Methods and systems for dual-projector waveguide displays with wide field of view

Abstract

An eyepiece waveguide for an augmented reality display system includes a substrate having a first surface and a second surface and a diffractive input-coupling element. The diffractive input-coupling element is configured to receive an input light beam and couple the input light beam into the substrate as a guided light beam. The eyepiece waveguide further includes a diffractive combiner pupil expander-extractor (CPE) element formed on or in the first surface or the second surface of the substrate. The diffractive CPE element includes a first portion and a second portion divided by an axis. A first set of diffractive optical elements is disposed in the first portion and oriented at a positive angle relative to the axis, and a second set of diffractive optical elements is disposed in the second portion and oriented at a negative angle relative to the axis.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 029,312, filed May 22, 2020, entitled “METHOD AND SYSTEM FOR DUALPROJECTOR WAVEGUIDE DISPLAYS WITH WIDE FIELD OF VIEW,” the entire contents of which are incorporated herein by reference for all purposes. Background Technology

[0003] Modern computing and display technologies have facilitated the development of systems for so-called "virtual reality" or "augmented reality" experiences, in which digitally reproduced images or portions thereof are presented to the user in a way that appears real or can be perceived as real. Virtual reality or "VR" scenarios typically involve presenting digital or virtual image information without transparency to other visual inputs from the actual real world; augmented reality or "AR" scenarios typically involve presenting digital or virtual image information as an enhanced visual representation of the actual world surrounding the user.

[0004] Despite the progress made in these display technologies, there is a need in the field for improved methods and systems related to augmented reality systems (especially display systems). Summary of the Invention

[0005] This invention generally relates to methods and systems associated with transmissive display systems, including wearable displays. More particularly, embodiments of the invention provide methods and systems that offer an extended field of view compared to conventional systems. This invention is applicable to a wide range of applications in computer vision and image display systems.

[0006] As described in this article, by using multiple projectors to create sub-displays that form a combined field of view, the field of view of the eyepiece waveguide (also known as the eyepiece) is increased relative to conventional designs.

[0007] According to an embodiment of the present invention, an eyepiece waveguide for an augmented reality display system is provided. The eyepiece waveguide includes a substrate having a first surface and a second surface. The eyepiece waveguide also includes a diffraction input coupling element formed on or within the first or second surface of the substrate. The diffraction input coupling element is configured to receive an input light beam and couple the input light beam into the substrate as a guide beam. The eyepiece waveguide also includes a diffraction combined pupil expander-extractor (CPE) element formed on or within the first or second surface of the substrate. The diffraction CPE element includes a first portion and a second portion divided by an axis. A first set of diffraction optical elements is disposed in the first portion and oriented at a positive angle relative to the axis, and a second set of diffraction optical elements is disposed in the second portion and oriented at a negative angle relative to the axis.

[0008] According to another embodiment of the present invention, an eyepiece waveguide for an augmented reality display system is provided. The eyepiece waveguide includes a substrate having a first surface and a second surface. The eyepiece waveguide further includes a first diffraction input coupling element formed on or in the first or second surface of the substrate. The first diffraction input coupling element is configured to receive a first input light beam and couple the first input light beam into the substrate as a first guided light beam. The eyepiece waveguide further includes a second diffraction input coupling element formed on or in the first or second surface of the substrate. The second diffraction input coupling element is configured to receive a second input light beam and couple the second input light beam into the substrate as a second guided light beam.

[0009] Furthermore, the eyepiece waveguide also includes a diffractive combined pupil expander-extractor (CPE) element formed on or within a first or second surface of the substrate. The diffractive CPE element is positioned to: receive a first guide beam from a first diffractive input coupling element; receive a second guide beam from a second diffractive input coupling element; couple at least a portion of the first guide beam within a first angular range to form a first field of view of the combined field of view; and couple at least a portion of the second guide beam within a second angular range to form a second field of view of the combined field of view.

[0010] According to a specific embodiment of the present invention, a waveguide display disposed in eyeglasses is provided. The waveguide display includes a first projector, a second projector, a first coupling grating (ICG) optically coupled to the first projector, and a second ICG optically coupled to the second projector. An axis passes through the first ICG and the second ICG. The waveguide display also includes a first diffraction region optically coupled to the first ICG and including a first portion and a second portion, the first portion including a first set of gratings oriented at a positive angle relative to the axis, and the second portion including a second set of gratings oriented at a negative angle relative to the axis. The waveguide display also includes a second diffraction region optically coupled to the second ICG and including a first portion and a second portion, the first portion including a third set of gratings oriented at 180° minus the positive angle relative to the axis, and the second portion including a fourth set of gratings oriented at 180° minus the negative angle relative to the axis.

[0011] According to a specific embodiment of the present invention, a method is provided for operating an eyepiece waveguide defined by a first region and a second region. The method includes guiding light from a first projector to incident on a first coupling grating (ICG). The method further includes diffracting a portion of the light from the first projector into a first portion of the first region of the eyepiece waveguide, into a first portion of the second region, into a second portion of the second region, and out of the eyepiece waveguide. The method also includes diffracting another portion of the light from the first projector into a second portion of the first region of the eyepiece waveguide, into a second portion of the second region, into a first portion of the second region, and out of the eyepiece waveguide. Furthermore, the method includes guiding light from a second projector to incident on a second ICG. The method also includes diffracting a portion of the light from the second projector into a first portion of the second region of the eyepiece waveguide, into a first portion of the first region, into a second portion of the first region, and out of the eyepiece waveguide. The method also includes diffracting another portion of the light from the second projector into a second portion of a second region of the eyepiece waveguide, into a second portion of a first region, into a first portion of the first region, and out of the eyepiece waveguide.

[0012] Compared to conventional technologies, the present invention achieves numerous benefits. For example, embodiments of the invention provide methods and systems that can be used to increase the field of view of a display and improve the user experience. In embodiments, the raster period is selected to produce individual fields of view that are stitched together or partially overlapped to produce a combined field of view. These and other embodiments of the invention, along with their many advantages and features, are described in more detail below and in conjunction with the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a simplified plan view illustrating the eyepiece waveguide according to an embodiment of the present invention.

[0014] Figure 2A This is a simplified cross-sectional view illustrating an eyepiece waveguide with a reduced grating period according to an embodiment of the present invention.

[0015] Figure 2B This is a simplified cross-sectional view illustrating an eyepiece waveguide with an increased grating period according to an embodiment of the present invention.

[0016] Figure 3A This is a simplified plan view illustrating an eyepiece waveguide element with increased grating period and combined field of view according to an embodiment of the present invention.

[0017] Figure 3B This shows the first set of rays used to form the first part of the field of view. Figure 3A The simplified k-space diagram of the operation of the eyepiece waveguide is shown.

[0018] Figure 3C This shows the second set of rays used to form the second part of the field of view. Figure 3A The simplified k-space diagram of the operation of the eyepiece waveguide is shown.

[0019] Figure 3D This shows the field of view. Figure 3A The simplified k-space diagram of the operation of the eyepiece waveguide is shown.

[0020] Figure 3E This shows the alternative field of view. Figure 3A The simplified k-space diagram of the operation of the eyepiece waveguide is shown.

[0021] Figure 3F This illustrates an embodiment of the invention with exemplary light rays. Figure 3A The diagram shows a simplified planar view of the eyepiece waveguide.

[0022] Figure 3G This shows the method used for combining fields of view. Figure 3A The simplified k-space diagram of the operation of the eyepiece waveguide is shown.

[0023] Figure 4A This is a simplified plan view illustrating a multi-projector waveguide display utilizing an eyepiece waveguide with an increased grating period according to an embodiment of the present invention.

[0024] Figure 4B It shows from Figure 4A A simplified planar diagram of the propagation of light from the second projector in a multi-projector waveguide display.

[0025] Figure 4C It is shown Figure 4A The simplified k-space diagram of the operation of the eyepiece waveguide is shown.

[0026] Figure 4D This is a simplified flowchart illustrating a method for operating an eyepiece waveguide defined by a first region and a second region according to an embodiment of the present invention.

[0027] Figure 5A This is a simplified plan view illustrating a multi-projector waveguide display utilizing an eyepiece waveguide with a reduced grating period according to an embodiment of the present invention.

[0028] Figure 5B It is shown Figure 5A The simplified k-space diagram of the operation of the eyepiece waveguide is shown.

[0029] Figure 6A This is a simplified plan view illustrating the elements of a multi-projector waveguide display according to an embodiment of the present invention.

[0030] Figure 6B This is a simplified plan view illustrating the propagation of light in a multi-projector waveguide display according to an embodiment of the present invention.

[0031] Figure 7A This is a simplified plan view illustrating a six-projector waveguide display according to an embodiment of the present invention.

[0032] Figure 7B It is shown Figure 7A A simplified plan view of a single projector element of a six-projector waveguide display is shown.

[0033] Figure 7C It is shown Figure 7B A simplified k-space diagram of the operation of a single projector element is shown.

[0034] Figure 7D It is shown Figure 7A The simplified k-space diagram of the operation of the six-projector waveguide display is shown.

[0035] Figure 8 This is a simplified schematic diagram illustrating the integration of eyeglasses and one or more eyepiece waveguides according to an embodiment of the present invention. Detailed Implementation

[0036] This invention generally relates to methods and systems associated with projection display systems, including wearable displays. More particularly, embodiments of the invention provide methods and systems with an extended field of view compared to conventional systems. The invention is applicable to a variety of applications in computer vision and image display systems, as well as light field projection systems, including stereoscopic systems, systems for delivering light beams to a user's retina, etc.

[0037] Figure 1 This is a simplified plan view illustrating the eyepiece waveguide according to an embodiment of the present invention. Figure 1As shown, the eyepiece waveguide 100 includes a first coupling grating (ICG) 110 and a second ICG 120. A combined pupil expander-extractor (CPE) element 130 is disposed between the first ICG 110 and the second ICG 120. The eyepiece waveguide 100 can achieve an extended field of view that is greater than the range of propagation angles that can be supported in the guided propagation mode in the waveguide thickness direction. Figure 2A and 2B As shown, the eyepiece waveguide 100 has a first surface 132 and a second surface 134. As discussed further below, different diffraction features can be formed on or in the opposing surfaces 132 and 134 of the eyepiece waveguide 100.

[0038] The first ICG 110 is from the first projector 150 (e.g.) Figure 2A (As shown) receives a set of input beams 112, and the second ICG 120 receives from the second projector 160 (also as shown) Figure 2A (As shown) receives a set of input beams 122. In some embodiments, the input beams can propagate through free space from the projector until they are incident on one of the ICGs. Figure 1 As shown, a set of input beams 112 incident on ICG 110 and a set of input beams 122 incident on ICG 120 are angled or tilted relative to the z-axis. ICG 110 and ICG 120 diffract the input beams such that a portion (which may be all) of the input beams enters the guided propagation mode within the eyepiece waveguide 100. The grating lines of ICG 110 and ICG 120 can be oriented to guide the diffracted beams along the x-axis toward CPE 130.

[0039] CPE 130 may include multiple diffraction features exhibiting periodicity along multiple axes. Therefore, CPE 130 may consist of an array of scattering features arranged in a 2D grid. For example, a single scattering feature may be an indentation or protrusion of any shape. The 2D array of scattering features has an associated grating vector derived from the reciprocal lattice of the 2D grid. As an example, CPE 130 may be a 2D diffraction grating composed of intersecting gratings having grating lines repeating along two or more periodic directions. The diffraction features constituting CPE 130 may have a relatively low diffraction efficiency (e.g., 10% or less). Therefore, this low diffraction efficiency allows light beams to be replicated in multiple directions in a spatially distributed manner as they propagate through CPE 130.

[0040] Figure 2A This is a simplified cross-sectional view illustrating an eyepiece waveguide with a reduced grating period according to an embodiment of the present invention. Figure 2AThe design shown causes light incident on one side of the eyepiece waveguide to preferentially couple out on the same side of the eyepiece waveguide, thus providing high efficiency because the light is not lost during propagation through the eyepiece waveguide but couples out after a short propagation path. Furthermore, image sharpness is maintained due to the reduced propagation distance and the number of TIR reflections. Figure 2A As shown, the grating period, inversely correlated with the grating pitch measured between the grating teeth, is selected such that the light rays of a set of input beams 122 of a given wavelength incident on the ICG 120 at an angle greater than zero (i.e., tilted at a positive angle relative to the z-axis) are coupled along a direction centered on the negative x-axis. For this grating with a reduced grating period and an increased grating pitch, if light of a given wavelength is incident normally, the light will be coupled along a direction tilted upward at a positive angle relative to the negative x-axis. Therefore, the reduced grating period utilizes a weaker coupling grating than conventional designs. In other words, if the waveguide angular range is associated with coupling of the angular range centered on normal incidence, the grating period will be reduced such that the angular range tilted at a positive angle relative to the z-axis will be coupled into the same waveguide angular range.

[0041] Therefore, a pyramid defined by a ray 122 tilted at an angle ranging from 0° to +50° relative to the z-axis is coupled into the eyepiece waveguide 101 and undergoes a TIR as the pyramid propagates down the waveguide. To project light incident at an illegal ray angle, the projector 160 can be tilted relative to the eyepiece waveguide, and an illegal ray incident angle can be introduced from the projector, which is oriented perpendicular to the eyepiece waveguide, using optics, etc.

[0042] exist Figure 2A In the illustrated embodiment, the coupling grating 136 has a grating period that matches the grating period of the ICG 120. Therefore, a pyramid 123, ranging from 0° to 50° relative to the z-axis, is coupled out of the eyepiece waveguide 101. In other words, if the range of angles within the waveguide propagates within the eyepiece waveguide 101, the grating period of the coupling grating 136 will decrease, such that a range of angles tilted at a positive angle relative to the z-axis will be coupled out from the same range of angles within the waveguide. Although coupling in and out are shown on opposite surfaces of the eyepiece waveguide 101, this is not required by the invention, and coupling in and out can occur from the same surface.

[0043] Similarly, the grating period of the coupling grating 110 is selected such that light rays of a given wavelength incident on the ICG 110 at an angle range less than zero (i.e., tilted at a negative angle relative to the z-axis) are coupled along a direction centered on the positive x-axis. For this grating with a reduced grating period and an increased grating pitch, if light of a given wavelength is incident normally, the light is coupled along a direction tilted upward at a positive angle relative to the x-axis. Thus, a pyramid defined by light rays 112 tilted at an angle ranging from 0° to -50° relative to the z-axis is coupled into the eyepiece waveguide 101 and undergoes a TIR as the pyramid propagates down the waveguide. To project light incident at an illegal angle, the projector 150 can be tilted relative to the eyepiece waveguide, and an illegal angle of incidence can be introduced from the projector oriented perpendicular to the eyepiece waveguide using optics, etc.

[0044] exist Figure 2A In the illustrated embodiment, the output grating 138 has a grating period that matches the grating period of the input grating 110. Therefore, a pyramid 113, ranging from 0° to -50° relative to the z-axis, is coupled out from the eyepiece waveguide 101. Although input and output are shown on opposite surfaces of the eyepiece waveguide 101, this is not required by the present invention, and input and output can occur from the same surface.

[0045] Therefore, using such Figure 2A The two projectors shown, 150 and 160, generate two fields of view that are thus offset by a predetermined angle relative to the normal of the eyepiece waveguide, thereby producing the stitched field of view shown, i.e., the combined field of view 102. Therefore, embodiments of the invention utilize a waveguide whose carrying capacity (i.e., based on the TIR angle) is fully utilized in combination with non-linear incident light and modifications to the grating period from conventional designs to produce the stitched field of view.

[0046] Therefore, using a design characterized by a reduced grating period, light injected at the ICG located on one side of the eyepiece waveguide preferentially couples out on the same side of the eyepiece waveguide to form a sub-display with a combined field of view. For example... Figure 2AAs shown, light rays 122, defined as a pyramid tilted at an angle ranging from 0° to 50° relative to the z-axis, are coupled into the eyepiece waveguide 101 and output as light rays in the pyramid 123, thereby forming a first sub-display covering an angular range from 0° to 50° relative to the z-axis. Simultaneously, light rays 112, defined as a pyramid tilted at an angle ranging from 0° to -50° relative to the z-axis, are coupled into the eyepiece waveguide 101 and output as light rays in the pyramid 113, thereby forming a second sub-display covering an angular range from 0° to -50° relative to the z-axis. A combined field of view 102 is formed by splicing the first and second sub-displays to form a combined field of view 102 equal to 100° covering an angular range from -50° to 50°.

[0047] Using polymer eyepiece waveguide materials, including polymers with a refractive index of ~1.75, conventional eyepiece waveguide designs can achieve a field of view of ~50°. By utilizing... Figure 2A The eyepiece waveguide shown, with its increased grating period, uses a tilted, symmetrical projector that is tilted to produce an incident angle, and matches the increased grating period used for the coupling-in and coupling-out gratings, resulting in a symmetrical tilt of the output light and a stitched field of view, enabling a combined field of view up to 100° in a stitched configuration. Alternatively, a combined field of view ranging between 50° and 100° can be achieved in a partially overlapping configuration.

[0048] although Figure 2A The illustration shows light coupled into and out of an eyepiece waveguide at a given angle, but this is not required by the present invention. In other embodiments, the grating periods of the coupling grating and the coupling grating are modified to enable coupling into a first pyramid centered at a first angle and coupling out into a second pyramid centered at a second angle different from the first angle. Many variations, modifications, and alternatives will be recognized by those skilled in the art.

[0049] exist Figure 2AThe structure of the grating used in the illustrated embodiment can vary in different regions of the eyepiece waveguide. In this design with a reduced grating period, a blazed grating can be used to reduce the coupling efficiency. As an example, grating 136 can be blazed to increase its efficiency for light received from projector 160, and grating 138 can be blazed to increase its efficiency for light received from projector 150. This blazed grating design will result in less light from projector 150 being coupled out by grating 136, and less light from projector 160 being coupled out by grating 138. In the central region between gratings 136 and 138, the grating structure can be hierarchically arranged to begin with one blazed grating profile and end with another blazed grating profile having a binary grating in the central region. In addition to blazed gratings, other diffractive surfaces can be utilized, particularly those characterized by different diffraction efficiencies depending on the direction of incident light, including metasurfaces and metamaterials, volumetric phase holograms, edged gratings, etc. Many variations, modifications, and substitutions will be recognized by those skilled in the art.

[0050] Figure 2B This is a simplified cross-sectional view illustrating an eyepiece waveguide with an increased grating period according to an embodiment of the present invention. Figure 2B The design shown causes light incident on one side of the eyepiece waveguide to preferentially couple out on the opposite side of the eyepiece waveguide. Using a design with an increased grating period, the spatial spacing between the coupling grating and the coupling grating can be reduced, while providing spatial expansion for the image size, thereby reducing the size of the eyepiece waveguide. Figure 2B As shown, the grating period, inversely proportional to the grating pitch 122 measured between the grating teeth, is selected such that a ray 122 of a given wavelength incident on the ICG 154 at an angle greater than zero (i.e., tilted at a positive angle relative to the z-axis) is coupled along a direction centered on the positive x-axis. For this grating with an increased grating period and a decreased grating pitch, if light of a given wavelength is incident normally, the light will be coupled along a direction tilted upwards at a positive angle relative to the positive x-axis. Thus, the increased grating period utilizes a stronger coupling grating than conventional designs. Therefore, a pyramid defined by the ray 122 tilted at an angle ranging from 0° to +50° relative to the z-axis is coupled into the eyepiece waveguide 104 and undergoes a TIR as the pyramid propagates downwards along the waveguide. To project light incident at an illegal angle, the projector 160 can be tilted relative to the eyepiece waveguide, and an illegal angle of incidence can be introduced from the projector oriented perpendicular to the eyepiece waveguide using optics, etc.

[0051] exist Figure 2BIn the illustrated embodiment, the coupling grating 156 has a grating period that matches the grating period of the ICG 154. Therefore, a pyramid 123, ranging from 0° to 50° relative to the z-axis, is coupled out from the eyepiece waveguide 104. Although coupling in and out are shown on opposite surfaces of the eyepiece waveguide 104, this is not required by the present invention, and coupling in and out can occur from the same surface.

[0052] Similarly, the grating period of the coupling grating (ICG) 164 is selected such that light rays 112 of a given wavelength incident on the ICG 164 at an angle range less than zero (i.e., tilted at a negative angle relative to the z-axis) are coupled along a direction centered on the negative x-axis. For this grating with an increased grating period and a decreased grating pitch, if light of a given wavelength is incident normally, the light will be coupled along a direction tilted upward at a positive angle relative to the negative x-axis. Thus, a pyramid defined by light rays 112 tilted at an angle ranging from 0° to -50° relative to the z-axis is coupled into the eyepiece waveguide 104 and undergoes a TIR as the pyramid propagates down the waveguide. To project light incident at an illegal angle, the projector 150 can be tilted relative to the eyepiece waveguide, and an illegal angle of incidence can be introduced from the projector, which is oriented perpendicular to the eyepiece waveguide, using optics, etc.

[0053] exist Figure 2B In the illustrated embodiment, the output grating 166 has a grating period that matches the grating period of the input grating 164. Therefore, a pyramid 113, ranging from 0° to -50° relative to the z-axis, is coupled out from the eyepiece waveguide 104. Although input and output are shown on opposite surfaces of the eyepiece waveguide 104, this is not required by the present invention, and input and output can occur from the same surface.

[0054] Therefore, using such Figure 2B The two projectors shown, 150 and 160, generate two fields of view that are thus offset by a predetermined angle relative to the normal of the eyepiece waveguide, thereby producing the stitched field of view shown, i.e., the combined field of view 105. Therefore, embodiments of the invention utilize a waveguide in which the waveguide's carrying capacity (i.e., based on the TIR angle) is fully utilized in combination with non-linear incident light and modifications to the grating period from conventional designs to produce the stitched field of view.

[0055] Therefore, using a design characterized by increased grating period, light injected at the ICG on one side of the eyepiece waveguide propagates to the other side where the light is coupled out of the eyepiece waveguide, forming a sub-display with a combined field of view. For example... Figure 2BAs shown, light ray 122, defined as a pyramid tilted at an angle ranging from 0° to 50° relative to the z-axis, is coupled into the eyepiece waveguide 104 and output as light ray 123, thereby forming a first sub-display covering an angular range of 0° to 50° relative to the z-axis. Simultaneously, light ray 112, defined as a pyramid tilted at an angle ranging from 0° to -50° relative to the z-axis, is coupled into the eyepiece waveguide 104 and output as light ray 113, thereby forming a second sub-display covering an angular range of 0° to -50° relative to the z-axis. A combined field of view 105 is formed by splicing the first and second sub-displays to form a combined field of view 105 equal to 100° covering an angular range of -50° to 50°.

[0056] Using polymer eyepiece waveguide materials, including polymers with a refractive index of ~1.75, conventional eyepiece waveguide designs can achieve a field of view of ~50°. By utilizing... Figure 2B The eyepiece waveguide shown, with its increased grating period, uses a tilted, symmetrical projector that is tilted to produce an incident angle, and matches the increased grating period used for the coupling-in and coupling-out gratings, resulting in a symmetrical tilt of the output light and a stitched field of view, enabling a combined field of view up to 100° in a stitched configuration. Alternatively, a combined field of view ranging between 50° and 100° can be achieved in a partially overlapping configuration.

[0057] although Figure 2B The illustration shows light coupled into and out of an eyepiece waveguide at a given angle, but this is not required by the present invention. In other embodiments, the grating periods of the coupling grating and the coupling grating are modified to enable coupling into a first pyramid centered at a first angle and coupling out into a second pyramid centered at a second angle different from the first angle. Many variations, modifications, and alternatives will be recognized by those skilled in the art.

[0058] exist Figure 2B The structure of the grating used in the illustrated embodiment can vary in different regions of the eyepiece waveguide. In this design with increased grating period, a blazed grating can be used to increase coupling efficiency. As an example, grating 156 can be blazed to increase its efficiency for light received from projector 160, and grating 166 can be blazed to increase its efficiency for light received from projector 150. This blazed grating design will result in less light from projector 150 being coupled out by grating 156, and less light from projector 160 being coupled out by grating 166. In the central region between gratings 156 and grating 166, the grating structure can be graded to begin with one blazed grating profile and end with another blazed grating profile having a binary grating in the central region. Many variations, modifications, and substitutions will be recognized by those skilled in the art.

[0059] Figure 3A This is a simplified plan view illustrating an eyepiece waveguide element with increased grating period and combined field of view according to an embodiment of the present invention. Figure 3A The image shows the propagation and diffraction of light in a waveguide display and the resulting field of view. (Example:) Figure 3A As shown, the diffraction of the input light by the ICG 305 causes the light to diffract into the plane of the waveguide and propagate within the plane of the waveguide, as indicated by rays 311 and 315. As will be described, the ray represented by ray 311 and the ray represented by ray 315 will result in a field of view 310 including a first portion 310a and a second portion 310b (as shown). Figure 3D The generation of (as shown).

[0060] Ray 311, after diffracting from ICG 305, propagates upwards and to the right, and then diffracts again from the grating at the top of the waveguide, producing ray 312, which propagates downwards and to the right. This OPE diffraction event is caused by... Figure 3B Arrow 322 indicates that ray 312 propagates in the waveguide and is diffracted from the grating in the lower part of the waveguide, producing a coupling event 313. The coupled ray 314 is shown propagating upward from the lower part of the waveguide toward the user, thereby producing a first portion 310a of the field of view 310 associated with the lower part of the user's field of view.

[0061] Simultaneously, ray 315 propagates downwards and to the right near axis 301, and diffracts from the grating in the lower part of the waveguide near axis 301, producing ray 316, which propagates upwards and to the right. This OPE diffraction event is caused by... Figure 3C Arrow 332 indicates that ray 316 propagates in the waveguide and is diffracted from the grating in the upper part of the waveguide near axis 301, producing a coupling event 317. The coupled ray 318 is shown propagating downwards towards the user from the upper part of the waveguide near axis 301, thereby producing the lower part 310b of the field of view 310.

[0062] Therefore, the field of view 310 includes a first portion 310a associated with ray 311 and a second portion 310b associated with ray 315. As will be apparent to those skilled in the art, a ray coupled at an intermediate angle and operable to propagate in the waveguide will fill the field of view 310.

[0063] Figure 3B This shows the first set of rays used to form the first part of the field of view. Figure 3A The simplified k-space diagram of the eyepiece waveguide operation is shown. Figure 3BAs shown, the first portion 310a of the field of view 310 travels through the k-space diagram as indicated by positions 326 and 328, such that it is not intercepted by the boundaries of the loops corresponding to the waveguide in-plane angles defined by the circles at n = 1.0 and n = 1.75. Therefore, in-plane and out-of-plane diffraction of the eyepiece waveguide results in travel through the region propagating inside the eyepiece waveguide in the k-space diagram.

[0064] refer to Figure 3B The diffraction from ICG 305 is indicated by arrow 320, which represents the grating vector that translates the first part 310a of the field of view into the waveguide region of the k-space diagram, as shown at position 326. Figure 3A As shown, the OPE diffraction event generated by the diffraction of ray 311 to produce ray 312 is caused by... Figure 3B Arrow 322 indicates that the first part 310a of the field of view is translated from position 326 to position 328 in the waveguide-inner region of the k-space diagram, which is also in the waveguide-inner region of the k-space diagram. The EPE coupling event 313, generated by the diffraction of ray 312 to produce the coupled ray 314, is... Figure 3B Arrow 324 indicates that the first part 310a of the field of view is translated from position 328 in the waveguide inner region of the k-space diagram to the eye space region of the k-space diagram associated with the first part 310a of the field of view.

[0065] Therefore, as Figure 3B As indicated by the k-space diagram, the light in the lower part of the user's field of view is formed by light rays propagating upwards from the lower part of the waveguide toward the user, thereby producing the first part 310a of the field of view 310.

[0066] Figure 3B The k-space diagram in the figure shows that Figure 3A The eyepiece waveguide design shown has a grating spacing along axis 302 characterized by an increased grating period, because the center of field of view 310a is shifted by a distance measured along axis 302 as a result of OPE and EPP diffraction events. This distance is greater than the distance from the origin to the location of the field of view center, indicated at position 328 along axis 302. In other words, reference... Figure 3B The distance L measured along axis 302 is greater than the distance D. In contrast, considering the magnitude of the translation along axis 301, the distance from the origin to point 303 is equal to the distance the center of field of view 310a is translated along axis 301, because the grating spacing along axis 301 is not characterized by an increasing or decreasing grating period.

[0067] Therefore, using an eyepiece waveguide design comprising grating lines oriented at ~60° to each other, light can flow along three distinct grating vectors in the k-space diagram: arrow 320 represents the grating vector aligned with axis 301, which represents diffraction in the plane of the ICG to the eyepiece waveguide, and translates the field of view 310a to position 326; arrow 322 represents the grating vector oriented at ~-120° to axis 301, and translates the field of view at position 326 to position 328; and arrow 324 represents the grating vector oriented at ~60° to axis 301, and translates the field of view at position 328 to field of view 310a. Since positions 326 and 328 are within the loop of the waveguide's inner angle, light diffracted along these three distinct grating vectors will remain within the eyepiece waveguide.

[0068] Figure 3C This shows the second set of rays used to form the second part of the field of view. Figure 3A The simplified k-space diagram of the eyepiece waveguide operation is shown. (Reference) Figure 3A Ray 315, after diffracting from ICG 305, propagates downwards and to the right near axis 301, ultimately leading to the generation of coupled ray 318. (As...) Figure 3C As shown, the diffraction from ICG 305 is indicated by arrow 330. The second portion 310b of the field of view is shifted to the waveguide region of the k-space diagram, as shown at position 336. Figure 3A As shown, the OPE diffraction event generated by the diffraction of ray 315 is caused by... Figure 3C Arrow 332 indicates that the second part 310b of the field of view is translated from position 336 to position 338 in the waveguide-inner region of the k-space diagram, which is also in the waveguide-inner region of the k-space diagram. The EPE coupling event 317, generated by the diffraction of ray 316 to produce the coupled ray 318, is... Figure 3C Arrow 334 indicates that the second part 310b of the field of view is translated from position 338 in the waveguide inner region of the k-space diagram to the eye space region of the k-space diagram associated with the second part 310b of the field of view.

[0069] Such as about Figure 3B As discussed in the first part 310 shown, the second part 310b of the field of view 310 travels through the k-space diagram, as indicated by positions 336 and 338, such that it is not intercepted by the boundaries of the loops corresponding to the waveguide in-plane angles defined by the circles at n = 1.0 and n = 1.75. Therefore, in-plane and out-of-plane diffraction of the eyepiece waveguide results in travel through the region propagating inside the eyepiece waveguide in the k-space diagram.

[0070] Figure 3D This shows the field of view. Figure 3A The simplified k-space diagram of the eyepiece waveguide operation is shown. Figure 3D The k-space diagram shown illustrates the first portion 310a and the second portion 310b of the field of view 310. (As for...) Figures 3A to 3C The light rays discussed, diffracted into the waveguide by ICG and generally propagating upwards to the right and downwards at a small angle relative to axis 301, can be represented in k-space by translating field of view 310 to positions 326 and 336, representing their propagation in the waveguide. The OPE interaction, indicated by arrows 322 and 332, represents propagation from the upper part of the waveguide to the lower part and from the lower part of the waveguide to the upper part, respectively. Finally, the EPE interaction is represented by coupling out, which is represented by field of view 310 at an angle in the eye-space region.

[0071] Therefore, the field of view 310 includes a first portion 310a associated with ray 311 and a second portion 310b associated with ray 315. As will be apparent to those skilled in the art, a ray coupled at an intermediate angle and operable to propagate in the waveguide will fill the field of view 310.

[0072] Figure 3E This shows the alternative field of view. Figure 3A The simplified k-space diagram of the eyepiece waveguide operation is shown. Figure 3E In this waveguide, as light propagates downwards towards the user from the upper part, a field of view 340 is formed that is associated with the lower part of the user's field of view. Therefore, the field of view 340 is a mirror image of the field of view 310 with respect to axis 301.

[0073] refer to Figure 3E This shows the first portion 340a and the second portion 340b of the field of view 340. Similar to... Figures 3A to 3D The operation shown, and in a mirror manner, the light rays diffracted into the waveguide via ICG and generally propagating downwards to the right and upwards at a small angle relative to axis 301, can be represented in k-space by translating the field of view 340 to positions 346 and 356, representing the propagation in the waveguide. The OPE interaction results in translations of the first portion to position 348 and the second portion to position 358, respectively, because these propagation angles within the waveguide are supported by the waveguide. Finally, the EPE interaction is represented by the coupling out, which is represented by the field of view 340 at the angle in the eye-space region.

[0074] Therefore, as a mirror image of field of view 310, field of view 340 includes [the image of field of view 340]. Figure 3A The first part 340a associated with the light rays propagating downwards and to the right, and related to... Figure 3A The second portion 340b is associated with the light rays propagating from the center to the upper right. As will be apparent to those skilled in the art, light rays coupled at an intermediate angle and operable to propagate in the waveguide will fill the field of view 340.

[0075] Figure 3F This illustrates an embodiment of the invention with exemplary light rays. Figure 3A The diagram shows a simplified planar view of the eyepiece waveguide. Figure 3F The diagram shows representative rays associated with the first and second portions of fields of view 310 and 340. (See also: Regarding...) Figure 3A The discussed ray 311, after diffracting from ICG 305, propagates upward to the right and is diffracted from the grating at the top of the waveguide, producing a ray propagating downward to the right (OPE interaction). When this ray interacts with the grating in the lower part of the waveguide, an EPE event occurs, causing ray 314 to couple out, propagating upward from the lower part of the waveguide towards the user, thus producing the first portion 310a of the field of view 310. Simultaneously, ray 315 propagates downward to the right near axis 301 and is diffracted from the grating in the lower part of the waveguide near axis 301, producing a ray propagating upward to the right (OPE interaction). When this ray interacts with the grating at the top of the waveguide, an EPE event occurs, causing ray 318 to couple out, propagating downward from the top of the waveguide towards the user, thus producing the second portion 310b of the field of view 310.

[0076] In a mirror manner, ray 381 propagates downward to the right and, as an OPE diffraction event, is diffracted by a grating in the lower part of the waveguide, generating ray 382, ​​which propagates upward to the right. Ray 382 propagates in the waveguide and, as an OPE diffraction event, is diffracted by a grating in the upper part of the waveguide, generating coupling event 383. Coupling ray 384 is shown propagating downward from the upper part of the waveguide toward the user, thereby generating a first portion 340a of the field of view 340 associated with the upper part of the user's field of view. Simultaneously, ray 385 propagates upward to the right near axis 301 and, as an OPE diffraction event, is diffracted by a grating in the upper part of the waveguide near axis 301, generating ray 386, which propagates downward to the right. Ray 386 propagates in the waveguide and, as an OPE diffraction event, is diffracted by a grating in the lower part of the waveguide near axis 301, generating coupling event 387. The coupled ray 388 is shown propagating upward toward the user from the lower part of the waveguide near axis 301, thereby producing a second portion 340b of the field of view 340.

[0077] Therefore, the field of view 340 includes a first portion 340a associated with ray 381 and a second portion 340b associated with ray 385. As will be apparent to those skilled in the art, rays coupled at an intermediate angle and operable to propagate in the waveguide will fill the field of view 340.

[0078] Furthermore, although only four OPE interactions and four EPE interactions are shown for clarity, it should be understood that rays 311 / 385 and 315 / 381 will experience OPE interactions at the top and bottom of the entire waveguide, respectively. Similarly, rays 312 / 386 and 316 / 382 will experience EPE interactions at the bottom and top of the waveguide, respectively. Therefore, coupling events will occur throughout the entire waveguide, and coupling events 313 / 387 and 317 / 383 are merely exemplary. Thus, the coupling rays distributed across the waveguide will contribute to the generation of fields of view 310 and 340.

[0079] It should be noted that, Figure 3F In the illustrated embodiment, the gratings in the top and bottom of the waveguide intersect at axis 301 without overlapping. However, this is not required by the invention, and in some other embodiments, the gratings overlap at a predetermined distance above and / or below axis 301 at a location along axis 302. This overlapping region allows light propagating into the top of the waveguide to undergo OPE interaction with the grating originating from the bottom of the waveguide and extending into the top of the waveguide within the overlapping region. Continuing the example, light propagating into the top of the waveguide and undergoing OPE interaction in the overlapping region will diffract upwards into the top and may undergo EPE interaction, which will result in a coupling event that enhances the output associated with field of view 340. Similarly, light propagating into the bottom of the waveguide may undergo OPE interaction with the grating originating from the top of the waveguide and extending into the overlapping region within the bottom of the waveguide. These rays, which propagate to the bottom of the waveguide and undergo OPE interaction in the overlapping region, will diffract downwards to the bottom and may undergo EPE interaction, which will result in a coupling event that will enhance the output associated with field of view 310.

[0080] Such as about Figure 3G As described, utilizing Figure 3A and 3F The waveguide design shown forms a combined field of view by overlapping field of view 310 and field of view 340. Therefore, although each field of view individually provides a field of view of ~50° x ~40° (i.e., vertical x horizontal), the overlapping field of view provides a combined field of view of ~80° x ~40°, thereby significantly improving the user experience.

[0081] Figure 3G This shows the method used for combining fields of view. Figure 3A The simplified k-space diagram of the eyepiece waveguide operation is shown. (Reference) Figure 3GThe combined field of view 350 is formed by the overlap between field of view 310 and field of view 340. Although translations of field of view 310 to positions 360 and 361 are shown for clarity, it should be understood that a portion of this field of view is translated through position 366 in k-space. Similarly, translations of field of view 340 to positions 365 and 366 are shown for clarity, but it should be understood that a portion of this field of view is translated through position 361 in k-space. Figure 3G As shown, field of view 310 has a spatial range of approximately 50° vertically × -40° horizontally. Similarly, field of view 340 has a similar spatial range. Due to the overlap between these fields of view, a combined field of view is formed, characterized by a larger extended field of view of approximately 80° x 40°. Therefore, using the embodiment of the present invention that utilizes a single projector and a grating characterized by an increased grating period in one dimension enables waveguide displays with an increased field of view.

[0082] Figure 4A This is a simplified plan view illustrating a multi-projector waveguide display 400 utilizing an eyepiece waveguide with an increased grating period according to an embodiment of the present invention. Similar to... Figure 2B The method discussed involves the diffraction of the input light by the ICG 405, causing the light to diffract into the plane of the waveguide and propagate within it, as indicated by rays 411 and 415. As will be described, the rays represented by ray 411 and ray 415 will result in the generation of a field of view comprising two parts, each associated with the rays initially propagating into the upper half and lower half of the eyepiece waveguide, respectively.

[0083] The multi-projector waveguide display 400 includes a first region 403 and a second region 404, wherein the first region 403 is circular in this embodiment, and the second region 404 is also circular in this embodiment. The first region 403 and the second region 404 overlap to form an overlapping region 406. Figure 4A In this configuration, the overlapping region 406 is located at the midpoint between ICG 405 and ICG 425. The first region 403 includes a first portion defined by the upper semicircle of the first region 403 and a second portion defined by the lower semicircle of the first region 403. Similarly, the second region 404 includes a first portion defined by the upper semicircle of the second region 404 and a second portion defined by the lower semicircle of the second region 404. The overlapping region 406 is formed by the overlap of the first portion of the first region and the first portion of the second region, and by the overlap of the second portion of the first region and the second portion of the second region. (Regarding...) Figure 6A Additional descriptions related to the eyepiece waveguide of a multi-projector waveguide display are provided.

[0084] Ray 411 propagates upward and to the right after diffraction from ICG 405 and is diffracted from the grating at the top of the waveguide, producing ray 412, which propagates downward and to the right. Ray 412 propagates within the waveguide and is diffracted from the grating in the lower part of the waveguide, producing a coupling event 413. The coupled ray 414 is shown propagating upward from the lower part of the waveguide toward the user, thereby producing a portion of the field of view associated with the lower part of the user's field of view.

[0085] Simultaneously, ray 415 propagates downward to the right near axis 401 and is diffracted by a grating in the lower part of the waveguide near axis 401, producing ray 416, which propagates upward to the right. Ray 416 propagates in the waveguide and is diffracted by a grating in the upper part of the waveguide near axis 401, producing a coupling event 417. The coupled ray 418 is shown propagating downward towards the user from the upper part of the waveguide near axis 401, thereby creating the lower part of the field of view. As will be apparent to those skilled in the art, rays coupled at an intermediate angle and operable to propagate in the waveguide will fill the field of view. Reference Figure 4C The field of view 410 is generated by the rays shown by rays 411 and 415.

[0086] Figure 4B It shows from Figure 4A A simplified planar diagram of the propagation of light from the second projector in a multi-projector waveguide display is shown. As will be apparent to those skilled in the art, regarding... Figure 4B The operation of the eyepiece waveguide discussed will, to some extent, reflect the following regarding... Figure 4A The operation of the eyepiece waveguide under discussion is as follows: the diffraction of the input light originating from the second projector (not shown) by the ICG 425 causes the light to diffract into the plane of the waveguide and propagate within the plane of the waveguide, as indicated by rays 431 and 435. As will be described, the rays represented by ray 431 and ray 435 will result in the generation of a field of view comprising two parts, each associated with the rays initially propagating into the upper half and lower half of the eyepiece waveguide, respectively.

[0087] Ray 431, after diffracting from ICG 425, propagates to the upper left and is diffracted from the grating at the top of the waveguide, producing ray 432, which propagates to the lower left. Ray 432 propagates within the waveguide and is diffracted from the grating in the lower part of the waveguide, producing a coupling event 433. The coupled ray 434 is shown propagating upwards from the lower part of the waveguide toward the user, thereby producing a portion of the field of view associated with the lower part of the user's field of view.

[0088] Simultaneously, ray 435 propagates downward to the left near axis 401 and is diffracted by a grating in the lower part of the waveguide near axis 401, producing ray 436, which propagates upward to the left. Ray 436 propagates in the waveguide and is diffracted by a grating in the upper part of the waveguide near axis 401, producing coupling event 437. Coupling ray 438 is shown propagating downward towards the user from the upper part of the waveguide near axis 401, thereby creating the lower part of the field of view. As will be apparent to those skilled in the art, rays coupled at an intermediate angle and operable to propagate in the waveguide will fill the field of view. Reference Figure 4C The field of view 460 is generated by the rays shown by rays 431 and 435.

[0089] Figure 4C It is shown Figure 4A The simplified k-space diagram of the eyepiece waveguide operation is shown. (Reference) Figure 4C The combined field of view, which includes four fields of view, is formed by the overlap between fields of view 410 and 430 and fields of view 460 and 470. Fields of view 410 and 430 are generated by light incident from the first projector, and fields of view 460 and 470 are generated by light incident from the second projector.

[0090] like Figure 4C As shown, each of the individual fields of view has a spatial range of approximately 50° vertically and 40° horizontally. By combining four individual fields of view in a combined field of view, the overlap between these fields of view produces a combined field of view characterized by a larger extended field of view of approximately 80° x 100°. Therefore, using an embodiment of the present invention that utilizes two projectors and a grating characterized by an increased grating period in two dimensions, waveguide displays with increased or extended field of view are enabled.

[0091] refer to Figure 4C Embodiments of the present invention provide a display with a spliced ​​field of view, which is formed by splicing together multiple individual fields of view, with or without overlap between adjacent fields of view. As will be apparent to those skilled in the art, in this embodiment of an eyepiece waveguide manufactured in a polymer having a refractive index of 1.75, the ring defined by the circle at n = 1.0 and the circle at n = 1.75 corresponds to an angle within the waveguide. It will be understood that, in contrast to designs utilizing expensive and specialized materials (e.g., sapphire and lithium niobate), embodiments of the present invention provide eyepiece waveguides that can be manufactured in low-cost, low-weight, and robust low-refractive-index materials (such as polymers) while still providing a large field of view in combined field-of-view designs. Although some of the discussion herein relates to polymer materials, embodiments of the present invention are not limited to these materials, and the concepts discussed herein apply to materials having a refractive index greater than 1.75. In particular, the ring having a boundary at n = 1.75 is not intended to limit the scope of the invention. Many variations, modifications, and substitutions will be recognized by those skilled in the art.

[0092] Figure 4C The k-space diagram in the figure shows that Figure 4A and 4B The illustrated eyepiece waveguide design is characterized by an increasing grating period along axes 401 and 402, because the center of the field of view 410 is translated a distance along axes 401 and 402, a distance greater than the distances from the origin to position 419 and from the origin to position 409. Therefore, in Figure 4A and 4B As shown and by Figure 4C In the eyepiece waveguide design described by the k-space diagram, the translation in k-space corresponding to ICG diffraction is greater than the distance from the origin to the center of the loop within the waveguide angle. Specifically, the distance from position 407 to position 409 in k-space (measured along axis 401) is greater than the distance from the origin to position 409 in k-space (measured along axis 401) (i.e., an increase in the grating period along axis 401), and the distance from position 407 to position 419 in k-space (measured along axis 402) is greater than the distance from the origin to position 419 in k-space (measured along axis 402) (i.e., an increase in the grating period along axis 402).

[0093] Such as about Figure 3G To describe more fully and in Figure 4C As shown, the diffraction of light into and out of the eyepiece waveguide, as well as the propagation of light within the eyepiece waveguide, results in several different translations of the fields of view 410, 430, 460, and 470 in k-space. Figure 4A and Figure 4C As shown, light diffracted from the ICG 405 will shift fields of view 410 and 430 to the right of the ring of the waveguide angle. OPE diffraction events will shift these fields of view to the lower right and upper right portions of the ring of the waveguide angle, respectively. Light diffracted from the grating lines as an EPE event will shift these fields of view to the positions shown for fields of view 410 and 430 in the eye space region of the k-space diagram.

[0094] like Figure 4B and Figure 4C As shown, light diffracted from ICG 425 will shift fields of view 460 and 470 to the left of the ring of the waveguide angle. OPE diffraction events will shift these fields of view to the lower left and upper left portions of the ring of the waveguide angle, respectively. Light diffracted from the grating lines as EPE events will shift these fields of view to the positions shown for fields of view 460 and 470 in the eye space region of the k-space diagram.

[0095] like Figure 4CAs shown, the center of each field of view is offset from the origin of the k-space map. This vertical and horizontal offset is caused by the use of gratings with increasing periods in both directions, as discussed herein. Therefore, by using two projectors, one providing image light to the first ICG and the other to the second ICG, an extended field of view can be created by stitching together the individual fields of view, where the overlap between the individual fields of view is defined by grating features.

[0096] It should be noted that, regarding Figure 4A and 4B The provided description refers to the central ray associated with the center pixel of the projected image frame. Additionally, the above description... Figure 4A and 4B The method utilizes a form to analyze the light rays formed at the edges of image frames. These rays can be called peripheral rays. As will be apparent to those skilled in the art, the propagation in the k-space graph is inversely correlated with the propagation in the image space, where the propagation in the upper part of the k-space graph corresponds to the propagation in the lower part of the image space. Figures 4A to 4C As shown, light rays coupled upwards from the bottom of the eyepiece waveguide are guided into the eye box in a manner suitable for reaching the user's pupil when it is well centered relative to the eyepiece waveguide. Furthermore, light rays coupled downwards from the top of the eyepiece waveguide are guided into the eye box in a manner suitable for reaching the user's pupil when it is well centered relative to the eyepiece waveguide. Therefore, embodiments of the present invention provide an effective design in which light is coupled out in a manner preferably reaching the user's pupil when the pupil is well centered within the eye box.

[0097] By tracking the peripheral rays associated with the top, bottom, and sides of the field of view for each image frame, the inventors have demonstrated that rays corresponding to the bottom of the field of view are effectively coupled out at the bottom of the eyepiece waveguide, with reduced or minimal coupling out at the top of the eyepiece waveguide. Therefore, embodiments of the invention increase the light efficiency reaching the eyebox and pupil of the user's eye, because coupling events are increased and / or maximized for light from a projector supplying light to ICG 405 coupled out from the bottom of the eyepiece waveguide in an upward direction pointing towards the eyebox, and for light from a projector supplying light to ICG 425 coupled out from the top of the eyepiece waveguide in a downward direction pointing towards the eyebox.

[0098] Figure 4D This is a simplified flowchart illustrating a method for operating an eyepiece waveguide defined by a first region and a second region according to an embodiment of the present invention. Figure 4D The method shown can be used to... Figure 4A and 4BThis is implemented in the context of a multi-projector waveguide display with the illustrated eyepiece waveguide. Method 480 includes guiding light from a first projector to incident on a first coupling grating (ICG) (482). The first projector is shown as... Figure 6A The projector 621 in the middle can project incident light onto the surface shown as Figure 4A ICG 405 or Figure 6A The light on the first ICG of the ICG 620.

[0099] Light incident on the first ICG is diffracted into the plane of the eyepiece waveguide, and a portion of the light from the first projector is diffracted into a first portion of a first region of the eyepiece waveguide, into a first portion of a second region, into a second portion of the second region, and out of the eyepiece waveguide (484). Reference Figure 4A Light diffracted into the first part of the first region 403 of the eyepiece waveguide is transmitted to the first part of the second region 404 without diffraction, while... Figure 6A In this process, light diffracted into a first portion 602 of the first region 601 of the eyepiece waveguide is diffracted in the plane of the eyepiece waveguide toward a first portion 605 of the second region 604. Therefore, in some embodiments, the first portion of the first region of the eyepiece waveguide includes a first set of diffractive optical elements, such as a first set of gratings that are shimmered and characterized by reduced coupling efficiency of the light from the first projector.

[0100] As light propagates in the first portion of the second region of the eyepiece waveguide, diffraction from diffractive optical elements (such as gratings) causes the light to be reguided toward the second portion of the second region 404, such as... Figure 4A The light ray 412 is shown. The grating in the first part of the second region can be oriented at ~150° relative to the axis passing through ICG 405 and ICG 425. Furthermore, Figure 4A The light ray 412 shown propagates in the waveguide and is diffracted from the grating in the second portion of the second region, thus producing coupling out from the eyepiece waveguide. The grating in the second portion of the second region can be oriented at ~-150° relative to the axis passing through ICG 405 and ICG 425. (See also: ...) Figure 4A As described, the coupled light rays propagate upwards toward the user from a second portion of a second region of the waveguide, thereby producing a portion of the field of view associated with the lower part of the user's field of view.

[0101] Another portion of the light from the first projector is diffracted into a second portion of the first region of the eyepiece waveguide, into a second portion of the second region, into the first portion of the second region, and out of the eyepiece waveguide (486). Reference Figure 4ALight diffracted into the second portion of the first region 403 of the eyepiece waveguide is transmitted to the second portion of the second region 404 without diffraction, whereas in other embodiments, light diffracted into the second portion of the first region of the eyepiece waveguide diffracts in the plane of the eyepiece waveguide toward the second portion of the second region. Therefore, in some embodiments, the second portion of the first region of the eyepiece waveguide includes a second set of diffractive optical elements, such as a second set of gratings that is blazed and characterized by reduced coupling efficiency of the light from the first projector.

[0102] As light propagates in the second portion of the second region of the eyepiece waveguide, diffraction from diffractive optical elements (such as gratings) causes the light to be reguided toward the first portion of the second region 404, such as... Figure 4A The light ray 416 is shown. The grating in the first part of the first region can be oriented at ~30° relative to the axis passing through ICG 405 and ICG 425. Furthermore, Figure 4A The light ray 416 shown propagates in the waveguide and is diffracted from the grating in the first portion of the second region 404, thus coupling out from the eyepiece waveguide. The grating in the second portion of the first region can be oriented at approximately -30° relative to the axis passing through ICG 405 and ICG 425. (See also...) Figure 4A As described, the coupled light rays propagate downwards toward the user from a first portion of the second region of the waveguide, thereby creating a portion of the field of view associated with the upper part of the user's field of view.

[0103] The method also includes guiding light from the second projector to incident on a second coupling grating (ICG) (488). The second projector is shown as... Figure 6A The second projector 626 in the diagram can project incident light onto the surface shown as... Figure 4A ICG 425 or Figure 6A The light on the second ICG of ICG 625.

[0104] Light incident on the second ICG is diffracted into the plane of the eyepiece waveguide, and a portion of the light from the second projector is diffracted into a first portion of the second region of the eyepiece waveguide, into a first portion of the first region, into a second portion of the first region, and out of the eyepiece waveguide (490). Reference Figure 4B Light diffracted into the first portion of the second region 404 of the eyepiece waveguide is transmitted to the first portion of the first region 403 without diffraction, whereas in other embodiments, light diffracted into the first portion of the second region of the eyepiece waveguide diffracts in the plane of the eyepiece waveguide toward the first portion of the first region. Therefore, in some embodiments, the first portion of the second region of the eyepiece waveguide includes a third set of diffractive optical elements, such as a third set of gratings that is blazed and characterized by reduced coupling efficiency of the light from the second projector.

[0105] As light propagates in the first portion of the first region of the eyepiece waveguide, diffraction from diffractive optical elements (such as gratings) causes the light to be reguided towards the second portion of the first region, such as... Figure 4B The light ray 432 is shown. The grating in the first part of the first region can be oriented at ~30° relative to the axis passing through ICG 405 and ICG 425. Furthermore, Figure 4B The light ray 432 shown propagates in the waveguide and is diffracted from the grating in the second portion of the first region, thus producing coupling out from the eyepiece waveguide. The grating in the second portion of the first region can be oriented at approximately -30° relative to the axis passing through ICG 405 and ICG 425. (See also: ...) Figure 4B As described, the coupled light rays propagate upwards toward the user from the second portion of the first region of the waveguide, thereby producing a portion of the field of view associated with the lower part of the user's field of view.

[0106] Another portion of the light from the second projector is diffracted into a second portion of the second region of the eyepiece waveguide, into a second portion of the first region, into a first portion of the first region, and out of the eyepiece waveguide (492). Reference Figure 4B In some embodiments, light diffracted into a second portion of the second region of the eyepiece waveguide is transmitted to a second portion of the first region without diffraction. In other embodiments, light diffracted into a second portion of the second region of the eyepiece waveguide is diffracted in the plane of the eyepiece waveguide toward a second portion of the first region. Therefore, in some embodiments, the second portion of the second region of the eyepiece waveguide includes a fourth set of diffractive optical elements, such as a fourth set of gratings that is blazed and characterized by reduced coupling efficiency of the light from the second projector.

[0107] As light propagates in the second portion of the first region of the eyepiece waveguide, diffraction from diffractive optical elements (such as gratings) causes the light to be reguided toward the first portion of the first region, such as... Figure 4B The light ray 436 is shown. The grating in the second part of the first region can be oriented at ~-30° relative to the axis passing through ICG 405 and ICG 425. Furthermore, Figure 4B The light ray 436 shown propagates in the waveguide and is diffracted from the grating in the first portion of the first region, thus producing coupling out from the eyepiece waveguide. The grating in the first portion of the first region can be oriented at ~30° relative to the axis passing through ICG 405 and ICG 425. (See also: ...) Figure 4B As described, the coupled light rays propagate downwards toward the user from a first portion of a first region of the waveguide, thereby creating a portion of the field of view associated with the upper part of the user's field of view.

[0108] In some embodiments, light from the first projector is incident on the first ICG at a first non-zero angle of incidence, and light from the second projector is incident on the second ICG at a second non-zero angle of incidence equal to zero minus the first non-zero angle of incidence. In these embodiments, the first field of view of the first portion of the second region is centered at a non-zero angle of incidence, and the second field of view of the first portion of the first region is centered at a non-zero angle of incidence.

[0109] It should be understood that, according to embodiments of the present invention, Figure 4D The specific steps illustrated provide a particular method for operating the eyepiece waveguide defined by the first and second regions. Other sequences of steps can also be performed according to alternative embodiments. For example, alternative embodiments of the invention may perform the above steps in a different order. Furthermore, Figure 4D The individual steps shown may include multiple sub-steps, which can be executed in various orders suitable for the individual steps. Furthermore, additional steps may be added or removed depending on the specific application. Many variations, modifications, and substitutions will be recognized by those skilled in the art.

[0110] Figure 5A This is a simplified plan view illustrating a multi-projector waveguide display utilizing an eyepiece waveguide with a reduced grating period according to an embodiment of the present invention. Regarding Figures 4A to 4C The provided description applies to Figure 5A Up to 5C, but used for eyepiece waveguides with reduced grating period.

[0111] In this design, where the grating period is reduced by increasing the grating pitch, light couples out after traveling a reduced distance along the eyepiece waveguide. (Reference) Figure 5A Light incident on ICG 505 is coupled out in field of view 510 of the eyepiece waveguide adjacent to ICG 505. Similarly, light incident on ICG 525 is coupled out in field of view 530 of the eyepiece waveguide adjacent to ICG 525.

[0112] Figure 5B It is shown Figure 5A The simplified k-space diagram of the operation of the eyepiece waveguide is shown.

[0113] Figure 5B The k-space diagram in the figure shows that Figure 5AThe eyepiece waveguide design shown is characterized by a decreasing grating period along axis 501 and an increasing grating period along axis 502. The decreasing grating period along axis 501 is shown by translating the center of field of view 510 / 560 along axis 501 by a distance less than the distance from the origin to the center of the loop within the waveguide angle. Similarly, the center of field of view 530 / 570 is translated along axis 501 by a distance less than the distance from the origin to the center of the loop within the waveguide angle. In the vertical direction aligned with axis 502, the design is consistent with the above description. Figure 4C The behavior discussed is similar. Therefore, the center of field of view 510 / 560 is translated a certain distance along axis 502, which is greater than the distance from the origin to the center of the loop of the waveguide's inner angle. Similarly, the center of field of view 530 / 570 is translated a certain distance along axis 501, which is greater than the distance from the origin to the center of the loop of the waveguide's inner angle.

[0114] like Figure 5B As shown, using Figure 5A The illustrated eyepiece waveguide design achieves a field of view of approximately 180° along a first direction from ~50° to about 180°, with a maximum range of ~50° along a second direction orthogonal to the first direction. It should be noted that the combination of fields of view 510 and 560 in the upper part of the k-space diagram and fields of view 530 and 570 in the lower part of the k-space diagram results in a notch in region 575, which can be selectively masked for specific applications.

[0115] Figure 6A This is a simplified plan view illustrating the elements of a multi-projector waveguide display according to an embodiment of the present invention. Figure 6A As shown and as described more fully below, the eyepiece waveguide 600 (which may also be referred to as a waveguide display assembly) includes an ICG 620, which may be referred to as a first ICG. The ICG 620 is operable to receive input light from a first projector 621. (As per...) Figure 1 The ICG 620, as discussed, receives input light propagating along a direction having a component aligned with the z-axis (i.e., perpendicular to the input surface of the eyepiece waveguide 600 located in the xy plane) and couples at least a portion of the input light into the waveguide.

[0116] The eyepiece waveguide 600 also includes an ICG 625, which may be referred to as a second ICG. The ICG 625 is operable to receive input light from the second projector 626. (See also: ...) Figure 1 The ICG 620, as discussed, receives input light propagating along a direction having a component aligned with the z-axis (i.e., perpendicular to the input surface of the eyepiece waveguide 600 located in the xy plane) and couples at least a portion of the input light into the waveguide.

[0117] The ICG 620 and ICG 625 are positioned along the x-axis within the plane of the eyepiece waveguide. (Reference) Figure 6A The waveguide display 600 also includes multiple regions in which light diffracts within and out of the plane of the waveguide display. These multiple regions include a first region 601 and a second region 604. In each region, grating lines or other diffraction structures present in a portion of the region are oriented at a predetermined angle relative to other grating lines present in other portions of the region or relative to grating lines in other regions (or other regions among the multiple regions).

[0118] It should be noted that, Figure 6A and Figure 6B In the two projector designs shown, the grating in a portion of the region can perform different diffraction functions depending on the source of the light incident on the grating. As an example, when propagating in the second portion 606 of the second region 604, light incident on the ICG 620 can interact with the grating in the second portion 606 to couple out from the eyepiece waveguide. That is, the grating in the second portion 606 can be used as an EPE grating for light from the projector 621. Conversely, when propagating in the second portion 606 of the second region 604, light incident on the ICG 625 can interact with the grating in the second portion 606 to diffract towards the first portion 605 in the plane of the eyepiece waveguide. That is, the grating in the second portion 606 can be used as an OPE grating for light from the second projector 626. Similar different effects will be apparent for other gratings in other portions, resulting in different functions (i.e., OPE or EPE functions) depending on the source of light propagating in the eyepiece waveguide. Many variations, modifications, and substitutions will be recognized by those skilled in the art.

[0119] Compared to the region 606, which has only a single set of gratings, the overlapping region 630 between the first region 601 and the second region 604 will produce multiple effects, such as EPE and OPE effects. Due to the presence of multiple sets of gratings, diffraction effects will occur for light incident from both projectors.

[0120] The actual implementation of providing gratings in the first portion 602 and second portion 603 of the first region 601 and the first portion 605 and second portion 606 of the second region 604 can vary. As an example, the gratings (i.e., gratings oriented at -30° to the x-axis) in the second portion 603 of the first region 601 and the first portion 605 of the second region 604 can be formed on a first surface of the substrate used to manufacture the eyepiece waveguide, and the gratings (i.e., gratings oriented at 30° to the x-axis) in the first portion 602 of the first region 601 and the second portion 606 of the second region 604 can be formed on a second surface of the substrate opposite to the first surface. Therefore, the overlapping region 630 can be formed by gratings present on both surfaces of the eyepiece waveguide.

[0121] Figure 6B This is a simplified plan view illustrating the propagation of light in a multi-projector waveguide display according to an embodiment of the present invention.

[0122] refer to Figure 6A and 6B The first region 601 includes a first portion 602, also referred to as the upper or top portion, characterized by a gate line 616 oriented at an angle of approximately 30° to the x-axis along which the ICGs 620 and 625 are positioned. The first region 601 also includes a second portion 603, also referred to as the lower or bottom portion, characterized by a gate line 618 oriented at an angle of approximately -30° to the x-axis. Thus, gate lines 616 and 618 are oriented at an angle of approximately 60° to each other. As will be apparent to those skilled in the art, for clarity, the spacing between gate lines 616 and 618 is not drawn to scale.

[0123] The second region 604 includes a first portion 605, also referred to as the upper or top portion, characterized by a grid line 629 oriented at an angle of approximately 120° to the x-axis. The second region 604 also includes a second portion 606, also referred to as the lower or bottom portion, characterized by a grid line 628 oriented at an angle of approximately -120° to the x-axis. Thus, and in a manner similar to the first region 601, the grid lines 629 and 628 in the second region 604 are oriented at an angle of approximately 60° to each other. As will be apparent to those skilled in the art, for clarity, the spacing between the grid lines 629 and 628 is not drawn to scale.

[0124] In the overlapping region 630, grating line 616 overlaps with grating line 629, and grating line 618 overlaps with grating line 638. Therefore, in addition to the portion including a single set of grating lines, the overlapping region 630 also includes multiple sets of overlapping grating lines and can be referred to as an intersecting region. This overlapping region allows designers to achieve designs with larger exit pupils and balances the operational efficiency of the eyepiece waveguide as the exit pupil size increases, making it more tolerant of user pupil movements.

[0125] Although the gate line 616 in the first portion 602 of the first region 601 and the gate line 618 in the second portion 603 of the first region 601 are shown to intersect at the x-axis, wherein the gate line 616 in the second portion 603 does not overlap with the gate line 618 in the first portion 602, this is not required by embodiments of the invention. In some embodiments, the gate line 616 extends into the second portion 603, and the gate line 618 extends into the first portion 602.

[0126] As described more fully herein, the presence of gratings in different portions of the first region 601 and the second region 604, including the overlap of gratings in the overlapping region 630, enables the gratings to function as orthogonal pupil expanders (OPEs) to diffract light propagating in the plane of the eyepiece waveguide into a new propagation direction and to expand the lateral dimension of light propagating in the eyepiece waveguide; and as exiting pupil expanders (EPEs) to diffract light propagating in the plane of the eyepiece waveguide beyond the plane of the eyepiece waveguide. It is particularly noteworthy that a set of gratings can function as either an OPE or an EPE, depending on the direction of light propagation in the eyepiece waveguide. As an example, for a given set of gratings, light propagating in a first direction can be diffracted in the plane of the eyepiece waveguide (OPE function), while light propagating in a second direction orthogonal to the first direction can be diffracted beyond the plane of the eyepiece waveguide (EPE function).

[0127] refer to Figure 6A and 6B When light propagates through the first portion 602 of the first region 601, its interaction with the grating lines 616 results in diffraction in the plane of the eyepiece waveguide along the axis between the ICGs. As a result of this diffraction, similar to OPE diffraction, multiple copies of the first copy of the image are formed and propagate in a direction aligned with this axis.

[0128] Light propagating from the first section 602 to the overlapping region 630 undergoes diffraction in multiple directions both within and outside the eyepiece waveguide plane due to the presence of grating lines oriented at approximately 30° to the x-axis and at approximately 120° to the x-axis. Light propagating in the x-axis aligned direction will encounter grating line 629 and will diffract in the eyepiece waveguide plane along the direction indicated by arrow 627. As light propagates along this direction, it will encounter grating line 628 and experience a coupling event from the eyepiece waveguide. These coupling events occur in… Figure 6B It is shown in the middle by an open circle.

[0129] Referring to section 605, light propagating in a direction aligned with the x-axis passes through overlapping region 630, encounters grating line 629, and diffracts in the plane of the eyepiece waveguide along the direction of arrow 627. During these diffraction events, a staircase progression of light will occur as appropriate for the OPE function. As the light propagates further along the direction of arrow 627, it enters section 606, encounters grating line 628, and undergoes additional coupling events from the eyepiece waveguide. These coupling events, like those generated in overlapping region 630, in... Figure 6B It is shown in the middle by an open circle.

[0130] Therefore, the light entering the eyepiece waveguide at ICG 620 and generated by the first projector 621 can be coupled out in the second region 604. Figure 6A and 6B In the design shown, light coupled into the eyepiece waveguide at ICG 620 preferably passes through the first region 601 without experiencing an out-of-line event, resulting in almost no light loss through out-of-line, where passing through the first region 601 only causes diffraction in the plane of the eyepiece waveguide, replicating the OPE function. Therefore, all out-of-line events of light from the first projector are preferably experienced in the second region 604, which provides the output of one of the sub-displays forming a combined display. Because, as Figure 2B As shown, the light cone entering the ICG is centered at an illegal incident angle, and the light cone coupled out in the second region 604 also propagates at an illegal incident angle, enabling spatial separation between sub-displays and splicing of combined displays.

[0131] In addition to the light entering ICG 620, the light entering ICG 605 will undergo similar interactions as it propagates through the second region 604, resulting in OPE interactions, and in the first region 601, it will undergo EPE interactions. Many variations, modifications, and substitutions will be recognized by those skilled in the art.

[0132] Figure 7A This is a simplified plan view illustrating a six-projector waveguide display according to an embodiment of the present invention. Figure 7A In the six-projector design shown, the six projectors are arranged at a 60° angle around the periphery of the eyepiece waveguide. Figure 7A The six-projector waveguide display shown is designed using a reduced grating period.

[0133] Light from six projectors (not shown) is coupled into a shared eyepiece waveguide region via ICG 710, 713, 714, 716, 718 and 720. The shared eyepiece waveguide region includes three distinct grating vectors: grating vector 722, which is aligned with the axis (i.e., vertical orientation axis 702) passing through the perpendicular bisectors of the lines connecting ICGs 713 and 714 and the perpendicular bisectors of the lines connecting ICGs 718 and 720; grating vector 724, which is aligned with the axis (i.e., the axis oriented at -30° to vertical axis 702) passing through the perpendicular bisectors of the lines connecting ICGs 710 and 720 and the perpendicular bisectors of the lines connecting ICGs 714 and 716; and grating vector 726, which is aligned with the axis (i.e., the axis oriented at +30° to vertical axis 702) passing through the perpendicular bisectors of the lines connecting ICGs 716 and 718 and the perpendicular bisectors of the lines connecting ICGs 710 and 713.

[0134] Referring to ICG 710, light coupled via ICG 710 propagates in regions 712 and 719 along a direction having a component aligned with axis 701. Regions 712 and 719 utilize a similar... Figure 5A The design shown is a herringbone pattern, where the grating in region 712 is tilted at an angle of -120° to the horizontal axis 701, and the grating in region 719 is tilted at an angle of 120° to the horizontal axis 701. Light associated with the bottom of the field of view propagates through region 719, undergoes diffraction towards region 712 (e.g., almost no coupling out), and couples out from region 712. Similarly, light associated with the top of the field of view propagates through region 712, undergoes diffraction towards region 719 (e.g., almost no coupling out), and couples out from region 719. Regarding... Figure 7B Additional descriptions related to these interactions are provided.

[0135] use Figure 7A The six-projector design shown includes six coupling gratings and a shared eyepiece waveguide region, achieving a combined conical field of view of ~100° in a polymer eyepiece with a refractive index of ~1.75.

[0136] Figure 7B It is shown Figure 7A A simplified plan view of a single projector element of a six-projector waveguide display is shown. Figure 7C It is shown Figure 7B A simplified k-space diagram of the operation of a single projector element is shown. (Reference) Figure 7B and 7C This can describe light diffraction and the accompanying field-of-view translation in k-space. For example... Figure 7BAs shown, when light propagates into region 712, a portion of the light diffracted from ICG 710 can be represented by ray 740. The diffraction from the grating in region 712 will result in the generation of ray 741 in the upper half of the guide waveguide (i.e., region 719). This can be considered an OPE event.

[0137] After propagating into the upper half of the waveguide (i.e., region 719), the diffraction from the grating in region 719 will result in the generation of an output ray 742 propagating downward toward the user, representing the light in the upper part of the user's field of view.

[0138] Similarly, when ray 750 propagates from the ICG 710 into the upper half of the waveguide (i.e., region 719), it will generate light in the lower part of the user's field of view. Diffraction from the grating to the upper half of the waveguide (i.e., region 719) will result in the generation of ray 751 (OPE event), which propagates to the lower half of the waveguide, i.e., region 712. Diffraction in region 712 as an EPE event will result in the generation of output ray 752 propagating upwards towards the user.

[0139] It should be noted that, although Figure 7A and 7B The shared eyepiece waveguide region shown only includes the overlap between adjacent grating vectors in the central region of the grating overlap. In other embodiments, the overlapping region may extend closer to each of the respective ICGs. These designs with increased overlap enable performance where the visibility of the field of view is more tolerant of deviations in the user's pupil position that may be caused by changes in the user's gaze, such as the pupil moving away from the center of the eyebox.

[0140] refer to Figure 7C The diffraction from ICG 710 corresponds to a translation of the field of view from 730 to position 732. The diffraction (OPE event) from the grating in region 719, represented by ray 751, causes the field of view to be translated to position 734, and the diffraction (EPE event) in region 712 causes the field of view to be translated to the eye space region of the k-space map.

[0141] Similarly, the diffraction (OPE event) from the grating in region 712, represented by ray 741, causes the field of view to shift to position 736, and the diffraction (EPE event) in region 719 causes the field of view to shift to the eye space region of the k-space map.

[0142] Figure 7C The k-space diagram in the figure shows that Figure 7B The eyepiece waveguide design shown utilizes a grating with a reduced grating period along axis 701, because the center of field of view 730 is translated a certain distance along axis 701, which is less than the distance from the origin to the loop of the waveguide's inner angle.

[0143] Figure 7D It is shown Figure 7A The simplified k-space diagram of the operation of the six-projector waveguide display is shown. When... Figure 7B The analysis performed on a portion of the six-projector waveguide display shown is extended to five other projectors, as... Figure 7D As shown, a combined field of view comprising six partially overlapping fields of view is generated. This combined field of view is formed by stitching together individual fields of view, which are typically conical sectors with circular ends, resulting in a circular combined field of view, characterized by a ~100° combined conical field of view in a polymer eyepiece with a refractive index of ~1.75.

[0144] Figure 8 This is a simplified perspective view illustrating the integration of eyeglasses and one or more eyepiece waveguides according to an embodiment of the present invention. Figure 8 As shown, the eyepiece waveguide can be integrated into the right frame 801 and left frame 802 of a pair of glasses. Due to the functionality of the eyepiece waveguide described herein, the integration of the first eyepiece waveguide 830 in the right frame 801 and the second eyepiece waveguide 840 in the left frame 802 enables a wide field of view. Figure 8 As shown, the first waveguide display 805 utilizes two eyepiece waveguides 830 and 840, each eyepiece waveguide including ICG 832 / 842 and CPE 834 / 844.

[0145] It should also be understood that the examples and embodiments described herein are for illustrative purposes only, and various modifications or changes made thereto are implied to those skilled in the art and will be included within the spirit and scope of this application and the scope of the claims.

Claims

1. An eyepiece waveguide for an augmented reality display system, the eyepiece waveguide comprising: A substrate having a first surface and a second surface; A diffraction input coupling element is formed on or in the first or second surface of the substrate, the diffraction input coupling element being configured to receive an input beam and couple the input beam into the substrate as a guide beam; as well as A diffractive combined pupil expander-extractor (CPE) element is formed on or within the first or second surface of the substrate, wherein the diffractive CPE element includes a first portion and a second portion divided by an axis passing through the diffractive input coupling element, and an overlapping region, wherein: A first set of diffractive optical elements is disposed in the first portion and extends partially into the overlapping region, wherein all diffractive optical elements in the first set of diffractive optical elements are oriented at a positive angle relative to the axis. A second set of diffractive optical elements is disposed in the second portion and extends partially into the overlapping region, wherein all diffractive optical elements in the second set are oriented at a negative angle relative to the axis; and The overlapping region is centered on the axis.

2. The eyepiece waveguide according to claim 1, wherein, The positive angle is approximately 30°, and the negative angle is approximately -30°.

3. The eyepiece waveguide according to claim 1, wherein, The first set of diffractive optical elements includes a first set of diffraction gratings, and the second set of diffractive optical elements includes a second set of diffraction gratings.

4. The eyepiece waveguide according to claim 1, wherein, The input beam is incident on the diffraction input coupling element at a non-zero incident angle.

5. The eyepiece waveguide according to claim 4, wherein, The diffraction input coupling element includes a grating with a grating period, and wherein the light cone coupled by the diffraction input coupling element is centered on an axis parallel to the substrate.

6. An eyepiece waveguide for an augmented reality display system, the eyepiece waveguide comprising: A substrate having a first surface and a second surface; A first diffraction input coupling element is formed on the first surface or the second surface of the substrate or in the first surface or the second surface of the substrate, and the first diffraction input coupling element is configured to receive a first input beam and couple the first input beam into the substrate as a first guide beam. A second diffraction input coupling element is formed on the first surface or the second surface of the substrate or in the first surface or the second surface of the substrate. The second diffraction input coupling element is configured to receive a second input beam and couple the second input beam into the substrate as a second guiding beam. A diffractive combined pupil expander-extractor (CPE) element is formed on the first surface or the second surface of the substrate, or in the first surface or the second surface of the substrate, wherein the diffractive CPE element is positioned as follows: Receive the first guide beam from the first diffraction input coupling element; Receive the second guide beam from the second diffraction input coupling element; At least a portion of the first guide beam is coupled out within a first angular range to form a first field of view of the combined field of view; as well as At least a portion of the second guide beam is coupled out within a second angular range to form a second field of view of the combined field of view; The diffractive CPE element includes a first portion and a second portion divided by an axis passing through the diffractive input coupling element, and an overlapping region, wherein: A first set of diffractive optical elements is disposed in the first portion and extends partially into the overlapping region, wherein all diffractive optical elements in the first set of diffractive optical elements are oriented at a positive angle relative to the axis. A second set of diffractive optical elements is disposed in the second portion and extends partially into the overlapping region, wherein all diffractive optical elements in the second set are oriented at a negative angle relative to the axis; and The overlapping region is centered on the axis.

7. The eyepiece waveguide according to claim 6, wherein, The diffractive CPE element includes: a first set of gratings disposed in a first portion of a first region oriented at approximately 30° to the axis; and a second set of gratings disposed in a second portion of the first region oriented at approximately -30° to the axis.

8. The eyepiece waveguide according to claim 7, wherein, The diffractive CPE element includes: a third set of gratings disposed in a first portion of a second region oriented at approximately 150° to the axis; and a fourth set of gratings disposed in a second portion of the second region oriented at approximately -150° to the axis.

9. The eyepiece waveguide according to claim 6, wherein, The first input beam is incident on the substrate at an illegal line incident angle, and the first field of view of the combined field of view is centered on the illegal line incident angle.

10. The eyepiece waveguide according to claim 9, wherein, The second input beam is incident on the substrate at an angle of incidence of zero minus the illegal line, and the second field of view of the combined field of view is centered at an angle of incidence of zero minus the illegal line.

11. The eyepiece waveguide according to claim 6, wherein, The first field of view and the second field of view are stitched together.

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