Tiled waveguide displays

Abstract

The present application relates to a tiled waveguide display. 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 with a constant period determined based on the 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 entrance positions. The output waveguide outputs extended image light at a position offset from the entrance position, and the position / direction of the emitted extended image light is based in part on the direction of the light source. Each extended image light is associated with a field of view of the extended image light emitted by the output waveguide.

Description

[0001] This application is a divisional application of an application filed on November 15, 2017, with application number 201780071951.X and invention name “Tiled Waveguide Display”. Technical Field

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

[0003] Near-eye light field displays project images directly into the 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. In addition, NEDs in virtual reality systems and / or augmented reality systems are typically required 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 a relatively large lens, as well as a relatively bulky and heavy NED. Summary of the invention

[0004] The waveguide display is used to present media to a user. The waveguide display includes a first light source emitting first image light corresponding to a first portion of an image; a second light source emitting 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 including a first inlet region, a second inlet region, a first outlet region, and a second outlet region; an output waveguide including a third inlet region and a third outlet region, and a controller generating and providing scanning instructions to the source waveguide.

[0005] The source waveguide couples the first image light in 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 in the second entrance region, expands the second image light in the 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 in 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 the magnified image, and outputs the portion of the magnified image to the eye field 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 the first image light at a first region and receives the second image light at a second region, the first region and the second region being located at 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, each of the first coupling element and the second coupling element including a grating element with a grating period selected based on a refractive index of a material forming the source waveguide.

[0007] This 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 comprising a first entrance region, a second entrance region, a first exit region, and a second exit region, the source waveguide being configured as:

[0012] coupling the first image light within the first entrance region, expanding the first image light in at least one dimension, and outputting the expanded first image light via the first exit region, and

[0013] coupling the second image light in the second entrance region, expanding the second image light in a first dimension, and outputting the expanded second image light through the second exit region; and

[0014] An output waveguide comprising 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 an enlarged image, and output the portion of the enlarged image to an eye range via the third exit region.

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

[0016] 3) A 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, each of the first coupling element and the second coupling element further includes a grating element of multiple grating periods, and the grating period is selected based on the refractive index of the material forming the source waveguide.

[0017] 4) A waveguide display according to 1), wherein the source waveguide is associated with a first field of view and a second field of view, each of which 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 an inclination angle 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 of 1), wherein each of the in-coupled first image light and the in-coupled second image light undergoes total internal reflection within the source waveguide.

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

[0022] 9) The waveguide display according to 1) further includes 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) A waveguide display according to 1), wherein the third entrance region comprises a first coupling element and a second coupling element, each of the first coupling element and the second coupling element further comprising a grating of a plurality of grating periods, the grating periods being selected based on a refractive index of a material forming the output waveguide.

[0024] 11) A source waveguide, comprising:

[0025] a first entrance region configured to incouple first image light corresponding to a first portion of an image from a first light source, the source waveguide expanding the first image light in at least one dimension;

[0026] a second entrance region configured to incouple 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 outlet region configured to output the expanded first image light; and

[0028] The second exit region is 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, and the first region and the second region are located at opposite edges of the source waveguide.

[0030] 13) A source waveguide according to 11), 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 further includes a grating element of multiple grating periods, and the grating period is selected based on the refractive index of the material forming the source waveguide.

[0031] 14) A 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 a tilt angle 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 of 11), wherein each of the in-coupled first image light and the in-coupled second image light undergoes total internal reflection within the source waveguide.

[0035] 18) The source waveguide of 11), wherein each of the in-coupled first image light and the in-coupled second image light undergoes a 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, 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.

[0037] 20) A waveguide display comprising:

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

[0039] a second light source configured to emit second image light corresponding to a second portion of the image different from the first portion of the image;

[0040] The source waveguide comprises a first entrance region, a second entrance region, a first exit region and a second exit region, the source waveguide being configured as:

[0041] coupling the first image light within the first entrance region, expanding the first image light in at least one dimension, and outputting the expanded first image light via the first exit region, and

[0042] coupling the second image light in the second entrance region, expanding the second image light in a first dimension, and outputting 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 in 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 an enlarged image, and output the portion of the enlarged image to the 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 at a first region and receives the second image light at a second region, the first region and the second region being located at opposite edges of the source waveguide.

[0045] 22) A 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, each of the first coupling element and the second coupling element further includes a grating element of multiple grating periods, and the grating period is selected based on the refractive index of the material forming the source waveguide.

[0046] 23) A 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, each of the first field of view and the second field of view being a function of a refractive index of a material forming the source waveguide;

[0047] Optionally, each of the first field of view and the second field of view is determined based on an inclination angle of the first image light from the first light source and the second image light from the second light source.

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

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

[0050] Wherein, each of the in-coupled first image light and the in-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, 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.

[0052] 27) A 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, each of the first coupling element and the second coupling element further includes a grating of multiple grating periods, and the grating period is 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 incouple first image light corresponding to a first portion of an image from a first light source, the source waveguide expanding the first image light in at least one dimension;

[0055] a second entrance region configured to incouple 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, the source waveguide expanding the second image light in at least one dimension;

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

[0057] The second exit region is 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 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.

[0059] 30) A 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, each of the first coupling element and the second coupling element further includes a grating element of multiple grating periods, and the grating period is selected based on the refractive index of the material forming the source waveguide.

[0060] 31) A 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 first field of view, each of the first field of view and the second field of view being a function of a refractive index of a material forming the source waveguide;

[0061] Optionally, each of the first field of view and the second field of view is determined based on an inclination angle of the first image light from the first light source and the second image light from the second light source.

[0062] 32) A 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) A source waveguide according to any one of 28) to 32), wherein each of the in-coupled first image light and the in-coupled second image light undergoes total internal reflection within the source waveguide; and / or

[0064] Wherein, each of the in-coupled first image light and the in-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 includes at least 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.

[0066] Embodiments according to the invention are particularly disclosed in the attached claims relating to waveguide displays and source waveguides, wherein any feature mentioned in one claim category, e.g. waveguide displays, may also be claimed in another claim category (e.g. source waveguides, systems, methods, storage media and computer program products). Dependencies or references in the attached claims have been chosen for formal reasons only. However, any subject matter arising from deliberate reference to any previous claim (in particular multiple dependencies) may also be claimed, such that any combination of claims and their features is disclosed and may be claimed regardless of the dependencies chosen in the attached claims. The subject matter that may be claimed includes not only the combination of features set out in the attached claims, but also any other combination of features in the claims, wherein each feature mentioned in a claim may be combined with any other feature or combination of features in the claims. Furthermore, 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 with any feature of the attached claims. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0068] Figure 2 According to the embodiment Figure 1 Cross section of the NED shown in .

[0069] Figure 3A An isometric view of a tiled waveguide display is shown in accordance with an embodiment.

[0070] Figure 3B According to the embodiment Figure 3A Alternative views of the tiled waveguide display.

[0071] Figure 3C An isometric view of a waveguide display including multiple tiled waveguide assemblies according to an embodiment is shown.

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

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

[0074] The accompanying 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 image light emitted from a waveguide display. In some embodiments, the waveguide display is incorporated into a near eye display (NED), for example, 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 a first image light corresponding to a first portion of an image; a second light source that emits a 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 including a first entrance area, a second entrance area, a first exit area, and a second exit area; and an output waveguide including a third entrance area and a third exit area. Light from each of the first light source and the second light source is coupled into a source waveguide that emits image light at a specific position 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 by, for example, 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 conditions of total internal reflection and first-order diffraction of the received image light. In order to form a two-dimensional image, the source waveguide is scanned line by line 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 multiple entrance positions. The output waveguide outputs a plurality of extended image lights at a position offset from the incident position, and the position / direction of the emitted extended image light is based in part on the orientation of the first light source and the second light source. Each of the plurality of extended image lights is associated with a field of view of the extended 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 extended image light.

[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, which may include, for example, virtual reality (VR), augmented reality (AR), mixed reality (MR), mixed 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, tactile feedback, or some combination thereof, and any of them may be presented in a single channel or multiple channels (such as stereoscopic video that produces a three-dimensional effect to the viewer). In addition, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof for, for example, creating content in artificial reality and / or otherwise using it in artificial reality (e.g., performing activities). Artificial reality systems that provide artificial reality content can be implemented on various platforms, including a head-mounted display (HMD) connected to a host computer system, a standalone 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, which may include, for example, virtual reality (VR), augmented reality (AR), mixed reality (MR), mixed 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, tactile feedback, or some combination thereof, and any of them may be presented in a single channel or multiple channels (such as stereoscopic video that produces a three-dimensional effect to the viewer). In addition, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof for, for example, creating content in artificial reality and / or otherwise using it in artificial reality (e.g., performing activities). Artificial reality systems that provide artificial reality content can be implemented on various platforms, including an HMD connected to a host computer system, an independent HMD, a mobile device or a computing system, or any other hardware platform capable of providing artificial reality content to one or more viewers.

[0078] Figure 1is 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, video, 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 augment a view of a physical, real-world environment with computer-generated elements (e.g., images, video, sound, etc.).

[0079] Figure 1 The NED 100 shown in FIG. 1 includes a frame 105 and a display 110. The frame 105 is coupled to one or more optical elements that together display media to a 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 described below in conjunction with Figure 2 As discussed, the display 110 includes at least one waveguide display assembly (not shown) for directing 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 image light emitted from a waveguide display. A zoom waveguide display is a display that can adjust the depth of focus of image light emitted from a tiled waveguide display.

[0080] Figure 2 According to the embodiment Figure 1 1. A cross section 200 of a NED 100 is shown in FIG. 1. The display 110 includes at least one display component 210. The exit pupil 230 is where the eye 220 is located when the user wears the NED 100. For illustration purposes, Figure 2 The cross section 200 is shown associated with a monocular 220 and a single display assembly 210, but in an alternative embodiment not shown, Figure 2 Another waveguide display assembly separate from the waveguide display assembly 210 is shown to provide image light to the user's other eye 220.

[0081] As shown below Figure 2As shown in , the display assembly 210 is configured to direct image light to the eye 220 through an exit pupil 230. The display assembly 210 can be composed of one or more materials (e.g., plastic, glass, etc.) having one or more refractive indices that effectively minimize the weight of the NED 100 and widen the field of view (hereinafter abbreviated as "FOV"). In an alternative configuration, the NED 100 includes one or more optical elements between the display assembly 210 and the eye 220. The optical elements can be used, for example, to correct aberrations in the image light emitted from the display assembly 210, to amplify the image light emitted from the display assembly 210, some other optical adjustment of the image light emitted from the display assembly 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 the image light.

[0082] In some embodiments, the display assembly 210 includes one or more tiled waveguide displays. In some embodiments, the tiled waveguide display can 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 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 other system that directs display 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 purposes of illustration, Figure 3A Waveguide display 300 is shown associated with a single eye 220, but in some embodiments, another waveguide display is separate (or partially separate) from waveguide display 300 to provide image light to the user's other eye. In a partially separate 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 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 directs 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 embodiments where the coupling element 350 is a diffraction grating, the pitch of the diffraction grating is selected so that total internal reflection occurs and the image light 340 propagates internally toward 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 totally internally reflected image light from the output waveguide 320. The decoupling element 360 may 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 to cause the incident image light to leave the output waveguide 320. For example, the pitch of the diffraction grating may be between 300 nm and 600 nm. The pitch of the diffraction grating is selected so that the image light 340 from the plurality of 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 emitted from 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 emitted from the output waveguide 320 is the same as the direction of the image light 340. In one example, the position of the image light emitted from the output waveguide 320 is controlled by the position 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 causes the image light emitted from the output waveguide 320 to cover the same portion of the total FOV. The total FOV is obtained by using multiple light sources that cover the entire FOV. In addition, 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 be emitted from the output waveguide 320 by second order diffraction.

[0088] The output waveguide 320 can be composed of one or more materials that promote total internal reflection of the image light 340. The output waveguide 320 can be composed of, for example, silicon, plastic, glass, or polymers, 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 of the tiled waveguide assembly 310 based at least on one or more display instructions. The display instructions are instructions for rendering one or more images. In some embodiments, the display instructions may be simply an image file (e.g., a bitmap). The display instructions may be received from, for example, a console of a VR system (e.g., as described below in conjunction with Figure 5 The display instructions are instructions used by the tiled waveguide assembly 310 to generate the image light 340. The display instructions may include, for example, the image light source type (e.g., monochromatic, polychromatic), an identifier for a particular light source assembly, an identifier for a particular tiled waveguide assembly, a scan rate, a direction of the source, one or more illumination parameters (see below). Figure 4 Description) or some combination thereof. The controller 330 receives display instructions to 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 of 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 including identifier information to select the tiled waveguide assembly to receive 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 An alternative view of a waveguide display 300 is shown in accordance with an embodiment. Figure 3B yes Figure 3A Embodiments of the waveguide display 300 and referenced above Figure 3A All details described also apply to Figure 3B . Figure 3B Propagation of one or more reflected image lights 315 through the tiled waveguide assembly 310 is shown.

[0091] The tiled waveguide assembly 310 receives image light from each of the light source assemblies 410A and 410B, and the following Figure 4Detailed description, and expands each image light in two opposite directions. The tiled waveguide assembly 310 produces reflected light 315A that undergoes total internal reflection and generally propagates along the negative X dimension. The tiled waveguide assembly 310 produces 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 the required incident angle range to achieve a specific order of diffraction of interest. For example, in order to achieve a positive first-order diffraction (+1), the pitch of the diffraction grating of the coupling element 350 is designed so 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 so that the reflected light 315A propagates along the negative X direction to achieve a negative first-order diffraction (-1). The tiled waveguide assembly 310 produces image light 340 and outputs it to the output waveguide 320. In some embodiments, image light 340 includes image light 340A and image light 340B. Figure 3B As shown, image light 340 undergoes total internal reflection at output waveguide 320. Image light 340 is separated as expanded light 370 by decoupling element 360 and reaches eye 220. In some embodiments, expanded light 370A represents expanded image light emitted in a direction perpendicular to the surface of output waveguide 320. Expanded light 370B represents image light emitted at an angle oblique to the surface of output waveguide 320. In some configurations, the oblique angle of 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 yes Figure 3A An embodiment of a waveguide display 300 . Figure 3C The waveguide display 380 includes a tiled waveguide assembly 310A, a tiled waveguide assembly 310B, an output waveguide 320B, and a controller 330. The tiled waveguide assemblies 310A and 310B are substantially similar to Figure 3A The output waveguide 320B is similar in structure to the tiled waveguide assembly except for the coupling element 350B. Figure 3A The output waveguide 320. The coupling element 350B is Figure 3A An embodiment of the coupling element 350.

[0093] Tiled waveguide assembly 310A outputs image light 340A to coupling element 350A. Tiled waveguide assembly 310B outputs image light 340B to coupling element 350B. Image lights 340A and 340B are Figure 3A Embodiment of the image light 340. Figure 3CIn the example of , tiled waveguide assembly 310A is oriented along the x-dimension, and tiled waveguide assembly 310B is oriented along the same x-dimension offset from tiled waveguide assembly 310A. In some embodiments, the offset is determined by the desired size of the eye scope, the total FOV, and the eye relief distance. The offset is also associated with the desired size of the eye scope, which defines how large the output area needs to be (e.g., 40 mm×30 mm) to give a given total FOV, and the eye relief distance.

[0094] Figure 4 A cross-section 400 of a waveguide assembly 300 is shown in accordance with 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] Source components 410A and 410B generate light according to display instructions from controller 330. Source component 410A includes source 440A and optical system 450A. Source 440A is a light source that generates at least coherent or partially coherent image light. 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. Source 440A emits light in the visible band (e.g., from about 390nm to 700nm), and it can emit continuous or pulsed light. In some embodiments, source 440A can be a laser that emits light of a specific wavelength (e.g., 532 nanometers). Source 440A emits light according to one or more illumination parameters received from controller 330. Illumination parameters are instructions for source 440A to generate light. Illumination parameters can include, for example, source wavelength, pulse rate, pulse amplitude, beam type (continuous or pulsed), other parameters that affect the emitted light, or some combination thereof. Aside from the identifier information in the display instructions from controller 330, source component 410B is similar in structure to source component 410A.

[0096] In some embodiments, source assembly 410A and source assembly 410B are located at opposite ends of source waveguide 430. Source assembly 410A generates image light that is guided along the negative z dimension and coupled into source waveguide 430 for propagation into the negative x dimension. Source assembly 410B generates image light that is guided along the positive z dimension and coupled into source waveguide 430 for propagation into 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 may include, for example, expansion, collimation, adjustment of direction according to instructions from the controller 330, some other light conditioning, or some combination thereof. The one or more optical components may include, for example, lenses, mirrors, apertures, gratings, or some combination thereof. The light emitted from the optical system 450 (and the source component 410) is referred to as image light 455. The optical system 450 outputs the image light 455 toward the source waveguide 430.

[0098] Source waveguide 430 is an optical waveguide. Source waveguide 430 can be composed of one or more materials that promote total internal reflection of image light 455. Source waveguide 430 can be composed of, for example, silicon, plastic, glass or polymer, a material with a refractive index lower than 2, or some combination thereof. Source waveguide 430 has a relatively small form factor. For example, source waveguide 430 can be about 50 mm long along the X dimension, about 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 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 prismatic 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 so that total internal reflection occurs and the image light 455A propagates internally toward 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 totally internally reflected image light 455A from the source waveguide 430. In some embodiments, the decoupling element 470 includes a change in the diffraction grating design (e.g., pitch) so 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 prismatic 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 embodiments where the decoupling element 470 is a diffraction grating, the pitch of the diffraction grating is selected to cause the incident image light to leave the source waveguide 430. The direction of the image light emitted from the source waveguide 430 can be changed by changing the direction of the image light leaving the source component 410A, changing the direction of the source component 410A, or some combination thereof. For example, the pitch of the diffraction grating can be in the range of 300nm to 600nm.

[0101] In a typical near-eye display (NED) system using a diffraction grating as a coupling element, the limitation of the FOV is based on satisfying 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 on the FOV of their respective image sources. Conventional approaches used by diffraction grating-based NED systems rely on satisfying the above two physical conditions to achieve a large FOV (e.g., above 40 degrees) by using materials with a high refractive index, which adds significantly heavy and expensive components to the NED system. In contrast, the waveguide display 300 relies on dividing the FOV into two half-spaces by separating the coupling elements 460A and 460B, each of which is configured to receive image light 455A and image light 455B, respectively. Therefore, the pitch value of the diffraction grating within the coupling element 460A determines the limit of the first-order diffraction of the image light 455A and the limit of the total internal reflection of the image light 455A within the source waveguide 430.

[0102] Since both coupling element 460A and coupling element 460B reflect image light to the same decoupling element 470, the pitch of the diffraction gratings is the same so that a non-distorted image is formed. In this case, the light source is configured to provide half of the FOV, for example, 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 so 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. In order to maximize the brightness of the display presented to the user's eyes, 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, respectively. Additionally, the pitch of the diffraction grating may be adjusted to minimize light leakage from the source waveguide 430 by diffraction to 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 so as to form an undistorted image for the image light in the display presented to the user's eyes. The grating profile is designed so that each time the image light is intercepted with decoupling element 470, the light is partially separated from source waveguide 430. Multiple partial diffractions of the light with decoupling element 470 result in a total expansion along the x dimension of image light 440.

[0104] Image light 440A exiting source waveguide 430 is expanded in at least one dimension (e.g., may be elongated in the x-dimension). Figure 3A As described above, image light 440 is coupled to output waveguide 320 .

[0105] In some embodiments, the decoupling element 470 has an extended length along the direction of propagation of the image light captured within the source waveguide 430. The decoupling element 470 may represent an 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 so that the image light of the decoupling element 360 leaving the output waveguide 320 scans out one or more 2D images. For example, the display instructions can cause the tiled waveguide component 310 to generate a two-dimensional image from a 1-D array pattern of image light generated by the source component 410 (e.g., a one-dimensional array using MicroLEDs and collimating lenses). The controller 330 controls the source waveguide 430 by providing scanning instructions to the source waveguide 430. The scanning instructions cause the source waveguide 430 to perform a scanning operation of the source waveguide 430 according to a scanning pattern (e.g., raster, interlaced scanning, 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 using two source assemblies. In addition, the tiled waveguide display 310 has a relaxation of the form factor of the light source assemblies 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 NED 100, imaging device 535, and VR input interface 540, each of which is coupled to VR console 510. Figure 5An example system 500 is shown that includes one NED 100, one imaging device 535, and one VR input interface 540, but in other embodiments, any number of these components may be included in the system 500. For example, there may be multiple NEDs 100, each having an associated VR input interface 540 and monitored by one or more imaging devices 535, each NED 100, VR input interface 540, and imaging device 535 communicating with a VR console 510. In alternative configurations, different and / or additional components may be included in the system 500. Similarly, the functionality of one or more components may be distributed between 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 rapid calibration data indicating 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 the one or more measurement signals in response to movement of the NED 100. Examples of position sensors 125 include one or more accelerometers, one or more gyroscopes, one or more magnetometers, another suitable type of sensor that detects motion, a sensor used 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. Figure 5 In the illustrated embodiment, the position sensor 125 is located within the IMU 130, and both the IMU 130 and the position sensor 125 are not visible to a user (eg, are located below an 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 indicating 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 (forward / backward, up / down, left / right) and multiple gyroscopes to measure rotational motion (e.g., pitch, yaw, roll). In some embodiments, the IMU 130 rapidly samples the 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 the measurement signals received from the one or more accelerometers over time 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. A reference point is a point that can be used to describe the position of the NED 100. Although a reference point can generally be defined as a point in space; however, in practice, a reference point is defined as a point within the NED 100 (e.g., a reference point 115 representing the center of the IMU 130).

[0111] The imaging device 535 generates slow calibration data based on the calibration parameters received from the VR console 510. The imaging device 535 may include one or more cameras, one or more video cameras, one or more filters (e.g., for increasing the signal-to-noise ratio), or any combination thereof. The imaging device 535 is configured to detect image light emitted or reflected in the FOV of the imaging device 535. In an embodiment where the NED 100 includes a passive element (e.g., a retroreflector), the imaging device 535 may retroreflect the image light to an image light source in 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 an action request to the VR console 510. An action request is a request to perform a specific action. For example, an action request may be to start or end an application or to perform a specific action within an application. The VR input interface 540 may 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 an action corresponding to the action request. In some embodiments, the VR input interface 540 may provide tactile feedback to the user according to instructions received from the VR console 510. For example, tactile feedback is provided when an action request is received, or the VR console 510 transmits instructions to the VR input interface 540, so that the VR input interface 540 generates tactile feedback when the VR console 510 performs an action.

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

[0114] The application store 545 stores one or more applications for execution by the VR console 510. An application is a set of instructions that, when executed by a processor, generates content for presentation to a user. The content generated by the application may be responsive to input received from the user through movement of the NED 100 or the VR input interface 540. Examples of applications include: gaming 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 helmet. In addition, the calibration performed by the tracking module 550 also takes into account information received from the IMU 530. In addition, if tracking of the NED 100 is lost, the tracking module 550 recalibrates some or all of the system environment 500.

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

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

[0118] Other configuration information

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

[0120] Some parts of this specification describe embodiments of the present disclosure in terms of algorithms and symbolic representations of operations on information. Those skilled in the art of data processing typically use these algorithmic descriptions and representations to effectively convey the essence of their work to other technicians in the field. Although these operations are described functionally, computationally, or logically, they should be understood to be implemented by computer programs or equivalent circuits, microcodes, etc. In addition, without loss of generality, it is sometimes convenient 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 steps, operations or processes described herein may be performed or implemented using one or more hardware or software modules, either alone or in combination with other devices. In one embodiment, the software module is implemented using 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 steps, operations or processes described.

[0122] Embodiments of the present disclosure may also relate to a device for performing the operations herein. The device may be specially constructed for the desired purpose, and / or it may include 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 in any type of medium suitable for storing electronic instructions that may be 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 multiple processor designs to increase computing power.

[0123] Embodiments of the present disclosure may also relate to products produced by the computing process described herein. Such products may include information produced by the computing process, wherein 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 combination described herein.

[0124] Finally, the language used in the specification is selected primarily for readability and instructional purposes, and may not be selected to describe or limit the subject matter of the present invention. Accordingly, the scope of the present disclosure is not intended to be limited by this detailed description, but rather by any claims that issue hereon based on this application. Accordingly, the disclosure of the embodiments is intended to illustrate, but not to limit, the scope of the present disclosure, which is set forth in the claims that follow.

Claims

1. A waveguide display, comprising: a first light source configured to emit a first light; a second light source configured to emit a second light; as well as a first waveguide receiving the first light and the second light and outputting a first image light and a second image light, the waveguide comprising an out-coupling grating configured to couple the first image light out of a first field of view (FOV) and to couple the second image light out of a second FOV, the first image light corresponding to the first light and a first portion of an image, and the second image light corresponding to the second light and a second portion of the image, Wherein each of the first FOV and the second FOV is a function of a refractive index of a material forming the first waveguide.

2. The waveguide display according to claim 1, wherein: The total FOV of the waveguide display is the sum of the first FOV and the second FOV.

3. The waveguide display according to claim 1, wherein: The total FOV of the waveguide display is the sum of the first FOV weighted with a first weight and the second FOV weighted with a second weight, the first weight and the second weight being determined based on an amount of overlap between the first FOV and the second FOV.

4. The waveguide display according to claim 1, wherein: The first waveguide is configured to expand each of the first light and the second light in two opposite directions.

5. The waveguide display according to claim 1, wherein: The first waveguide includes a first coupling element and a second coupling element, the first coupling element couples the first light therein, the second coupling element couples the second light therein, each of the first coupling element and the second coupling element includes a grating with a plurality of grating periods, the grating periods being selected based on a refractive index of a material forming the first waveguide.

6. The waveguide display of claim 1, further comprising a second waveguide configured to guide the first light from the first light source to the first waveguide, and to guide the second light from the second light source to the first waveguide.

7. The waveguide display according to claim 6, wherein: The second waveguide is configured to receive the first light at a first region and to receive the second light at a second region, the first region and the second region being located at opposite edges of the second waveguide.

8. The waveguide display according to claim 7, wherein: The offset between the first area and the second area is determined based on at least one of: a desired size of the eye movement field, a total FOV, and an eye relief distance.

9. The waveguide display according to claim 7, wherein: The first image light and the second image light propagate in opposite directions about an axis, and opposing edges of the second waveguide are oriented along the axis.

10. The waveguide display according to claim 6, wherein: The second waveguide is configured to couple the first light within a first entrance region and to couple the second light within a second entrance region, the first entrance region comprising a first coupling element and the second entrance region comprising a second coupling element, each of the first coupling element and the second coupling element further comprising a grating element of a plurality of grating periods, the grating periods being selected based on a refractive index of a material forming the second waveguide.

11. The waveguide display according to claim 6, wherein: Each of the first light and the second light undergoes total internal reflection or first-order diffraction within the second waveguide.

12. The waveguide display of claim 1, further comprising a second waveguide and a third waveguide, the second waveguide extending along a first dimension, and the third waveguide extending along a second dimension perpendicular to the first dimension.

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