 of the user.

[0081] As discussed below in Figure 2As shown in FIG. 0, the display component 210 is configured to direct image light to the eye 220 through the exit pupil 230. The display component 210 may be composed of one or more materials having one or more refractive indices (e.g., plastic, glass, etc.), which effectively minimizes the weight of the NED 100 and broadens the field of view (hereinafter abbreviated as "FOV"). In an alternative configuration, the NED 100 includes one or more optical elements between the display component 210 and the eye 220. The optical elements can be used, for example, to correct aberrations in the image light emitted from the display component 210, magnify the image light emitted from the display component 210, perform some other optical adjustment of the image light emitted from the display component 210, or some combination thereof. Examples of optical elements may include an aperture, a Fresnel lens, a convex lens, a concave lens, a filter, or any other suitable optical element that affects image light.

[0082] In some embodiments, the display component 210 includes one or more tiled waveguide displays. In some embodiments, the tiled waveguide display may be part of a stacked waveguide display or a zoom display. A tiled waveguide display is a display that can widen the field of view of the image light emitted from the waveguide display. A stacked waveguide display is a multicolor display (e.g., a red-green-blue (RGB) display) produced by stacking tiled waveguide displays whose respective monochromatic light sources have different colors.

[0083] Figure 3A An isometric view of a waveguide display 300 according to an embodiment is shown. In some embodiments, the waveguide display 300 (which may also be referred to as a tiled waveguide display) is a component of the NED 100 (e.g., the display component 210). In alternative embodiments, the waveguide display 300 is part of some other NED, or some other system that directs image light to a specific location.

[0084] The waveguide display 300 includes at least a tiled waveguide assembly 310, an output waveguide 320, and a controller 330. For illustrative purposes, Figure 3A The waveguide display 300 associated with a single eye 220 is shown, but in some embodiments, another waveguide display is separate (or partially separated) from the waveguide display 300 and provides image light to the user's other eye. In a partially separated system, one or more components may be shared between the waveguide displays for each eye.

[0085] The tiled waveguide assembly 310 generates image light. The tiled waveguide assembly 310 includes a plurality of light sources, source waveguides, and a controller (e.g., as further described below with respect to Figure 4 The tiled waveguide assembly 310 generates image light 340 and outputs it to the coupling element 350 of the output waveguide 320.

[0086] The output waveguide 320 is an optical waveguide that outputs image light to the user's eye 220. The output waveguide 320 receives the image light 340 at one or more coupling elements 350 and guides the received input image light to one or more decoupling elements 360. In some embodiments, the coupling element 350 couples the image light 340 from the tiled waveguide assembly 310 into the output waveguide 320. The coupling element 350 can be, for example, a diffraction grating, a holographic grating, some other element that couples the image light 340 into the output waveguide 320, or some combination thereof. For example, in an embodiment where the coupling element 350 is a diffraction grating, the pitch of the diffraction grating is selected such that total internal reflection occurs and the image light 340 propagates internally towards the decoupling element 360. For example, the pitch of the diffraction grating can be in the range of 300 nm to 600 nm.

[0087] The decoupling element 360 decouples the total internal reflection image light from the output waveguide 320. The decoupling element 360 can be, for example, a diffraction grating, a holographic grating, some other element that decouples the image light out of the output waveguide 320, or some combination thereof. For example, in an embodiment where the decoupling element 360 is a diffraction grating, the pitch of the diffraction grating is selected such that the incident image light exits the output waveguide 320. For example, the pitch of the diffraction grating can be in the range of 300 nm to 600 nm. The pitch of the diffraction grating is selected such that the image light 340 from multiple light sources undergoes total internal reflection within the output waveguide 320 without leaking through higher order diffraction (e.g., second order reflection). The direction and position of the image light exiting the output waveguide 320 are controlled by changing the direction and position of the image light 340 entering the coupling element 350. In some embodiments, the direction of the image light exiting the output waveguide 320 is the same as the direction of the image light 340. In one example, the position of the image light exiting the output waveguide 320 is controlled by the positions of the multiple light sources of the tiled waveguide assembly 310, the position of the coupling element 350, and the position of the decoupling element 360. Any change in the direction of at least one light source to cover a portion of the total FOV results in the image light exiting the output waveguide 320 covering the same portion of the total FOV. The total FOV is obtained by using multiple light sources that cover the entire FOV. Additionally, the total FOV is a function of the refractive index of the output waveguide 320, the pitch of the diffraction grating, the total number of light sources of the tiled waveguide assembly 310, and the requirement that no leakage light exits the output waveguide 320 through second order diffraction.

[0088] The output waveguide 320 can be composed of one or more materials that facilitate total internal reflection of the image light 340. The output waveguide 320 can be made of, for example, silicon, plastic, glass, or polymer, or some combination thereof. The output waveguide 320 has a relatively small form factor. For example, the output waveguide 320 can be approximately 50 mm wide along the X dimension, 30 mm long along the Y dimension, and 0.5 - 1 mm thick along the Z dimension.

[0089] The controller 330 controls the scanning operation of the tiled waveguide assembly 310. The controller 330 determines the display instructions for the tiled waveguide assembly 310 based on at least one or more display instructions. The display instructions are instructions to render one or more images. In some embodiments, the display instructions can be merely an image file (e.g., a bitmap). The display instructions can be received from, for example, the console of a VR system (e.g., as described below in connection with Figure 5 ). The display instructions are instructions for the tiled waveguide assembly 310 to generate the image light 340. The display instructions can include, for example, an image light source type (e.g., monochromatic, polychromatic), an identifier for a particular light source component, an identifier for a particular tiled waveguide component, a scan rate, a direction of the source, one or more illumination parameters (described below with reference to Figure 4 ), or some combination thereof. The controller 330 receives display instructions that control the direction of the extended light 370 associated with the total field of view of the image light exiting the output waveguide 320. For example, the total field of view can be the sum of the fields of view of each of the multiple light sources of the tiled waveguide assembly 310. In some embodiments, the total field of view can be a weighted sum of the fields of view of each of the multiple light sources, where the weight for each individual field of view is determined based on the amount of overlap between the fields of view from different light sources. In some embodiments, the controller 330 also receives display instructions that include identifier information to select the tiled waveguide assembly that receives the display instructions. The controller 330 includes a combination of hardware, software, and / or firmware not shown here so as not to obscure other aspects of the present disclosure.

[0090] Figure 3B Shows an alternative view of the waveguide display 300 according to an embodiment. Figure 3B is Figure 3A An embodiment of the waveguide display 300, and all the details described above with reference to Figure 3A also apply to Figure 3B . Figure 3B Shows the propagation of one or more reflected image lights 315 through the tiled waveguide assembly 310.

[0091] The tiled waveguide assembly 310 receives image light from each of the light source components 410A and 410B, as described below in connection with Figure 4Detailed description, and each image light is expanded along two opposite directions. The tiled waveguide assembly 310 generates reflected light 315A that undergoes total internal reflection and generally propagates along the negative X dimension. The tiled waveguide assembly 310 generates reflected light 315B that undergoes total internal reflection and generally propagates along the positive X dimension. The propagation direction of the reflected light 315 is based on the pitch of the diffraction grating and the occurrence of total internal reflection of the image light from each of the multiple light sources to obtain a desired range of incident angles to achieve a specific order of diffraction of interest. For example, to achieve positive first-order diffraction (+1), the pitch of the diffraction grating of the coupling element 350 is designed such that the reflected light 315B propagates along the positive X direction. Similarly, the pitch of another diffraction grating of the coupling element 350 is designed such that the reflected light 315A propagates along the negative X direction to achieve negative first-order diffraction (-1). The tiled waveguide assembly 310 generates image light 340 and outputs it to the output waveguide 320. In some embodiments, the image light 340 includes image light 340A and image light 340B. As Figure 3B shown, the image light 340 undergoes total internal reflection at the output waveguide 320. The image light 340 is separated as expanded light 370 by the decoupling element 360 and reaches the eye 220. In some embodiments, the expanded light 370A represents the expanded image light emitted in a direction perpendicular to the surface of the output waveguide 320. The expanded light 370B represents the image light emitted at an angle inclined to the surface of the output waveguide 320. In some configurations, the inclination angle of the expanded image light 370B can be in the range of -30 degrees to +30 degrees.

[0092] Figure 3C is an isometric view of a waveguide display 380 including a plurality of tiled waveguide assemblies 310A and 310B according to an embodiment. Figure 3C is Figure 3A an embodiment of the waveguide display 300. Figure 3C The waveguide display 380 of Figure 3A includes tiled waveguide assemblies 310A, tiled waveguide assemblies 310B, an output waveguide 320B, and a controller 330. The tiled waveguide assemblies 310A and 310B are substantially similar to Figure 3A the tiled waveguide assemblies of Figure 3A The output waveguide 320B is structurally similar to

[0093] the output waveguide 320 of Figure 3A except for the coupling element 350B. The coupling element 350B is Figure 3CIn the example, the tiled waveguide assembly 310A is oriented along the x-dimension, and the tiled waveguide assembly 310B is oriented along the same x-dimension offset from the tiled waveguide assembly 310A. In some embodiments, the offset is determined by the desired size of the eye movement range, the total FOV, and the eye gap distance. The offset is also associated with defining the size of the output area (e.g., 40 mm × 30 mm) needed to give the desired size of the eye movement range for a given total FOV and the eye gap distance.

[0094] Figure 4 FIG. 400 shows a cross-section of a waveguide assembly 300 according to an embodiment. The cross-section 400 of the tiled waveguide assembly 300 includes a source assembly 410A, a source assembly 410B, and a source waveguide 430.

[0095] The source assemblies 410A and 410B generate light according to display instructions from the controller 330. The source assembly 410A includes a source 440A and an optical system 450A. The source 440A is a light source that generates at least coherent or partially coherent image light. The source 440A can be, for example, a laser diode, a vertical cavity surface emitting laser, a light emitting diode, a tunable laser, or some other light source that emits coherent or partially coherent light. The source 440A emits light in the visible band (e.g., from about 390 nm to 700 nm), and it can emit continuous or pulsed light. In some embodiments, the source 440A can be a laser that emits light at a specific wavelength (e.g., 532 nanometers). The source 440A emits light according to one or more illumination parameters received from the controller 330. The illumination parameters are instructions for the source 440A to generate light. The illumination parameters can include, for example, the source wavelength, the pulse rate, the pulse amplitude, the beam type (continuous or pulsed), other parameters that affect the emitted light, or some combination thereof. The source assembly 410B is structurally similar to the source assembly 410A, except for the identifier information in the display instructions from the controller 330.

[0096] In some embodiments, the source assembly 410A and the source assembly 410B are located at opposite ends of the source waveguide 430. The source assembly 410A generates image light that is guided along the negative z-dimension and coupled within the source waveguide 430 to propagate in the negative x-dimension. The source assembly 410B generates image light that is guided along the positive z-dimension and coupled within the source waveguide 430 to propagate in the positive x-dimension.

[0097] The optical system 450 includes one or more optical components that condition the light from the light source 440. Conditioning the light from the light source 440 can include, for example, expanding, collimating, adjusting the direction according to instructions from the controller 330, some other adjustment of the light, or some combination thereof. The one or more optical components can include, for example, lenses, mirrors, apertures, gratings, or some combination thereof. The light emitted from the optical system 450 (and the source assembly 410) is referred to as image light 455. The optical system 450 outputs the image light 455 towards the source waveguide 430.

[0098] The source waveguide 430 is an optical waveguide. The source waveguide 430 can be composed of one or more materials that facilitate total internal reflection of the image light 455. The source waveguide 430 can be composed of, for example, silicon, plastic, glass, or a polymer, a material with a refractive index less than 2, or some combination thereof. The source waveguide 430 has a relatively small form factor. For example, the source waveguide 430 can be approximately 50 mm long along the X dimension, approximately 3 mm wide along the Y dimension, and 0.5 - 1 mm thick along the Z dimension.

[0099] The source waveguide 430 includes a coupling element 460A and a decoupling element 470. The source waveguide 430 receives the image light 455A emitted from the source assembly 410A at the coupling element 460A. The coupling element 460A couples the image light 455A from the light source assembly 410A into the source waveguide 430. The coupling element 460A can be, for example, a diffraction grating, a holographic grating, a reflective surface, a prism structure, a side or edge of the body of the source waveguide 430, some other element that couples the image light 455A into the source waveguide 430, or some combination thereof. For example, in an embodiment where the coupling element 460A is a diffraction grating, the pitch of the diffraction grating is selected such that total internal reflection occurs and the image light 455A propagates internally towards the decoupling element 470. For example, the pitch of the diffraction grating can be in the range of 300 nm to 600 nm.

[0100] The decoupling element 470 separates the total internal reflection image light 455A from the source waveguide 430. In some embodiments, the decoupling element 470 includes a variation (e.g., pitch) in the diffraction grating design such that the decoupling of the image light is more effective in some portions of the diffraction grating for a given range of incident angles. The decoupling element 470 can be, for example, a diffraction grating, a holographic grating, a reflective surface, a prism structure, a side or edge of the body of the source waveguide 430, some other element that decouples the image light from the source waveguide 430, or some combination thereof. For example, in an embodiment where the decoupling element 470 is a diffraction grating, the pitch of the diffraction grating is selected to cause the incident image light to exit the source waveguide 430. The direction of the image light exiting the source waveguide 430 can be changed by changing the direction of the image light leaving the source assembly 410A, changing the direction of the source assembly 410A, or some combination thereof. For example, the pitch of the diffraction grating can be in the range of 300 nm to 600 nm.

[0101] In a typical near-eye display (NED) system using a diffraction grating as a coupling element, the FOV is limited based on meeting two physical conditions: (1) the occurrence of total internal reflection of the image light coupled into the source waveguide 430 and (2) the presence of first-order diffraction of the coupling elements 460A and 460B over the FOV of their respective image sources. Conventional methods used in diffraction grating-based NED systems rely on meeting the above two physical conditions to achieve a large FOV (e.g., greater than 40 degrees) by using materials with a high refractive index, where such methods add significantly heavy and expensive components to the NED system. In contrast, waveguide display 300 relies on splitting the FOV into two half-spaces by separating the coupling elements 460A and 460B, each coupling element being configured to receive image light 455A and image light 455B, respectively. Thus, the pitch value of the diffraction grating within coupling element 460A determines the limit of the first-order diffraction of image light 455A and the limit of the total internal reflection of image light 455A within source waveguide 430.

[0102] Since both coupling element 460A and coupling element 460B reflect the image light to the same decoupling element 470, the pitch of the diffraction grating is the same in order to form a non-distorted image. In this case, the light source is configured to provide half of the FOV, e.g., image light 455A provides from -FOV / 2 to 0 and image light 455B provides from 0 to FOV / 2. In a second example, image light 455A provides from 0 to FOV / 2, and image light 455B provides from -FOV / 2 to 0. The pitch of the diffraction grating is selected such that the FOV corresponding to image light 455A is coupled into the positive first (+1) diffraction order and the FOV of image light 455B is coupled into the negative first (-1) diffraction order. To maximize the brightness of the display presented to the user's eye, the grating profiles of coupling element 460A and coupling element 460B are designed separately to optimize the amount of light coupled into the desired diffraction order. Additionally, the pitch of the diffraction grating can be adjusted to minimize the light leakage of source waveguide 430 by diffracting into higher-order diffraction modes.

[0103] Decoupling element 470 outputs image light 440A and image light 440B to output waveguide 320. The value of the pitch of the diffraction grating within decoupling element 470 is selected to be equal to the value of the pitch of coupling element 460A and coupling element 460B in order to form a non-distorted image of the image light in the display presented to the user's eye. The grating profile is designed such that each time the image light is intercepted using decoupling element 470, the light is partially separated from source waveguide 430. Multiple partial diffractions of the light having decoupling element 470 result in a total expansion along the x-dimension of image light 440.

[0104] The image light 440A leaving the source waveguide 430 expands along at least one dimension (e.g., can be elongated along the x dimension). As referred to above Figure 3A as described, the image light 440 is coupled to the output waveguide 320.

[0105] In some embodiments, the decoupling element 470 has an extended length in the propagation direction of the image light captured within the source waveguide 430. The decoupling element 470 can represent the exit pupil of the source waveguide 430.

[0106] The controller 330 controls the source component 410A by providing display instructions to the source component 410A. The display instructions cause the source component 410A to render light such that the image light leaving the decoupling element 360 of the output waveguide 320 scans out one or more 2D images. For example, the display instructions can cause the tiled waveguide assembly 310 to generate a two-dimensional image from a 1-D array pattern of image light generated by the source component 410 (e.g., using a one-dimensional array of MicroLEDs and collimating lenses). The controller 330 controls the source waveguide 430 by providing scan instructions to the source waveguide 430. The scan instructions cause the source waveguide 430 to perform a scanning operation of the source waveguide 430 according to a scan pattern (e.g., raster, interlaced, etc.). The display instructions control the intensity of the light emitted from the light source 440, and the optical system 450 scans the image by quickly adjusting the direction of the emitted light. If fast enough, the human eye integrates the scanned pattern into a single 2D image. The display instructions also control the rotation direction (e.g., clockwise or counterclockwise) and speed of the source waveguide 430.

[0107] In some configurations, the total field of view of the tiled waveguide display 310 can be determined based on the sum of the fields of view corresponding to the image light 455A and the image light 455B. In a typical NED system, the field of view is limited to half of the total field of view of the tiled waveguide display 310 because there is no splitting of the field of view when using two source components. Additionally, the tiled waveguide display 310 has a relaxation of the form factor of the light source components 410A and 410B because the field of view of each source 440A and 440B is half of the field of view for a waveguide display with a single light source.

[0108] Figure 5 is a block diagram of a system 500 including the NED 100 according to an embodiment. Figure 5 The system 500 shown includes the NED 100, an imaging device 535, and a VR input interface 540, each coupled to a VR console 510. Although Figure 5An example system 500 is shown that includes a NED 100, an imaging device 535, and a VR input interface 540. However, in other embodiments, any number of these components may be included in system 500. For example, there may be multiple NEDs 100, each NED 100 having an associated VR input interface 540 and being monitored by one or more imaging devices 535. Each NED 100, VR input interface 540, and imaging device 535 communicate with the VR console 510. In an alternative configuration, different and / or additional components may be included in system 500. Similarly, the functionality of one or more components may be distributed among the components in a manner different from that described herein. For example, some or all of the functionality of the VR console 510 may be included within the NED 100. Additionally, in some embodiments, the VR system 500 may be modified to include other system environments, such as an AR system environment, or more generally an artificial reality environment.

[0109] The IMU 130 is an electronic device that generates fast calibration data indicative of an estimated position of the NED 100 relative to an initial position of the NED 100 based on measurement signals received from one or more position sensors 125. The position sensors 125 generate one or more measurement signals in response to movement of the NED 100. Examples of the position sensors 125 include: one or more accelerometers, one or more gyroscopes, one or more magnetometers, another suitable type of sensor for detecting movement, a sensor for calibration of the IMU 130, or some combination thereof. The position sensors 125 may be located external to the IMU 130, internal to the IMU 130, or some combination thereof. In Figure 5 the illustrated embodiment, the position sensors 125 are located within the IMU 130, and both the IMU 130 and the position sensors 125 are not visible to the user (e.g., located beneath the outer surface of the NED 100).

[0110] Based on one or more measurement signals generated by one or more position sensors 125, the IMU 130 generates fast calibration data indicative of an estimated position of the NED 100 relative to an initial position of the NED 100. For example, the position sensors 125 include multiple accelerometers to measure translational motion (front / back, up / down, left / right) and multiple gyroscopes to measure rotational motion (e.g., pitch, yaw, roll). In some embodiments, the IMU 130 rapidly samples measurement signals from the various position sensors 125 and calculates an estimated position of the NED 100 based on the sampled data. For example, the IMU 130 integrates over time the measurement signals received from one or more accelerometers to estimate a velocity vector and integrates the velocity vector over time to determine an estimated position of a reference point on the NED 100. The reference point is a point that can be used to describe the position of the NED 100. While the reference point can generally be defined as a point in space; however, in practice, the reference point is defined as a point within the NED 100 (e.g., the reference point 115 representing the center of the IMU 130).

[0111] The imaging device 535 generates slow calibration data based on calibration parameters received from the VR console 510. The imaging device 535 can include one or more cameras, one or more video cameras, one or more filters (e.g., for increasing signal-to-noise ratio), or any combination thereof. The imaging device 535 is configured to detect image light emitted or reflected within the FOV of the imaging device 535. In embodiments where the NED 100 includes passive elements (e.g., retroreflectors), the imaging device 535 can retroreflect the image light to an image light source within the imaging device 535. The slow calibration data is transmitted from the imaging device 535 to the VR console 510, and the imaging device 535 receives one or more calibration parameters from the VR console 510 to adjust one or more imaging parameters (e.g., focal length, focus, frame rate, ISO, sensor temperature, shutter speed, aperture, etc.).

[0112] The VR input interface 540 is a device that allows a user to send action requests to the VR console 510. An action request is a request to perform a specific action. For example, an action request can be to start or end an application or to perform a specific action within an application. The VR input interface 540 can include one or more input devices. Example input devices include: a keyboard, a mouse, a game controller, or any other suitable device for receiving an action request and transmitting the received action request to the VR console 510. The action request received by the VR input interface 540 is transmitted to the VR console 510, which performs the action corresponding to the action request. In some embodiments, the VR input interface 540 can provide haptic feedback to the user based on instructions received from the VR console 510. For example, haptic feedback is provided when an action request is received, or the VR console 510 transmits instructions to the VR input interface 540 such that the VR input interface 540 generates haptic feedback when the VR console 510 performs an action.

[0113] The VR console 510 provides media to the NED 100 for presentation to the user based on information received from one or more of: the imaging device 535, the NED 100, and the VR input interface 540. In Figure 5 the example shown, the VR console 510 includes an application store 545, a tracking module 550, and a VR engine 555. Some embodiments of the VR console 510 have modules different from those described in connection with Figure 5 the modules described. Similarly, the functions further described below can be distributed among the components of the VR console 510 in a manner different from that described herein.

[0114] The application store 545 stores one or more applications for the VR console 510 to execute. An application is a set of instructions that, when executed by a processor, generates content for presentation to the user. The content generated by an application can respond to input received from the user in response to movement through the NED 100 or the VR input interface 540. Examples of applications include: game applications, conferencing applications, video playback applications, or other suitable applications.

[0115] The tracking module 550 uses one or more calibration parameters to calibrate the VR system 500 and can adjust one or more calibration parameters to reduce errors in determining the position of the NED 100. For example, the tracking module 550 adjusts the focus of the imaging device 535 to obtain a more accurate position on the VR headset. Additionally, the calibration performed by the tracking module 550 also takes into account information received from the IMU 530. Further, if tracking of the NED 100 is lost, the tracking module 550 recalibrates some or the entire system environment 500.

[0116] Tracking module 550 tracks the movement of NED 100 using slow calibration information from imaging device 535. Tracking module 550 also determines the position of the reference point of NED 100 using position information from the fast calibration information. Additionally, in some embodiments, tracking module 550 may use portions of the fast calibration information, slow calibration information, or some combination thereof to predict the future position of NED 100. Tracking module 550 provides the estimated or predicted future position of NED 100 to VR engine 555.

[0117] VR engine 555 executes applications within system 500 and receives position information, acceleration information, velocity information, predicted future position, or some combination thereof of NED 100 from tracking module 550. In some embodiments, the information received by VR engine 555 may be used to generate a signal (e.g., a display instruction) to waveguide display assembly 515 that determines the type of content presented to the user. For example, if the received information indicates that the user has looked left, VR engine 555 generates content that mirrors the user's movement in the virtual environment by determining the type of source and waveguide operating in waveguide display assembly 515. For example, VR engine 555 may generate a display instruction that will cause waveguide display assembly 515 to generate content having red, green, and blue. Additionally, VR engine 555 performs an action within an application executing on VR console 510 in response to an action request received from VR input interface 540 and provides feedback to the user for performing the action. The feedback provided may be visual or auditory feedback via NED 100 or tactile feedback via VR input interface 540.

[0118] Other configuration information

[0119] The foregoing description of the embodiments of the present disclosure has been presented for purposes of illustration; it is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Those skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure.

[0120] Some portions of this specification describe embodiments of the present disclosure in terms of algorithms and symbolic representations of operations on information. Those skilled in the data processing arts typically use these algorithmic descriptions and representations to effectively convey the substance of their work to others skilled in the art. Although these operations are described functionally, computationally, or logically, it should be understood that they may be implemented by a computer program, equivalent circuitry, microcode, etc. Additionally, it is sometimes convenient, without loss of generality, to refer to these operational arrangements as modules. The described operations and their associated modules may be embodied as software, firmware, hardware, or any combination thereof.

[0121] Any step, operation, or process described herein can be performed or implemented by one or more hardware or software modules, either alone or in combination with other devices. In one embodiment, the software module is implemented by a computer program product that includes a computer-readable medium containing computer program code that can be executed by a computer processor to perform any or all of the described steps, operations, or processes.

[0122] Embodiments of the present disclosure may also relate to apparatuses for performing the operations herein. The apparatus may be specially constructed for the required purposes and / or it may comprise a general-purpose computing device selectively activated or reconfigured by a computer program stored in a computer. Such a computer program may be stored in a non-transitory tangible computer-readable storage medium, or may be coupled to any type of medium suitable for storing electronic instructions that is coupled to a computer system bus. In addition, any computing system mentioned in the specification may include a single processor, or may be an architecture that employs a multiple-processor design to enhance computing capabilities.

[0123] Embodiments of the present disclosure may also relate to products produced by the computing processes described herein. Such products may include information generated by the computing process, where the information is stored on a non-transitory tangible computer-readable storage medium and may include any embodiment of a computer program product or other data combinations described herein.

[0124] Finally, the language used in the specification has been principally selected for readability and guidance purposes, and it may not have been chosen to delineate or circumscribe the subject matter of the invention. Accordingly, the scope of the present disclosure is intended to be limited not by this detailed description, but rather by any claims issued on the basis hereof. Thus, the disclosure of the embodiments is intended to illustrate rather than limit the scope of the present disclosure, the scope of which is set forth in the appended claims.

Claims

1. A source waveguide assembly, comprising: A waveguide body; A first entrance region configured to internally couple first image light corresponding to a first portion of an image from a first light source into the waveguide body; A second entrance region configured to internally couple second image light corresponding to a second portion of an image from a second light source into the waveguide body, the second portion of the image being different from the first portion of the image; A first exit region configured to output the expanded first image light, the expanded first image light being the first image light expanded in two opposite directions; A second exit region configured to output the expanded second image light, the expanded second image light being the second image light expanded in the two opposite directions; And Wherein the first entrance region and the second entrance region are located at opposite edges of the source waveguide assembly.

2. The source waveguide assembly according to claim 1, wherein The first entrance region includes a first coupling element and the second entrance region includes a second coupling element, each of the first coupling element and the second coupling element including grating elements of a plurality of grating periods, the grating periods being selected based on the refractive index of the material forming the waveguide body.

3. The source waveguide assembly according to claim 1, wherein, The expanded first image light propagates in a first direction of the two opposite directions and the expanded second image light propagates in a second direction of the two opposite directions, the second direction being opposite to the first direction.

4. The source waveguide component according to claim 1, wherein Each of the internally coupled first image light and the internally coupled second image light undergoes total internal reflection within the waveguide body.

5. The source waveguide assembly according to claim 1, wherein, Each of the internally coupled first image light and the internally coupled second image light undergoes first-order diffraction within the waveguide body.

6. The source waveguide assembly according to claim 1, further comprising another waveguide body, the waveguide body expanding light in a first dimension and the another waveguide body expanding light in a second dimension perpendicular to the first dimension.

7. A method of using a source waveguide assembly, the method comprising: Internally coupling first image light corresponding to a first portion of an image from a first light source into a waveguide body at a first entrance region; Internally coupling second image light corresponding to a second portion of an image from a second light source into the waveguide body at a second entrance region, the second portion of the image being different from the first portion of the image; Expanding the first image light in two opposite directions; Expanding the second image light in two opposite directions; Outputting the expanded first image light at a first exit region; Outputting the expanded second image light at a second exit region; And Wherein the first entrance region and the second entrance region are located at opposite edges of the source waveguide assembly.

8. The method according to claim 7, wherein, The first entrance region includes a first coupling element and the second entrance region includes a second coupling element, and each of the first coupling element and the second coupling element includes grating elements of a plurality of grating periods, and the grating periods are selected based on the refractive index of the material forming the waveguide body.

9. The method according to claim 7, wherein The expanded first image light propagates in a first direction of the two opposite directions, and the expanded second image light propagates in a second direction of the two opposite directions, and the second direction is opposite to the first direction.

10. The method according to claim 7, further comprising: The first image light coupled therein undergoes total internal reflection within the waveguide body; and The second image light coupled therein undergoes total internal reflection within the waveguide body.

11. The method according to claim 7, further comprising: The first image light coupled therein undergoes first-order diffraction within the waveguide body; and The second image light coupled therein undergoes first-order diffraction within the waveguide body.

12. The method according to claim 7, further comprising: Expanding light along a first dimension via the waveguide body; and Expanding light along a second dimension perpendicular to the first dimension via another waveguide body.

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