Method and system for a waveguide projector with a wide field of view

Abstract

To provide a favorable method and system for a waveguide projector with a wide field of view.SOLUTION: A waveguide display disposed in glasses includes a first pupil expander assembly operable to project a first image defined by a first field of view, and a second pupil expander assembly that is disposed adjacently to the first pupil expander assembly and operable to project a second image defined by a second field of view different from the first field of view.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 62 / 474,493, filed March 21, 2017, and entitled "Method and System for Waveguide Projector with Wide Field of View," the disclosure of which is incorporated herein by reference in its entirety for all purposes. [Background technology]

[0002] Modern computing and display technology has 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 a viewer in a manner that appears or can be perceived as real. Virtual reality, or "VR," scenarios typically involve the presentation of digital or virtual image information without transparency to other actual, real-world visual input, while augmented reality, or "AR," scenarios typically involve the presentation of digital or virtual image information as an augmentation to the viewer's visualization of the real world around them.

[0003] Despite the advances made in these display technologies, there remains a need in the art for improved methods and systems relating to augmented reality systems, and particularly display systems. Summary of the Invention [Means for solving the problem]

[0004] The present invention relates generally to methods and systems relating to projection display systems, including wearable displays. More specifically, embodiments of the present invention provide methods and systems having an extended field of view compared to conventional systems. The present invention is applicable to a variety of applications in computer vision and image display systems.

[0005] According to an embodiment of the present invention, a waveguide display disposed within eyeglasses is provided. The waveguide display includes a first pupil expander assembly operable to project a first image defined by a first field of view. The waveguide display also includes a second pupil expander assembly disposed adjacent to the first pupil expander assembly and operable to project a second image defined by a second field of view different from the first field of view. The field of view and the second field of view can be tiled, or a portion of the first field of view can overlap a portion of the second field of view.

[0006] In one embodiment, the first pupil expander assembly and the second pupil expander assembly are disposed within a right lens frame of a pair of eyeglasses. The right lens frame has a nasal region, a peripheral region, and a center disposed between the nasal region and the peripheral region. The first field of view is centered at a position between the center and the nasal region. The second field of view is centered at a position between the center and the peripheral region. Furthermore, the waveguide display may also include a third pupil expander assembly operable to project a first image defined by the third field of view, and a fourth pupil expander assembly disposed adjacent to the third pupil expander assembly and operable to project a second image defined by a fourth field of view different from the third field of view. In this case, the third pupil expander assembly and the fourth pupil expander assembly may be disposed within a left lens frame of the pair of eyeglasses.

[0007] According to another embodiment of the present invention, a waveguide display disposed within eyeglasses is provided. The waveguide display includes a first diffractive input waveguide operable to receive input data from a first projector and a second diffractive input waveguide operable to receive input data from a second projector. The waveguide display also includes a diffractive output waveguide optically coupled to the first and second diffractive input waveguides and having a central normal. The diffractive output waveguide is operable to direct image data associated with the first projector toward a first field of view displaced relative to the central normal and to direct image data associated with the second projector toward a second field of view displaced relative to the central normal.

[0008] According to a specific embodiment of the present invention, there is provided a waveguide display disposed within eyeglasses. The waveguide display includes a first diffractive input waveguide operable to receive input data from a first projector and a second diffractive input waveguide operable to receive input data from a second projector. The waveguide display also includes a diffractive output waveguide optically coupled to the first and second diffractive input waveguides. The diffractive output waveguide is operable to form a first image beam having a first wavefront characterized by a first refractive power and to form a second image beam having a second wavefront characterized by a second refractive power different from the first refractive power.

[0009] In some embodiments, the waveguide display further includes a wavefront conditioning lens integrated with the waveguide display and a corrective lens integrated with the waveguide display. The wavefront conditioning lens can be a negative lens and the corrective lens can be a positive lens. As an example, the waveguide display can be characterized by a world side and a user side, the first image beam and the second image beam can be directed toward the user side, the wavefront conditioning lens can be disposed on the user side, and the corrective lens can be disposed on the world side.

[0010] Numerous advantages are achieved by the methods of the present invention over conventional techniques. For example, embodiments of the present invention provide methods and systems that can be used to increase the field of view of a display and improve the user experience. In certain embodiments, multiple depth planes are produced by the display, resulting in the generation of stereoscopic images. These and other embodiments of the present invention, along with many of their advantages and features, are described in more detail in the following text and in conjunction with the accompanying figures. The present invention provides, for example, the following. (Item 1) 1. A waveguide display disposed within a pair of eyeglasses, the waveguide display comprising: a first pupil expander assembly operable to project a first image defined by a first field of view; a second pupil expander assembly disposed adjacent to the first pupil expander assembly and operable to project a second image defined by a second field of view different from the first field of view; A waveguide display comprising: (Item 2) Item 1. A waveguide display as described in item 1, wherein the first pupil expander assembly and the second pupil expander assembly are disposed within a right lens frame of the eyeglasses. (Item 3) 3. The waveguide display of item 2, wherein the right lens frame has a nasal region, a peripheral region, and a center positioned between the nasal region and the peripheral region, and the first field of view is centered at a position between the center and the nasal region. (Item 4) Item 4. The waveguide display of item 3, wherein the second field of view is centered at a position between the center and the peripheral region. (Item 5) Item 1. The waveguide display of item 1, wherein the first field of view and the second field of view are tiled. (Item 6) Item 1. The waveguide display of item 1, wherein a portion of the first field of view overlaps with a portion of the second field of view. (Item 7) the first pupil expander assembly an input coupling element operable to receive image data from the first projector; an orthogonal pupil expander optically coupled to the input coupling element; an exit pupil expander optically coupled to the orthogonal pupil expander; Item 2. The waveguide display of item 1, comprising: (Item 8) 8. The waveguide display of item 7, wherein the first pupil expander assembly is characterized by an emission plane, and the exit pupil expander is operable to emit light at a non-zero angle relative to the emission plane. (Item 9) 1. A waveguide display disposed within a pair of eyeglasses, the waveguide display comprising: a first diffractive input waveguide operable to receive input data from a first projector; a second diffractive input waveguide operable to receive input data from a second projector; a diffractive output waveguide optically coupled to the first diffractive input waveguide and the second diffractive input waveguide, the diffractive output waveguide having a central normal, the diffractive output waveguide comprising: directing image data associated with a first projector toward a first field of view displaced relative to the central normal; directing image data associated with a second projector toward a second field of view displaced relative to the central normal; a diffractive output waveguide operable to A waveguide display comprising: (Item 10) 10. The waveguide display of claim 9, wherein the first field of view and the second field of view are tiled and the central normal passes through the boundaries of each of the first field of view and the second field of view. (Item 11) the image data associated with the first projector has a first wavefront characterized by a first refractive power; the image data associated with the second projector has a second wavefront characterized by a second refractive power different from the first refractive power. Item 10. The waveguide display of item 9. (Item 12) 10. The waveguide display of item 9, further comprising a first input coupling element optically coupled to the first diffractive input waveguide and a second input coupling element optically coupled to the second diffractive input waveguide. (Item 13) Item 13. A waveguide display as described in item 12, wherein the first input coupling element, the first diffractive input waveguide, the second input coupling element, the second diffractive input waveguide, and the diffractive output waveguide are in the same plane. (Item 14) 10. The waveguide display of claim 9, wherein the first diffraction input waveguide is positioned on a first side of the diffraction output waveguide and the second diffraction input waveguide is positioned on an opposite side of the diffraction output waveguide. (Item 15) 1. A waveguide display disposed within a pair of eyeglasses, the waveguide display comprising: a first diffractive input waveguide operable to receive input data from a first projector; a second diffractive input waveguide operable to receive input data from a second projector; a diffractive output waveguide optically coupled to the first diffractive input waveguide and the second diffractive input waveguide, the diffractive output waveguide comprising: forming a first image beam having a first wavefront characterized by a first refractive power; forming a second image beam having a second wavefront characterized by a second refractive power different from the first refractive power; a diffractive output waveguide operable to A waveguide display comprising: (Item 16) Item 16. The waveguide display of item 15, wherein the first refractive power is positive and the second refractive power is negative. (Item 17) the diffractive output waveguide is characterized by an emission plane; the first image beam has a diverging wavefront and a central ray normal to the emission plane; the second image beam has a converging wavefront and a central ray normal to the emission plane. Item 17. A waveguide display according to item 16. (Item 18) Item 16. The waveguide display of item 15, wherein the first image beam and the second image beam are collinear. (Item 19) Item 16. The waveguide display of item 15, further comprising a first input coupling element optically coupled to the first diffractive input waveguide and a second input coupling element optically coupled to the second diffractive input waveguide. (Item 20) 20. The waveguide display of item 19, wherein the first input coupling element, the first diffractive input waveguide, the second input coupling element, the second diffractive input waveguide, and the diffractive output waveguide are in the same plane. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 diagrammatically illustrates the light path of a viewing optical assembly (VOA) that may be used to present a digital or virtual image to a viewer, according to an embodiment of the present invention.

[0012] [Figure 2] FIG. 2 is a simplified perspective view illustrating glasses including a waveguide display optically coupled to two projectors, according to one embodiment of the present invention.

[0013] [Figure 3] FIG. 3 is a simplified schematic diagram illustrating binocular field overlap, according to one embodiment of the present invention.

[0014] [Figure 4A]FIG. 4A is a simplified perspective view illustrating a waveguide display producing an extended field of view, according to one embodiment of the present invention.

[0015] [Figure 4B] FIG. 4B is a simplified exploded perspective view illustrating a waveguide display with overlapping elements, according to one embodiment of the present invention.

[0016] [Figure 5A] FIG. 5A is a simplified perspective view illustrating a waveguide display producing multiple depth planes, according to one embodiment of the present invention.

[0017] [Figure 5B] FIG. 5B is a simplified side view illustrating the integration of a lens with the waveguide display shown in FIG. 5A.

[0018] [Figure 6] FIG. 6 is a simplified schematic plan view illustrating a waveguide display producing a tiled field of view, according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention relates generally to methods and systems relating to projection display systems, including wearable displays. More specifically, embodiments of the present invention provide methods and systems having an extended field of view compared to conventional systems. The present invention is applicable to a variety of applications in computer vision and image display systems, including stereoscopic systems, and light field projection systems, systems that deliver beamlets of light to a user's retina, or the like.

[0020] Embodiments of the present invention typically utilize a pupil expander assembly including an exit pupil expander (EPE) that defines the field of view of the pupil expander assembly. While increasing the lateral dimensions of the EPE can increase the field of view, other optical elements within the pupil expander assembly, including an orthogonal pupil expander (OPE), typically constrain the amount of light that can be delivered to the EPE. For example, increasing the size of the EPE by 10% may not result in a 10% increase in the field of view, for example, because the OPE may already be delivering light to the EPE in an efficient manner. In other words, if the OPE is optimized for light delivery, increasing the size of the EPE may not result in a corresponding increase in the field of view. As an example, with respect to a waveguide structure, total internal reflection (TIR) ​​limits the angles at which light can be injected into the waveguide, preventing an increase in the EPE size from producing a corresponding increase in the field of view. Additionally, for example, selecting a material with a higher refractive index can improve the angular range over which the injected light can be utilized, but cost, weight, and other factors impose practical limits on material choice.

[0021] Thus, some embodiments of the present invention utilize multiple OPEs to deliver light to a common EPE, thereby increasing the field of view provided by the common EPE. As a result, some embodiments of the present invention provide a unique solution because they achieve an increase in the field of view of the EPE through the use of multiple OPEs coupled to the EPE, rather than as a result of an increase in the size of the EPE. Other embodiments utilize multiple EPEs to increase the field of view provided to a user. As described herein, the use of multiple OPEs provides an opportunity to increase the size of the EPE, which can result in an additional increase in field of view.

[0022] FIG. 1 diagrammatically illustrates light paths within a viewing optical assembly (VOA) that may be used to present a digital or virtual image to a viewer, according to one embodiment of the present invention. The VOA includes a projector 101 and an eyepiece 100 that may be worn around the viewer's eye. In some embodiments, projector 101 may include a group of red LEDs, a group of green LEDs, and a group of blue LEDs. For example, projector 101 may include two red LEDs, two green LEDs, and two blue LEDs, according to one embodiment. Eyepiece 100 may include one or more eyepiece layers. In one embodiment, eyepiece 100 includes three eyepiece layers, one for each of the three primary colors: red, green, and blue. In another embodiment, the eyepiece 100 may include six eyepiece layers: one set of eyepiece layers for each of the three primary colors configured to form a virtual image at one depth plane, and another set of eyepiece layers for each of the three primary colors configured to form a virtual image at another depth plane. In other embodiments, the eyepiece 100 may include three or more eyepiece layers for each of the three primary colors for three or more different depth planes. Each eyepiece layer may comprise a planar waveguide and include an internal coupling grating 107, an orthogonal pupil expander (OPE) region 108, and an exit pupil expander (EPE) region 109.

[0023] Still referring to FIG. 1 , the projector 101 projects image light onto an internal coupling grating 107 in the eyepiece lens layer 100. The internal coupling grating 107 couples the image light from the projector 101 into a planar waveguide, where it propagates toward the OPE region 108. The waveguide propagates the image light horizontally by total internal reflection (TIR). The OPE region 108 of the eyepiece lens layer 100 also includes a diffractive element that amplifies the image light from the internal coupling grating propagating in the waveguide and redirects it toward the EPE region 109. In other words, the OPE amplifies beamlets delivered to different portions of the EPE in orthogonal directions. The EPE region 109 includes a diffractive element that outcouples a portion of the image light propagating in the waveguide and directs it toward the viewer's eye 102 in a direction generally perpendicular to the plane of the eyepiece lens layer 100. In this method, an image projected by a projector 101 can be viewed by the viewer's eye 102.

[0024] As explained above, the image light generated by the projector may include light of three primary colors: blue (B), green (G), and red (R). Such image light is separated into its constituent colors so that the image light within each constituent color can be coupled into a separate waveguide within the eyepiece.

[0025] 2 is a simplified perspective view illustrating eyeglasses including a waveguide display optically coupled to two projectors, according to one embodiment of the present invention. As discussed herein, the total field of view of the system can be increased through the use of multiple projectors, e.g., multiple fiber scanning projectors, to drive a waveguide display associated with each eye of the user. The first waveguide display 205 utilizes two pupil expander assemblies, which can include an input coupling grating, an orthogonal pupil expander, and an exit pupil expander: a first right pupil expander assembly 210 and a second right pupil expander assembly 230. The second waveguide display 207 utilizes two additional pupil expander assemblies: a first left pupil expander assembly 220 and a second left pupil expander assembly 240.

[0026] As illustrated by the eyeglasses shown from a front perspective view in FIG. 2 , the right lens frame 201 of the eyeglasses includes a first right pupil expander assembly 210, which includes an input coupling element 212, which may be implemented as an input coupling grating (ICG). For clarity, the input coupling element 212 will be referred to herein as an ICG, although other diffractive structures can also be utilized by embodiments of the present invention. The pupil expander assembly 210 in the right lens frame 201 of the eyeglasses also includes an orthogonal pupil expander (OPE) 214 and an exit pupil expander (EPE) 216. In the design illustrated in FIG. 2 , light from a projector (not shown) impinges on the ICG 212 at the lower rim of the right lens frame 201, but this is not required by the present invention, and other input locations can also be utilized. Light coupled into the first pupil expander assembly 210 at the ICG 212 propagates through the OPE 214 and is coupled into the EPE 216. After propagating towards the nose region of the lens frame, the light is output from the EPE 216 towards the viewer's or user's right eye, as described more fully below.

[0027] In contrast to some pupil expander assemblies in which the output from the EPE is normal incident to the plane of the pupil expander assembly, the EPE 216 is designed so that output light exits the EPE 216 at a non-normal angle. As an example, light may exit the EPE 216 at a 15° angle to the normal, such that the light exits the EPE 216 in a direction traveling from the nose region toward the center of the lens frame 201. Thus, the EPE 216 directs light from the nose region of the lens frame toward the user's right eye, creating a left field of view, e.g., a 30° x 40° (lateral x vertical) field of view on the left side of the user's field of view.

[0028] The left lens frame 202 of the eyeglasses also includes a first left pupil expander assembly 220, which includes an input coupling element 222, which may be implemented as an input coupling grating (ICG). For purposes of clarity, the input coupling element 222 will be referred to herein as an ICG, although other diffractive structures can also be utilized by embodiments of the present invention. The first left pupil expander assembly 220 in the left lens frame 202 of the eyeglasses also includes an orthogonal pupil expander (OPE) 224 and an exit pupil expander (EPE) 226. In the design illustrated in FIG. 2 , light from a second projector (not shown) impinges on the ICG 222 at the lower rim of the right lens frame 202, but this is not required by the present invention, and other input locations can also be utilized. Light coupled into the first left pupil expander assembly 220 at the ICG 222 propagates through the OPE 224 and is coupled into the EPE 226. After propagating towards the nose region of the lens frame, the light is output from the EPE 226 towards the left eye of the viewer or user.

[0029] In a manner similar to the first right pupil expander assembly 210, but in a mirror image configuration, the EPE 226 is designed so that output light exits the EPE 226 at a non-normal angle, e.g., a 15° angle relative to the normal. Thus, light exits the EPE 226 in a direction moving from the nose region toward the center of the lens frame 202. As an example, control of the angle of emission can be achieved by varying the grating periodicity or pitch. Thus, the EPE 226 will direct light from the nose region of the lens frame toward the user's left eye, creating a right field of view, e.g., a 30° x 40° (lateral x vertical) field of view on the right side of the user's field of view.

[0030] An additional set of pupil expander assemblies is provided in the lens frames, as illustrated in FIG. 2. In the right lens frame 201, the second right pupil expander assembly 230 includes an ICG 232, an OPE 234, and an EPE 236. Light from a third projector (shown here) impinges on the ICG 232 at the lower rim of the right lens frame 201, although this is not required by the present invention and other input locations can be utilized. Light coupled into the second right pupil expander assembly 230 at the ICG 232 propagates through the OPE 234 and is coupled into the EPE 236. After propagating toward the peripheral region of the lens frame, the light is output from the EPE 236 toward the viewer or user.

[0031] Light exits EPE 236 at a non-normal angle, e.g., a 15° angle relative to normal, such that light exits EPE 236 in a direction moving from the peripheral region toward the center of lens frame 201. Thus, EPE 236 will direct light from the peripheral region of the lens frame toward the user's right eye, creating a right field of view, e.g., a 30° x 40° (lateral x vertical) field of view on the right side of the user's field of view.

[0032] The left lens frame 202 of the eyeglasses also includes a second left pupil expander assembly 240, which includes an ICG 242, an OPE 244, and an EPE 246. Light from a fourth projector (shown here) impinges on the ICG 242 at the lower rim of the left lens frame 202, although this is not required by the present invention and other input locations can be utilized. Light coupled into the second left pupil expander assembly 240 at the ICG 242 propagates through the OPE 244 and is coupled into the EPE 246. After propagating toward the peripheral region of the lens frame, the light is output from the EPE 246 toward the viewer or user.

[0033] In a manner similar to the second right pupil expander assembly 230, but in a mirror image configuration, the EPE 246 is designed so that output light exits the EPE 246 at a non-normal angle, for example, at an angle of 15° relative to the normal. Thus, light exits the EPE 246 in a direction moving from the peripheral region toward the center of the lens frame 202. Thus, the EPE 246 will direct light from the peripheral region of the lens frame toward the user's left eye, creating a left field of view, for example, a 30° x 40° (lateral x vertical) field of view on the left side of the user's field of view.

[0034] The combination of the first right pupil expander assembly 210 and the second right pupil expander assembly 230 provides an expanded field of view for the user's right eye that combines the individual fields of view produced by each eyepiece. As an example, the left side of the right field of view can be aligned with the right side of the left field of view to provide a tiled display. In this configuration, the peripheral portions of the fields of view abut each other and define a common boundary without overlapping. In an embodiment in which the EPE 216 and the EPE 236 provide a 30° x 40° field of view, the combined field of view is 60° x 40°, effectively doubling the field of view available to the user. A similar increase in field of view is achieved for the left eye. In addition to this configuration, other configurations in which the fields of view are tiled without overlapping are within the scope of the present invention, as described more fully herein.

[0035] FIG. 3 is a simplified schematic diagram illustrating binocular field overlap according to one embodiment of the present invention. In FIG. 3, the extended field of view associated with the left eye is 60° by 40° (lateral by vertical) and is illustrated by left field of view 310 (310A spanning a 60° horizontal range and 310B spanning a 40° vertical range). The extended field of view associated with the right eye is also 60° by 40° (lateral by vertical) and is illustrated by right field of view 320 (320A spanning a 60° horizontal range and 320B spanning a 40° vertical range). A 40° binocular overlap region is achieved in this implementation, with 20° of non-overlapping field of view at the peripheral edge. This implementation allows binocular processing of data to occur within the inner 40° of field of view 330, which studies have shown is the region where the majority of binocular processing occurs. While 40° binocular overlap is provided in this example, additional overlap, including complete overlap, or reduced overlap can also be implemented. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.

[0036] As illustrated in FIG. 3, an 80° x 40° ambinocular (i.e., total) field of view 340 is provided across both eyes, resulting in a diagonal ambinocular field of view of 89°. Although two overlapping fields of view are illustrated in FIG. 3, the present invention is not limited to this particular implementation, and other numbers of fields of view can be tiled, overlapped, or combinations thereof. For example, two or more fields of view can be overlapped in the central region, and two or more additional fields of view can be tiled in the peripheral region. Those skilled in the art will recognize many variations, modifications, and alternatives.

[0037] FIG. 4A is a simplified perspective view illustrating a waveguide display 400 that produces an extended field of view, according to an embodiment of the present invention. A shared EPE 405, which may also be referred to as a diffractive output element, is provided as an element of the waveguide display that works in conjunction with light provided by more than two projectors. As illustrated in FIG. 4A , in some implementations, two OPEs are positioned on opposite sides of the shared EPE, such that the first OPE is positioned a first distance from the central normal along a first direction (e.g., the x-direction) and the second OPE is positioned a second distance from the central normal along the opposite direction (e.g., the negative x-direction). In some embodiments, the size of the EPE can be increased compared to a conventional EPE that receives light from a single OPE. The shared EPE 405 is substantially planar and characterized by an emission surface 406. A central normal 407 is a vector normal to the emission surface 406 and centered on the center of the shared EPE 405. 4A, the central normal is aligned with the z-axis. As explained more fully below, two fields of view are generated that are displaced relative to the central normal. As a result, image data associated with a first projector can be projected to form a first field of view that is displaced in a first direction relative to the central normal, and image data associated with a second projector can be projected to form a second field of view that is displaced in a second, opposite direction relative to the central normal.

[0038] The first ICG 410 receives light from a first projector (not shown) and directs the light into the plane of the waveguide along propagation path 414. As the light propagates through the first OPE 412, the light is diffracted toward the shared EPE 405. The second ICG 420 receives light from a second projector (not shown) and directs the light into the plane of the waveguide along propagation path 424. As the light propagates through the second OPE 422, the light is diffracted toward the shared EPE 405.

[0039] The EPE 405 is designed so that light entering the EPE from the first OPE 412 is diffracted to form a first emission frustum 418 centered on the first output path 416, and light entering the EPE from the second OPE 422 is diffracted to form a second emission frustum 428 centered on the second output path 426. As shown in FIG. 4A , the output paths can be along directions non-normal to the EPE's emitting surface. As an example, the first output path 426 can be oriented at 15° to one side of the normal to the EPE's emitting surface, and the second output path 428 can be oriented at −15° to the normal to the EPE's emitting surface. In this implementation, the first and second fields of view are tiled, and a central normal 407 passes through the boundaries of each of the first and second fields of view. Referring to FIG. 4A, a first emission frustum 418 defining a first field of view and a second emission frustum 428 defining a second field of view each have one side of their field of view aligned with the normal to the emission surface and an opposite side of their field of view oriented at ±30° relative to the normal.

[0040] Thus, as illustrated in FIG. 4A, a shared EPE can be used to increase the total field of view by combining a field of view associated with a first projector and a second field of view associated with a second projector. In the embodiment illustrated in FIG. 4A, the fields of view are tiled without overlap, but in other embodiments, a region of central binocular overlap, such as that illustrated in FIG. 3, can be provided as needed for a particular application. Although not required by the present invention, in some embodiments, the range of angles associated with multiple projectors and OPEs can be increased, thereby increasing the size of the combined field of view. Those skilled in the art will recognize many variations, modifications, and alternatives.

[0041] 4B is a simplified exploded perspective view illustrating a waveguide display with overlapping elements, according to one embodiment of the present invention. The waveguide display 450 illustrated in FIG. 4B shares some similarities with the waveguide display illustrated in FIG. 4A, and the description provided in connection with FIG. 4A is applicable to FIG. 4B, where appropriate. As illustrated in the exploded view shown in FIG. 4A, OPEs 412 and 422 spatially overlap with shared EPE 405, with the OPEs positioned in a first z-dimension and the shared EPE positioned in a second z-dimension.

[0042] In the embodiment illustrated in FIG. 4B, light received at ICGs 410 and 420 is directed into the plane of the waveguide. The ICGs can be positioned adjacent to each other in the xy plane, partially overlapping, or completely overlapping. By rotating the orientation and / or pitch of the diffractive elements defining the ICGs, the angle at which light propagates in the xy plane can be modified. As a result, by modifying the orientation of the diffraction gratings within the ICGs, the fields of view of two projectors mounted side-by-side can be angularly shifted relative to each other. By modifying the grating pitch, a grating with a higher frequency pitch can deflect light from the projectors at different angles, enabling the use of projectors with different orientations. It should be understood that these variations discussed in connection with FIG. 4B can be applied to the embodiments illustrated in FIGS. 4A and 6, as needed.

[0043] Propagation path 424 is illustrated for OPE 422. A similar propagation path for OPE 412 also exists, but is hidden by the shared EPE 405. As light propagates through the OPE, it is diffracted toward the shared EPE 405. As illustrated in FIG. 4B , the ICG and OPE are oriented to direct light in the same direction within the plane of the waveguide, i.e., the negative y-direction. Because light propagates in the same direction within the OPE, the orientation of the grating lines will be different (e.g., mirror image) within the OPE to direct the light toward the shared EPE. When OPE 412 and OPE 422 are positioned so that they overlap in the xy plane, the overlap of the diffraction gratings of each OPE can form a diamond-shaped diffraction pattern resulting from the overlap of the mirror-image grating lines of each OPE. In one embodiment, the diffraction elements for the OPE (e.g., diamond-pattern grating lines) can be formed on one surface of the waveguide layer, and the diffraction elements for the shared EPE (e.g., grating lines) can be formed on the opposite side of the waveguide layer.

[0044] 4A, ICG 410 directs light in the negative y-direction, and ICG 420 directs light in the positive y-direction. Thus, in this embodiment, the orientation of the grating lines can be matched to direct the diffracted light toward the shared EPE.

[0045] Figure 5A is a simplified perspective view illustrating a waveguide display producing multiple depth planes, according to one embodiment of the present invention. The waveguide display 500 illustrated in Figure 5A shares some similarities with the waveguide display illustrated in Figure 4A, and the description provided in connection with Figure 4A is applicable to Figure 5A, where appropriate.

[0046] A shared EPE 505 is provided on a waveguide display that works in conjunction with light provided by more than two projectors. A first ICG 510 receives light from a first projector (not shown) and directs the light into the plane of the waveguide along a propagation path 514. As the light propagates through the first OPE 512, it is diffracted toward the shared EPE 505. A second ICG 520 receives light from a second projector (not shown) and directs the light into the plane of the waveguide along a propagation path 524. As the light propagates through the second OPE 522, it is diffracted toward the shared EPE 505.

[0047] The EPE 505 is designed to include refractive power. Thus, light entering the EPE from the first OPE 512 is diffracted to form a first emission frustum 518 having a diverging wavefront. A central ray 507 of the first emission frustum, which is also normal to the surface 506 of the EPE 505, is illustrated as being directed away from the EPE toward the user. While the first emission frustum 518 is illustrated in FIG. 5A as being positioned at the center of the EPE, it will be apparent to one skilled in the art that emission occurs across the surface 506 of the EPE 505, and the illustrated frustum is limited to only the central region for purposes of clarity.

[0048] 5A, first emission frustum 518 is directed along a direction normal to the emitting surface of the EPE (i.e., central ray 507 is normal to the emitting surface), and the virtual source of first emission frustum 518 is located at a position below the plane of the waveguide and EPE 505. Although the light emitted from the EPE is illustrated as being normal to the emitting surface, this is not required by the present invention, and other emission angles are within the scope of the present invention.

[0049] Light entering the EPE from the second OPE 522 is diffracted to form a second emission frustum 528 having a converging wavefront. The central ray of the second emission frustum 528 is also illustrated as being directed away from the EPE toward the user. As further illustrated in FIG. 5A , the focus of the second emission frustum is located in front of the plane of the waveguide or the emission surface of the EPE. In the illustrated embodiment, both emission frustums are centered normal to the emission surface of the waveguide and can be aligned with the center of the EPE and / or the center of the waveguide display. Thus, while the second emission frustum 528 is illustrated as being centered on the EPE, it will be apparent to those skilled in the art that emission occurs across the EPE and that the illustrated frustum is limited to only the central region for purposes of clarity.

[0050] FIG. 5B is a simplified side view illustrating the integration of a lens with the waveguide display illustrated in FIG. 5A. The waveguide display 500 emits light toward the eye 550, with one diverging beam having a negative refractive power (e.g., a refractive power of −0.33 diopters) and one converging beam having a positive refractive power (e.g., a refractive power of +0.33 diopters). The lens 540 is integrated with the waveguide display and can be either a negative or a positive lens. In the implementation illustrated in FIG. 5B, the lens 540 is a negative lens (e.g., having a refractive power of −0.66 diopters). As the first emission frustum 518 passes through the lens 540, the refractive power will be modified, for example, to −1.0 diopters, and as the second emission frustum 528 passes through the lens 540, the refractive power will be modified, for example, to −0.33 diopters. As a result, in this example, the first emission frustum would be associated with a 1 meter depth plane, and the second emission frustum would be associated with a 3 meter depth plane.

[0051] A second lens 542, which may be a positive lens, is integrated with the waveguide display and can compensate for the refractive index of lens 540. As shown in FIG. 5B, a positive lens with a refractive power equal to the absolute value of the refractive power of lens 540 is used to allow light from the world to pass to the user's eye 550 without altering the view of the world. The use of lenses 540 and 542 can encapsulate the waveguide display and provide reliability. Additionally, one or more of the lenses can be modified to provide the appropriate prescription for the user.

[0052] Although refractive lenses 540 and 542 are illustrated in FIG. 5B , embodiments of the present invention are not limited to these implementations; holographic elements, diffractive surfaces, metasurfaces, and the like can be utilized in accordance with embodiments of the present invention. For example, lens 540 can be a diffractive surface, metasurface, or the like. Furthermore, one or more of the lenses illustrated in FIG. 5B can also be implemented using a diffractive structure or a combination of diffractive and / or refractive structures. An example would be a diffractive structure for compensating for chromatic aberration and a refractive structure for focusing light received from the world. Those skilled in the art will recognize many variations, modifications, and alternatives.

[0053] To provide multiple depth planes for an RGB system, three waveguide display devices can be utilized, each providing two depth planes in one of the RGB colors. Those skilled in the art will recognize many variations, modifications, and alternatives.

[0054] Figure 6 is a simplified schematic plan view illustrating a waveguide display producing a tiled field of view, according to one embodiment of the present invention. The waveguide display illustrated in Figure 6 shares some similarities with the waveguide display illustrated in Figure 4, and the description provided in connection with Figure 4 is applicable to Figure 6, where appropriate.

[0055] 6, four projectors (not shown) are used to drive a shared EPE 605. Four ICGs 610, 620, 630, and 640 are used to direct light from corresponding projectors to four OPEs 612, 622, 632, and 642. Because the operation of OPEs 632 and 642 is similar in a mirror image manner, for purposes of clarity, only the operation of OPEs 612 and 622 will be discussed.

[0056] As light propagates through OPE 612, it is diffracted toward shared EPE 605 at a first angular offset. As light propagates through OPE 622, it is diffracted toward shared EPE 605 at a second angular offset. Thus, light from OPE 612 is diffracted within the shared EPE to form a first emission frustum 618 centered on first output path 616, and light entering the shared EPE from OPE 622 is diffracted to form a second emission frustum 628 centered on second output path 626. Note that although the emission frustums are illustrated as overlapping one corner of the shared EPE, light would be outcoupled from the EPE across the entire EPE, forming the four emission frustums shown. 4A, the relationship between the emission frustums and the EPEs illustrated in FIG. 6 can be understood, with light traversing the EPEs and outcoupled from the EPEs forming one of the four illustrated emission frustums corresponding to each of the corresponding OPEs. Thus, the emission frustums correlate with the field of view of the corresponding OPE, resulting in a tiled output characterized by an expanded field of view compared to the field of view of the individual OPEs. Thus, while the first emission frustum 618 is illustrated as being positioned across the upper left quadrant of the shared EPE 605, this is not intended to imply that the light contained within the first emission cone originates solely from the upper left quadrant of the shared EPE.

[0057] Although not visible at the scale of FIG. 6 , diffractive features, e.g., grating teeth, are illustrated by the shading of OPE 612 and OPE 622 and are oriented to diffract light toward the shared EPE 605. While light from OPE 612 is illustrated as diffracted within the shared EPE to form a first emission frustum 618 centered on the first output path 616, in other embodiments, light is diffracted within the shared EPE to form emission frustums adjacent to the corresponding OPE. In this embodiment, light would be emitted using the following correspondence: OPE 612 corresponding to the lower right frustum, OPE 622 corresponding to the upper right frustum, OPE 632 corresponding to frustum 628, and OPE 642 corresponding to frustum 618. In this configuration, propagation paths within the shared EPE are reduced, potentially improving optical performance, including image brightness.

[0058] Referring to FIG. 6 , OPE 612 and OPE 622 are spatially separated from each other in the xy plane. In other embodiments, OPE 612 and OPE 622 are positioned such that the inner edge of the OPE is aligned with the outer edge of EPE 605. Thus, a gap between the various elements is not required, but can be utilized as desired. In yet other embodiments, an overlapping geometry is utilized in which a portion of a first OPE is positioned at the same xy location as a portion of a second OPE. In this overlapping geometry, the diffraction grating associated with the first OPE and the diffraction grating associated with the second OPE can be formed on one side or one surface of the waveguide layer. In other embodiments, these diffraction gratings can be positioned in different z-dimensions. Furthermore, while OPE 612 and OPE 622 are spatially separated from the shared EPE 605 in the xy plane, in other embodiments, a portion of one or more of the OPEs can be positioned at the same xy location as a portion of the shared EPE. In one embodiment of an overlapping geometry, a portion of one or more of the OPEs is positioned in a first z-dimension and a portion of the shared EPE is positioned in a second z-dimension. As an example, a diffraction grating associated with an OPE can be formed on one side of a waveguide layer, while a diffraction grating associated with a shared EPE can be formed on the other side of the waveguide layer. In other embodiments, the diffraction gratings for a portion of the OPE and a portion of the shared EPE can be formed on the same surface. A similar layout is applicable to OPE 632 and OPE 642. Thus, embodiments of the present invention provide implementations in which OPEs can overlap each other, an OPE can overlap a shared EPE, or the like.

[0059] As illustrated in FIG. 6 , the emission frustums can be aligned to form a tiled output with an extended field of view that combines the fields of view as shown. Utilizing four OPEs with a shared EPE 605 allows for a 2×2 tiling of the field of view, with OPE 612 providing an emission frustum 618 as light is diffracted to the upper left by the shared EPE, OPE 622 providing an emission frustum 628 as light is diffracted to the lower left by the shared EPE, OPE 632 providing a third emission frustum as light is diffracted to the upper right by the shared EPE, and OPE 642 providing a fourth emission frustum as light is diffracted to the lower right by the shared EPE. Depending on the particular application, the fields of view can be adjacent to each other with aligned edges to provide an extended field of view defined by the sum of the individual fields of view, or can overlap as illustrated in FIG. 3 . In some embodiments, the ambinocular diagonal field of view is 134°.

[0060] It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to those skilled in the art and are to be included within the spirit and purview of the present application and the scope of the appended claims.

Claims

1. a first diffractive input waveguide operable to receive input data from a first projector and to diffract image data associated with said first projector at a first angular offset; a second diffractive input waveguide operable to receive input data from a second projector and to diffract image data associated with the second projector at a second angular offset; a diffractive output waveguide optically coupled to the first diffractive input waveguide and the second diffractive input waveguide, the diffractive output waveguide receiving the image data associated with the first projector and the image data associated with the second projector; directing image data associated with the first projector to a first field of view; a diffractive output waveguide operable to direct image data associated with the second projector to a second field of view.

2. 2. The waveguide display of claim 1, wherein the absolute values ​​of the first and second angular offsets are equal.

3. 2. The waveguide display of claim 1, wherein the diffractive output waveguide has a central normal, the first field of view and the second field of view are tiled, and the central normal passes through a boundary of each of the first field of view and the second field of view.

4. 10. The waveguide display of claim 1, wherein image data associated with the first projector has a first wavefront characterized by a first refractive power, and image data associated with the second projector has a second wavefront characterized by a second refractive power different from the first refractive power.

5. 10. The waveguide display of claim 1, wherein the first diffractive input waveguide, the second diffractive input waveguide, and the diffractive output waveguide are coplanar.

6. 10. The waveguide display of claim 1, further comprising a first input coupling element optically coupled to the first diffractive input waveguide and a second input coupling element optically coupled to a second diffractive input waveguide.

7. 7. The waveguide display of claim 6, wherein the first input coupling element, the first diffractive input waveguide, the second input coupling element, the second diffractive input waveguide, and the diffractive output waveguide are coplanar.

8. 2. The waveguide display of claim 1, wherein the first diffractive input waveguide is disposed on a first side of the diffractive output waveguide and the second diffractive input waveguide is disposed on the first side of the diffractive output waveguide.

9. a third diffractive input waveguide operable to receive input data from a third projector and to diffract image data associated with the third projector at a third angular offset; a fourth diffractive input waveguide operable to receive input data from a fourth projector and to diffract image data associated with the fourth projector at a fourth angular offset; the diffractive output waveguide is optically coupled to the third diffractive input waveguide and the fourth diffractive input waveguide; directing image data associated with the third projector to a third field of view; 9. A waveguide display as claimed in claim 8, operable to direct image data associated with said fourth projector to a fourth field of view.

10. 10. The waveguide display of claim 9, wherein the absolute value of the first angular offset is equal to the absolute value of the third angular offset, and the absolute value of the second angular offset is equal to the absolute value of the fourth angular offset.

11. 10. The waveguide display of claim 9, wherein each of the first field of view, the second field of view, the third field of view, and the fourth field of view is characterized by a lateral dimension and forms an extended field of view having a size equal to four times the lateral dimension.

12. 2. The waveguide display of claim 1, wherein the diffractive output waveguide is disposed in a plane, and the first diffractive input waveguide and the second diffractive input waveguide are spatially separated in the plane.

13. The waveguide display of claim 1 , wherein the waveguide display is disposed within eyeglasses.

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