Wearable Display System

Abstract

In a general aspect, a wearable display system includes a microlens array projector including a plurality of elemental microlens relays (EMRs). Each EMR of the plurality of EMRs includes a micro LED microdisplay including a plurality of pixels and is configured to generate a subset of light associated with an image. Each EMR also includes a microlens configured to receive the subset of light from the microdisplay. The system also includes an in-coupling element optically coupled to the light guide and an out-coupling element optically coupled to the light guide. The microlens is configured to relay the subset of light to the in-coupling element. The in-coupling element is configured to in-couple the subset of light into the light guide. The out-coupling element is configured to out-couple a portion of the subset of light at a plurality of respective locations along the light guide, the out-coupled light of the plurality of EMRs representing an image.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This is a non-provisional conversion of and claims the benefit of U.S. Provisional Patent Application No. 63 / 299,322, filed January 13, 2022, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to display devices, and more particularly to display devices that may be included in user wearable devices such as augmented reality or virtual reality glasses. [Background technology]

[0003] Displays implemented using light guide eyepieces are increasingly being used in wearable components for augmented reality ("AR") and virtual reality ("VR") applications, such as AR and VR glasses. Such display systems can be used to generate images within a large eyebox and accommodate a wide range of interpupillary distances ("IPDs") and ocular rotations of users. In such displays, a projector can be used to generate light, which is transmitted into a light guide. For example, in prior approaches, the projector converts light from a pixel light source (e.g., a spatial light modulator ("SLM")) into a collimated, angle-varying beam that is fed into the light guide eyepiece. Such prior projectors can be undesirably large, especially for wearable display applications. Furthermore, such prior projectors generate only a single external pupil, which is positioned near or coincident with an incoupling element ("ICE"), such as an incoupling grating ("ICG"), prism, or mirror that is integrally formed with or otherwise coupled to the light guide. This single pupil is an etendue choke point that limits system efficiency and can have significant drawbacks for light guide eyepieces, such as light transmission efficiency, image quality, and undesirably long light transmission track lengths and projector volumes. Summary of the Invention

[0004] In a general aspect, a wearable display system includes a microlens array projector including a plurality of elemental microlens relays (EMRs). Each EMR of the plurality of EMRs includes a microLED microdisplay including a plurality of pixels. The microLED microdisplay is configured to generate a subset of light associated with an image. Each EMR also includes a microlens configured to receive the subset of light from the microLED microdisplay. The system also includes a light guide, an input coupling element optically coupled to the light guide, and an output coupling element optically coupled to the light guide. The microlens is configured to relay the subset of light to the input coupling element. The input coupling element is configured to incouple the subset of light into the light guide. The output coupling element is configured to outcouple a portion of the subset of light at each of a plurality of locations along the light guide, where the outcoupled light of the plurality of EMRs represents an image.

[0005] Implementations may include one or more of the following aspects or features, alone or in combination: For example, the subset of light may be replicated by the light guide at least three times before the light is outcoupled by the output coupling element.

[0006] Less than 10% of the subset of light is outcoupled by the input coupling element.

[0007] The microLED microdisplay may be located less than 15 millimeters from the light guide.

[0008] The microlenses can be monolithically integrated with the microLED microdisplay.

[0009] The volume of a microlens array projector can be less than 0.1 cubic centimeters.

[0010] MicroLED microdisplays can be configured to emit light with a brightness of at least 500,000 nits.

[0011] The multiple EMRs may be arranged in a non-linear pattern. The EMRs may be unevenly spaced from one another.

[0012] The light subset may include 5% to 50% of the image. The input coupling element may include a plurality of distinct input coupling element regions. A first input coupling region of the plurality of distinct input coupling element regions may have a first shape and a second input coupling region of the plurality of distinct input coupling element regions may have a second shape different from the first shape. The plurality of distinct input coupling element regions may be regularly spaced. The plurality of distinct input coupling element regions may be irregularly spaced.

[0013] The light guide may have a real-world surface opposite the user-side surface, and the microlens array projector may be disposed on the real-world surface.

[0014] The light guide may be a first light guide, and the wearable display system may include a second light guide. The second light guide may be positioned in a coplanar position relative to the first light guide. The second light guide may be positioned in an overlapping position relative to the first light guide.

[0015] The subset of light may be one of red light for images in the wavelength range of 590 to 680 nanometers (nm), green light for images in the wavelength range of 510 to 570 nm, or blue light for images in the wavelength range of 430 to 490 nm.

[0016] The input coupling element may be one of a diffractive input coupling element or a reflective input coupling element.

[0017] The output coupling element may be one of a diffractive output coupling element or a reflective output coupling element.

[0018] In another general aspect, a wearable display system includes a first elemental microlens relay (EMR), the first EMR including a first microdisplay configured to generate a first subset of light associated with an image and a first microlens configured to receive the first subset of light from the first microdisplay. The system further includes a second EMR, the second EMR including a second microdisplay configured to generate a second subset of light associated with the image and a first microlens configured to receive the second subset of light from the second microdisplay. 2 The system also includes a third EMR, the third EMR including a third microdisplay configured to generate a third subset of light associated with the image, and a third EMR configured to receive the third subset of light from the third microdisplay. 3 and a microlens of the first light. The system further includes a light guide and a first input coupling element optically coupled to the light guide. The first input coupling element is configured to incouple the first subset of light into the light guide. The system also includes a second input coupling element optically coupled to the light guide. The second input coupling element is configured to incouple the second subset of light into the light guide. The system further includes a third input coupling element optically coupled to the light guide. The third input coupling element is configured to incouple the third subset of light into the light guide. The system further includes an output coupling element configured to outcouple the first subset of light, the second subset of light, and the third subset of light to display an image.

[0019] Implementations may include one or more of the following aspects or features, alone or in combination: For example, a first subset of lights may correspond to a first subset of angles of the field of view of the image, a second subset of lights may correspond to a second subset of the field of view of the image that is different from the first subset of angles, and a third subset of lights may correspond to an angle of a third subset of the field of view of the image that is different from the first subset of angles and the second subset of angles.

[0020] The first input coupling element can be configured to incouple light at a first subset of angles of the image field of view, the second input coupling element can be configured to incouple light at angles of a second subset of the image field of view that is different from the first subset of angles, and the third input coupling element can be configured to incouple light at a third subset of angles of the image field of view that is different from the first subset of angles and the second subset of angles.

[0021] The first subset of lights may include red lights of the image, the second subset of lights may include green lights of the image, and the third subset of lights may include blue lights of the image.

[0022] The outcoupling element may include multiple outcoupling element regions. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 illustrates a wearable display system having a microlens array projector (“MLAP”), according to an exemplary embodiment. [Figure 2] FIG. 1 illustrates a mathematical comparison between a prior art projector system and an exemplary MLAP system. [Figure 3] FIG. 1 illustrates rebound in a light guide eyepiece system. [Figure 4] 1A-1C illustrate front and top views of a rectilinear MLAP system with variable bounce, according to an exemplary embodiment. [Figure 5] 1A-1C illustrate front views of each non-linear MLAP arrangement, according to an exemplary embodiment. [Figure 6] 1A-1C illustrate front views of each non-linear MLAP arrangement, according to an exemplary embodiment. [Figure 7] FIG. 1 illustrates a top view of an MLAP system, according to an exemplary embodiment. [Figure 8] 1A-1C illustrate top views of ray tracing diagrams of various MLAP projector arrangements, according to exemplary embodiments. [Figure 9] 1A-1C illustrate top views of ray tracing diagrams of various MLAP projector arrangements, according to exemplary embodiments. [Figure 10] 1A-1C illustrate top views of ray tracing diagrams of various MLAP projector arrangements, according to exemplary embodiments. [Figure 11] 1A-1C illustrate top views of ray tracing diagrams of various MLAP projector arrangements, according to exemplary embodiments. [Figure 12A] 12A and 12B show top views of ray tracing diagrams comparing the optical track length of a prior art projector system (FIG. 12A) with the optical track length of an MLAP system (FIG. 12B). [Figure 12B] 12A and 12B show top views of ray tracing diagrams comparing the optical track length of a prior art projector system (FIG. 12A) with the optical track length of an MLAP system (FIG. 12B). [Figure 13] FIG. 1 illustrates a top view of a wearable display having a wrapped form factor, according to an exemplary implementation. [Figure 14] 1A-1C show top views of an exemplary wearable display including an MLAP on the real-world side in a flush configuration and a wrap configuration, respectively, according to an exemplary embodiment. [Figure 15] 1A-1C show top views of an exemplary wearable display including an MLAP on the real-world side in a flush configuration and a wrap configuration, respectively, according to an exemplary embodiment. [Figure 16] 1A-1C illustrate exemplary sizes and locations of MLAPs relative to a wearable eyeglass frame, according to an exemplary embodiment. [Figure 17] 1A-1C illustrate exemplary sizes and locations of MLAPs relative to a wearable eyeglass frame, according to an exemplary embodiment. [Figure 18] 1A and 1B illustrate front and top views of an MLAP system having a single shared backplane configured to provide image light to both the left and right eyes of an observer, according to an exemplary embodiment. [Figure 19] FIG. 2 illustrates a front view of an exemplary MLAP system relative to a backplane layout, according to an exemplary implementation. [Figure 20] FIG. 1 illustrates a top view of an MLAP system including a diffractive coupling element, according to an exemplary embodiment. [Figure 21A] FIG. 1 illustrates an MLAP system including a reflective coupling element, according to an exemplary embodiment. [Figure 21B] FIG. 1 illustrates an MLAP system including a reflective coupling element, according to an exemplary embodiment. [Figure 21C] FIG. 1 illustrates an MLAP system including a reflective coupling element, according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] Like reference symbols in various drawings indicate like elements. Reference numbers of some like elements may not be repeated for all such elements. In certain instances, different reference numbers may be used for like or similar elements. Some reference numbers of particular elements of a given embodiment may not be repeated in each drawing corresponding to that embodiment. Some reference numbers of particular elements of a given embodiment may be repeated in other drawings corresponding to that embodiment, but may not be specifically described with reference to each corresponding drawing. The drawings are intended to illustrate illustrative embodiments and may not necessarily be drawn to scale.

[0025] The techniques and approaches described herein result in creating smaller projectors with higher incoupling efficiency and shorter optical tracker lengths than prior projectors, while facilitating larger eyeboxes for displayed images in associated systems. In exemplary embodiments, the projectors disclosed herein enable the implementation of lighter, more compact, more power-efficient, and lower-cost wearable components for augmented reality (AR) and virtual reality (VR) displays.

[0026] For example, the present disclosure provides an example of a compact projector capable of transmitting more light into a light guide eyepiece than prior projectors. Systems using the disclosed projectors in combination with a pupil-widening light guide advantageously produce large eyeboxes and high-quality images for observers. One aspect of the disclosed embodiments is the use of a lenslet (microlens) array instead of a single-axis, multi-element, typically single-pupil, projection lens, as in prior approaches. Each lenslet in the lenslet array is configured to transmit a subset of the total pixels present in the complete image into the waveguide through its own respective pupil. Because each lenslet transmits only a subset of the angles encompassing the corresponding system's full field of view, such a lenslet-based design can be simpler than prior projectors that use a single large lens arrangement, such as a complex stack of lenses, to transmit all image display angles from a single display pixel array through a single pupil.

[0027] Furthermore, because the exemplary display systems (projectors) disclosed herein may include light guides, they differ from systems used to achieve free-space projection onto a screen. For example, in systems intended for free-space projection, the angular distribution of the quasi-parallel beams associated with each pixel intersects a common pupil; in fact, the beams collectively define the pupil. In display systems using light guide eyepieces such as those disclosed herein, subsets of pixel rays may be generated that do not collectively define a common pupil, but when these subsets of pixel rays are coupled into a pupil-widening light guide eyepiece (e.g., an exit pupil expander (EPE)), a common eyelid (dilated pupil) is formed. The (observer's) eye, positioned within the eyebox, can then interpret all subsets of pixel rays as emanating from their appropriate positions and appropriate angular directions, thereby accurately perceiving the entire image field by the observer.

[0028] This separation between the projector pupil entering the light guide and the observer pupil (e.g., eyebox) exiting the light guide allows for the combination of pixel groups, projection optics, and in-coupling elements (input coupling elements, incouplers, etc.) that can offer several advantages. Prior projectors with single-aperture optical layouts require a trade-off between system volume and projected light flux due to etendue limitations. In contrast, lenslet array projection systems may overcome at least some of the limitations of prior systems through the use of an optical multiple-aperture setup that uses an array of microlenses as the projection objective. In the case of a microlenslet array projector ("MLAP"), several separate apertures or pupils are created and spatially distributed using lenses with relatively low complexity compared to prior projectors.

[0029] FIG. 1 illustrates a system 100 including an MLAP 102 and a light guide eyepiece 106. In this example, the MLAP 102 includes multiple elemental microlens relays (“EMRs”), such as EMRs 110. While the EMRs 110 are shown with equal spacing between adjacent EMRs 110 (e.g., regularly spaced), in some implementations, the EMRs may be spaced differently (unevenly, non-uniformly, etc.). For example, the EMRs may be arranged in a regular grid or hexagonally packed configuration, although they may also be irregularly spaced or positioned such that the configuration lacks a regular pattern and may be considered a collection of EMR components. Each of the EMRs 110 of the MLAP 102 includes a microlens 105 and an elemental microdisplay 104. The elemental microdisplay 104 may include multiple pixels. For a given EMR 110, the microlens 105 is configured to receive light from a corresponding elemental microdisplay 104. Each pixel of the elemental microdisplay 104 may include, for example, one or more microLEDs. For example, each pixel may include one red, one green, and one blue microLED. Each EMR 110 may be configured to generate and relay light associated with a subset (e.g., a pixel group) of the total field of view to an incoupling element 112 on the light guide eyepiece 106. Each subset of light may then travel through the light guide eyepiece 106 until it reaches an outcoupling element 114 (outcoupling element, outcoupler, etc.). In some embodiments, several outcoupling elements, or an array of outcoupling elements, may be collectively configured to redirect a portion of the light exiting the light guide toward the observer's eye 120 across an area creating an eyebox. When the observer's eye 120 is located within the eyebox region, the observer's eye 120 receives light associated with all portions of the field of view.

[0030] The use of self-emissive microdisplays for the elemental microdisplays 104 may reduce the volume of the system 100 compared to prior approaches that use external light sources and spatial light modulators ("SLMs"). For example, microLED-based microdisplays may enable high brightness in a small volume. In some examples, microLED microdisplays may have a pixel pitch in the range of 1 to 10 micrometers (um) (or in the range of 2 to 5 um, or in the range of 0.5 to 3 um). Each pixel may include multiple light emitters (e.g., one red, one green, and one blue subpixel).

[0031] In some embodiments, a microLED elemental microdisplay may have a pixel count in the range of 1,000 to 10,000 (or in the range of 10,000 to 100,000, or in the range of 100,000 to 1 million (M), or in the range of 1 to 10 M). The total resolution of a corresponding display system including multiple microdisplays may be approximately equal to the sum of the resolutions of the included microdisplays (e.g., sub-microdisplays). In some embodiments, each elemental microdisplay may have a lateral dimension (e.g., width and / or height of the microdisplay area) of less than 10 millimeters (mm) (or less than 5 mm, or less than 4 mm, or less than 3 mm, or less than 2 mm, or less than 1 mm, or less than 500 um). The elemental microdisplay may have a brightness of at least 0.1 million nits (Mnit) (or at least 0.5 Mnit, or at least 1 Mnit, or at least 2 Mnit, or at least 5 Mnit, or at least 10 Mnit, or 50 Mnit, or at least 100 Mnit). The lightness may be calculated when displaying a substantially white image (e.g., a white image having a chromaticity of D65).

[0032] Because the volume of the self-luminous microdisplays is reduced, compared to previous projectors, the MLAP (including the backplane, multiple microdisplays, and corresponding lenses) can have a total volume of less than 1 cc (cubic centimeter), or less than 0.5 cc, or less than 0.2 cc, or less than 0.1 cc.

[0033] In disclosed embodiments, by subdividing the system field of view, the MLAP architecture enables an etendue versus track length tradeoff not available in prior projectors. This tradeoff is sometimes referred to as a lens design complexity versus track length trade, since aberration correction at smaller fields of view can be achieved using fewer lens elements. The size of an EMR (such as the EMR 110) may be limited by the desired etendue and / or manufacturing design rules. For example, in a short-track-length MLAP, the field of view associated with each microlens is a fraction (e.g., 1 / 9 or less) of the system's total field of view, and each EMR may have a correspondingly small etendue. This facilitates a simpler approach to aberration correction when compared to prior projectors that pass a large portion or the entire field of view through a single, complex stack of relay lenses. In some embodiments, each EMR in an MLAP may have equivalent aberration correction (for its respective field of view) to such a complex lens stack using fewer, smaller, and / or simpler optical elements.

[0034] Furthermore, because MLAP systems can be implemented without complex stacks of relay optics, the overall length of the corresponding optical track (e.g., the physical distance between the elemental microdisplay 104 and the incoupling element 112) can be significantly reduced. Furthermore, because image and viewing angle information is distributed across multiple pupils, each pupil can be associated with a separate (distinct) incoupling element. By distributing the light from the MLAP across several incoupling elements, the efficiency of the overall display system can be improved at this critical throughput choke point. If the track length can be increased in stages, the efficiency can be further improved.

[0035] In some implementations of system 100 (and other MLAP systems described herein), each EMR of MLAP 102 may each correspond to a particular color / wavelength of light. For example, a first plurality of EMRs may include microdisplays that emit red light (e.g., a wavelength range of 590-680 nanometers (nm)), a second plurality of EMRs may include microdisplays that emit green light (e.g., a wavelength range of 510-570 nm), and a third plurality of EMRs may include microdisplays that emit blue light (e.g., a wavelength range of 430-490 nm). The incouplers used to couple a particular wavelength / color into the light guide may be configured to improve efficiency at that wavelength / color, e.g., compared to other wavelengths / colors. For example, in this example, a first intercoupler can be configured to couple red light from a first plurality of EMRs into the light guide, a second intercoupler can be configured to couple green light from a second plurality of EMRs into the light guide, and a third intercoupler can be configured to couple blue light from a third plurality of EMRs into the light guide.

[0036] In some embodiments, the above approaches can be combined with tuning (constructing, generating, etc.) each incoupler for the angle of incidence. That is, the incoupler can be configured to efficiently incouple light of a given color / wavelength and angle of incidence (or range of angles of incidence). Separating the incouplers by wavelength can reduce double-bounce losses. In some embodiments, the incoupler can receive spectrally dispersed radiation (e.g., light) with a full width at half maximum of less than 100 nm (or less than 50 nm, or less than 30 nm), and the thickness of the incoupler and light guide is configured to reduce double-bounce losses for the radiation; in some examples, less than 20% (or less than 10%, or less than 5%) of the power of the radiation is lost to double-bounce losses at the incoupler. The outcoupling element can also be configured to efficiently outcouple each color / wavelength and / or each angle of incidence (or each range of angles of incidence). Further segmentation of the wavelength range is possible. For example, a first EMR may emit light with a first peak wavelength (e.g., in the range of 590-610 nm) and be coupled to a first in-coupler, a second EMR may emit light with a second peak wavelength (e.g., in the range of 610-630 nm) and be coupled to a second in-coupler, and both the first and second EMR may contribute light of the same color (e.g., red in this example).

[0037] This can further be combined with separate light guides for different colors. For example, a first light guide can have red in-coupler and out-coupler elements and can be coupled to one or several red-emitting EMRs, and similarly for green and blue. In some embodiments, one light guide can carry one color (e.g., red) and another light guide can carry two colors (e.g., blue and green). This can increase the freedom of light guide thickness selection and reduce double-bounce losses.

[0038] 2, equations are shown that describe the relationship between prior projection system 200a and MLAP system 200b in terms of etendue (E), optical track length (f), and pupil area. In this example, the etendue (E) of prior projection system 200a is similar to the etendue (E) of MLAP system 200b, but the optical track length of MLAP system 200b is significantly reduced (e.g., reduced to about half of the optical track of prior projection system 200a), and the pupil area of ​​MLAP system 200b is increased by an order of magnitude compared to the pupil area of ​​prior projection system 200a. Thus, MLAP systems such as those described herein can offer size advantages, e.g., reduced physical projector size, compared to prior projection systems while supporting the same or a wider field of view.

[0039] In an MLAP system, the location of the EMR and the design of the incoupling element should be considered because of the possibility of light rebound. Light rebound is illustrated in FIG. 3. As shown in FIG. 3, when light 308 intended to interact once with a first incoupling element 312 interacts with the incoupling element 312 a second time in an associated light guide (light guide 306) or encounters a second incoupling element (not shown in FIG. 3) along its optical path in the light guide 306, the rebound portion 316 of the light 308 may be outcoupled from or mispropagated within the light guide 306 before reaching the intended outcoupling element. The embodiments disclosed herein are useful for mitigating the problem of "rebouncing," or the re-encounter of an incoupling grating by a launched beam. Such embodiments may reduce or eliminate rebound, thereby improving image quality and system efficiency while reducing unwanted stray light in the system. When designing an EMR and ICE layout that reduces or eliminates rebounce, variables such as the thickness of the light guide substrate, the pupil width, and the width of the incoupling element may be considered.

[0040] As noted above, the location of the EMR components may not be in a rectilinear grid and may be arranged in clusters or irregular configurations. To provide additional design freedom in embodiments in which the angular distribution of image information across a composite field of view is distributed among distinct pixel groups and EMRs, the locations of these pixel groups / EMRs may be in any suitable location. Each pixel group may correspond to an elemental microdisplay. This location freedom is a result of the function of the light guide eyepiece as a tiling mechanism, appropriately positioning portions of the field of view depending solely on the range of viewing angles associated with the pixel information present in the eyepiece light guide, as shown in FIG. 1 . In some implementations, it may be beneficial to adjust the spacing of the EMRs along a plane parallel to the eyepiece waveguide to minimize the spacing between the MLAP and the associated light guide eyepiece.

[0041] Separating image component locations (e.g., EMR locations) and pupil locations (e.g., the location of each pupil projected into the light guide by each EMR) can provide certain advantages. For example, because the image information in the eyepiece light guide is in the form of parallel, quasi-collimated light beams that propagate with the correct direction vector in total internal reflection (TIR) ​​within the light guide and exit upon encountering an outcoupling element, the spatial positioning of the EMRs and the locations where different image components are launched into the light guide do not affect the observer's eyebox or the displayed image. The EMR location variable can be manipulated to reduce bounce in display systems using an MLAP projector configuration.

[0042] FIG. 4 illustrates how rebooting can affect an MLAP system. For example, on the left side of FIG. 4, a front view of an MLAP system 402 is shown above an incoupling element 412 (e.g., an incoupling grating (ICG)). On the right side of FIG. 4, a top view of the MLAP system 402 is shown along with a light guide 406 in which the incoupling element 412 is disposed. The incoupling element 412 is configured to receive light from the MLAP system 402 and redirect the light (e.g., along a propagation vector 418) so that the light couples into the light guide 406 and continues traveling through the light guide 406 while undergoing TIR. As shown in FIG. 4, the MLAP system 402 includes multiple EMRs 410, each represented by a circle in the front view (left). In some configurations, an MLAP system with EMRs arranged in a grid, as shown in FIG. 4, can experience rebounce as shown in the right diagram and with a rebounce budget shown in the left diagram. For example, EMR 410a directs light 420 toward incoupling element 412. Due to variables including the pupil position of EMR 410a on incoupling element 412, the thickness of light guide 406, and the propagation vector 418 along which incoupling element 412 directs the incident light, light 420 interacts with incoupling element 412 twice. Upon the second interaction, a portion of light 420 exits light guide 406 as a rebounce beam 422. In the example shown in FIG. 4, light emanating from EMR 410 (including EMR 410a), which is shown in an unshaded state, may experience at least some rebounce, while light emitted from EMR 410 may not experience any rebounce.

[0043] To reduce or eliminate bounce along the corresponding propagation vector, the EMRs in an MLAP system may be arranged in a non-linear pattern. Furthermore, the associated ICE (ICG) may be correspondingly configured to capture light from the non-linear arrangement in such an MLAP design. While FIGS. 5 and 6 show examples of such EMR and ICG configurations, more or fewer EMRs may be included in the MLAP system, and the specific dimensions of the ICG relative to the MLAP may vary depending on the particular implementation. Furthermore, while many shapes and spacing designs are possible, the examples shown in FIGS. 5 and 6 may be advantageous for wearable display applications because the “corner” or “L-shaped” arrangement can be easily incorporated into eyeglass frames without interfering with the user's vision or adding significant bulk.

[0044] In addition to reducing or eliminating bounce, the configurations of FIGS. 5 and 6 provide for the use of a larger-area ICE (ICG) compared to the ICE used in prior projector systems. A larger ICE area may result in more efficient coupling of image information (light for the projected image) into the light guide eyepiece. Furthermore, the MLAP systems of FIGS. 5 and 6 may be segmented into two or more shifted MLAP subsystems to provide an MLAP footprint / volume that accommodates any mechanical interference or packaging issues of a particular implementation. Accordingly, the associated ICEs may also be different sizes and / or shapes. For example, in some implementations, the ICE receiving light associated with the center of the field of view may be larger than the ICE receiving light associated with the peripheral portion of the field of view. Such a configuration may improve the sharpness of pixels in the center of the field of view. To further improve image quality in the center of the field of view (or another selected portion), the lenslets associated with the center of the field of view may be manufactured from higher quality materials and / or with tighter manufacturing tolerances.

[0045] Referring to FIG. 7, a display system (system 700) is shown. System 700 includes an MLAP 702 with multiple EMRs 710, a light guide 706, ICEs 712 (each corresponding to a respective EMR 710), and an outcoupling element 714. Each EMR 710 projects a respective pupil of light containing a subset of the total field of view contained in a single image. The locations of each pupil and its corresponding ICE 712 can be laterally distributed anywhere on the light guide eyepiece. The outcoupling element 714 (e.g., a leaky output coupler) replicates each sub-pupil in the same space, creating an eyebox where the perception is a single coherent image.

[0046] A ray tracing diagram 800 is shown in FIG. 8. Determining the EMR and corresponding ICE locations to reduce or eliminate bounce can be achieved by back-ray tracing from the observer's pupil 826 through the outcoupling element 814, the light guide 806, and the ICE 812, which may include multiple ICEs. FIGS. 9-11 also show ray tracing diagrams 900, 1000, and 1100, respectively. FIGS. 9-11 illustrate three different bounce-reducing pupil ensembles. In these examples, the ensembles vary by propagation length, but the thickness of the light guide similarly affects the corresponding pupil ensembles. That is, FIGS. 9-11 illustrate how different ray bundles map to different ICGs and EMRs as the propagation length changes, and in these diagrams, the EMR locations may be non-uniformly distributed.

[0047] An additional potential advantage of MLAP projection systems is that each pupil contains a subset of the angular spectrum of the entire image, and each incoupling element acts on only its respective subset of the angular spectrum. In prior imaging systems that generate a single pupil and incouple the single pupil into the eyepiece using a single incoupling element, the incoupling element must be designed to perform equally well for all incident beam input angles. This is challenging, especially as more obtuse angles are considered, and thus requires some compromise in the design of the incoupling element (e.g., grating) to ensure uniformity of performance across the image angle space.

[0048] In an MLAP system as described herein, the image angular spectrum is spatially dispersed and subdivided across several lenslets and their associated pupils. Therefore, each incoupling element (e.g., grating) can be tuned (tuned, designed, etc.) for a corresponding EMR and its associated angular spectrum. This allows for consideration of alternative incoupling elements that may not have acceptable performance across the entire image angular spectrum. For example, in some embodiments, highly efficient but limited functional angular range volume phase gratings are used and can be configured for each incoupling element to function at a subset of each angular range, thereby improving the efficiency of the associated system. While a common surface relief structure currently in use has a blazed grating profile, other surface relief structures that may significantly improve performance across a more limited angular spectrum, such as metasurfaces and mirrors with coatings optimized for limited viewing angles, may also be used. Therefore, different designs or categories of incoupling elements may be used in a light guide depending on the characteristics of the light they are designed to interact with.

[0049] In an exemplary embodiment, the AR display system includes at least two elemental microdisplays, each coupled to at least two (optionally associated) lenses (lenslets) to form at least two EMRs. Each EMR emits light at a respective angular range around a respective primary direction, and the directions of the EMRs differ from each other. Each light of each EMR is optically coupled to a respective in-coupling element of a light guide. Each in-coupling element is designed to improve the coupling efficiency of the light around each primary direction.

[0050] 12A and 12B illustrate the relationship between focal length in a system with a single lens (FIG. 12A) and focal length in a system with multiple lenslets. For example, FIG. 12A shows system 1200a including a prior projector with a single lens. System 1200a has a focal length of f1=9. To achieve telecentric pupil formation with an incoupling element, additional light track length is required. Thus, the total light track length of system 1200a is 18 units, or twice the focal length. By comparison, system 1200b of FIG. 12B with three lenslets (e.g., n=3) has a focal length of f1=9, according to an equation that quantifies the focal length of a lenslet as a relationship approximately equal to the focal length of a single lens divided by the number of lenslets. n = 3. Furthermore, in an MLAP system, telecentric pupil formation at the incoupling element is not required. Therefore, no additional optical track length is needed. Thus, the optical track length of an MLAP system is equal to 3 units of focal length, or the focal length. The thickness of the light guide of system 1200b can be selected to reduce or eliminate rebounce. In particular, because an MLAP system does not require telecentricity of the light entering the light guide, the optical track length can be reduced compared to prior systems, as shown in FIGS. 12A and 12B (e.g., a 6x track length reduction).

[0051] Another potential advantage of MLAP image delivery in combination with leaky grating or beamsplitter cascade light guide eyepieces is that alignment is maintained, reducing the rigidity requirements of associated wearable displays, such as eyeglass systems. For large, previous projection systems, projector placement is limited by their size, for example, within or along the temple arms of a wearable eyeglass display to achieve a relatively compact eyeglass form factor. This placement, when combined with a surface-relief incoupling grating or mirror (in the case of beamsplitter array-type eyepieces), can be highly sensitive to angular displacement of the projector relative to the light guide eyepiece. For example, for two projectors positioned on opposing temples, differential displacement relative to each eyepiece and relative to each other can result in misalignment of the left- and right-eye images (in the case of binocular wearables). To mitigate this issue, rigid frames are typically employed to hold the eyepieces flush with each other, and rigid mounting systems are also employed to maintain the projector's position relative to the eyepieces. In some cases, it may be necessary to use active measurement devices to monitor the image in each eye and provide compensatory image adjustments if relative physical movement of the projector and eyepiece causes misalignment between them. Furthermore, these limitations effectively limit the ability to incorporate a "wrap" form factor into a wearable, for example, as shown diagrammatically in Figure 13, which is common and desirable in ophthalmic glasses and eyeglass frames.

[0052] This general class of problems can be alleviated by placing the projector on the opposite side of the eyepiece (e.g., the real-world side) with respect to the observer, as shown in Figure 14 (coplanar configuration) and Figure 15 (wrapped configuration). When the projector is mounted on the real-world side of the eyepiece (e.g., projecting light toward the user from the side of the eyepiece opposite the user), angular shifts of the projector do not shift the relative position of the displayed image in the eyepiece, and alignment can be maintained without expensive active measurement systems or rigid, heavy frames. Due to the size of prior projectors, such arrangements are not practical and consistent with the goal of creating a wearable, compact eyeglass form factor.

[0053] With continued reference to FIGS. 14 and 15, each MLAP projector 1402 and 1502 is shown on the real-world side of eyepieces 1406 and 1506, respectively. FIG. 14 shows a coplanar eyepiece configuration, while FIG. 15 shows a wrapped eyepiece configuration. Due to the significantly reduced optical track length and reduced volume achievable with the multi-lenslet MLAP systems described herein, the MLAP projector can be located on the real-world side of the eyepiece without significantly adding bulk, weight, or creating wearable balance issues. An illustration of the compact size of a corresponding real-world side of eyepiece MLAP system 1600 is shown in FIG. 16, with modeled top and perspective views of a user wearing a pair of wearable display glasses.

[0054] Additional advantages may be achieved by positioning the projectors close to each other, thereby reducing the magnitude of variation in the relative mechanical position and angle between the two projectors compared to, for example, placement on the outer portions of each lens frame of a wearable device. In such an implementation, the MLAP projectors may be positioned on the wearer's nose (e.g., on the bridge of the glasses) rather than along the left and right temples or at the outer corners of the lens frames. With prior projectors, this configuration results in a bulky and cumbersome system. Such a center-mounted projector placement may benefit from a substantially shorter light track projector, which may facilitate practical implementation of lightweight wearable AR devices.

[0055] Figure 17 shows an example of a centrally mounted MLAP 1702a in a top view of the modeled glasses. For comparison, Figure 17 also shows MLAP 1702b on the real-world side of the temple and MLAP 1702c on the user's side of the temple. MLAP 1702a, MLAP 1702b, and MLAP 1702c can operate in conjunction with corresponding light guide eyepieces and ICEs as described herein.

[0056] As described herein, MLAP projectors have a shorter track length (at the expense of a larger lateral footprint) than prior projectors. This short track length allows for practical placement of the MLAP on the real-world side of a wearable device. Furthermore, over-the-nose placement of the MLAP "pupil cluster" can be achieved with a single backplane and microLED chip, ensuring alignment and potentially reducing power requirements. In some implementations, such alignment and reduced power requirements can be achieved by using a separate backplane for each elemental microdisplay (microLED chip) in the MLAP system.

[0057] FIG. 18 illustrates a single MLAP 1802 (such as MLAP 1702a in FIG. 17) with a single backplane 1828 serving both the left and right eyes of a viewer. have FIG. 18 illustrates an example configuration of a wearable display system. In this example, a single backplane 1828 drives light emitters (e.g., micro LED chips 1804) to generate light that is projected onto multiple microlenses. A first group of microlenses 1810a directs light to a first group of incoupling elements 1812a on a light guide 1806. Due to their specific design, the incoupling elements 1812a direct light incident thereon along a first propagation vector 1818a (e.g., to the left in the illustration of FIG. 18). ) In some embodiments, light traveling in a first propagation direction along a first propagation vector 1818a encounters a first outcoupling element (not shown) and is then outcoupled from the light guide 1806 towards the user's left eye. Similarly, a second group of microlenses 1810b directs the light to a second group of incoupling elements 1812b on the light guide 1806. The incoupling elements 1812b direct light incident thereon along a second propagation vector 1818b. In an exemplary embodiment, Second Propagation Vector Light traveling in a second propagation direction along 1818b eventually encounters a second outcoupling element (not shown) and is then outcoupled from the light guide 1806 towards the user's right eye. Thus, a single backplane, one or more micro LED chips 1804, and in some embodiments, a single microlens array can be used to provide light to one or more light guide eyepieces. Such a configuration is resistant to twisting of the eyepiece support frame and allows for lighter, thinner frame designs.

[0058] Another advantage of the MLAP design relates to the distribution of pixel drive area across the associated backplane chip. In prior projector displays with a single lens, the field of pixels represents the entire image array, and there is a 1:1 correspondence between that field and the field of view of the projection system. A single lens generates a single pupil.

[0059] In contrast, the MLAP approach (shown in FIG. 19) separates sections of pixels into physically laterally distributed pixel groups 1904. Each pixel group may correspond to an elemental microdisplay (e.g., a microLED microdisplay). Multiple microlenses 1910 are each disposed above the pixel groups 1904, and each microlens 1910 may generate a pupil 1930. Notably, each of the pixel groups 1904 need not be centered with respect to its associated microlens 1910.

[0060] In some embodiments, variations are possible in coupling and outcoupling elements to and from the light guide. Such incoupling and outcoupling elements may include diffractive elements (such as surface relief gratings and / or holographic diffractive elements), reflective elements, and the like.

[0061] Alternatively, instead of using a single monolithic backplane in conjunction with multiple pixel groups, multiple backplanes can be used. For example, each pixel group can be coupled to a corresponding backplane of smaller dimensions than a single monolithic backplane, such as the arrangement shown in the top view of Figure 19. This can allow for design flexibility (because different pixel groups do not need to be coupled to the same member), reduced volume, and reduced backplane area usage.

[0062] Distributing pixels into separate groups can improve backplane cooling by spreading the display emitters over a larger area. It can also result in better utilization of the frontplane wafer, especially when wafer-to-wafer hybrid bonding is used to bond the backplane to the LED layer. In some implementations and approaches involving MLAP, pixel redundancy can also be employed, such that multiple pixels from some MLAP pixel groups can be mapped to a single image pixel. This presents an additional potential benefit of helping to mitigate any possible emitter brightness non-uniformities.

[0063] FIG. 20 illustrates an MLAP display system 2000 including a diffractive incoupling element and a diffractive outcoupling element. As shown in FIG. 20, multiple EMRs each emit a respective light. For example, EMR 2010 is shown emitting light 2010a. In this example, light 2010a from EMR 2010 is coupled (transmitted, incident, etc.) to diffractive incoupler 2012. Diffractive incoupler 2012 then diffracts (transmits) light 2010a (e.g., at least a portion of light 2010a) into light guide 2006. Light 2010a (e.g., the diffracted portion of light 2010a) then propagates through light guide 2006 and is gradually outcoupled by diffractive outcoupler 2014. Light from each of the other EMRs in the MLAP display system 2000 can be incoupled and outcoupled in a similar manner. In addition to these elements, additional replication elements (not shown) can further provide replication of the pupil.

[0064] Figures 21A-21C show a MLAP display system 2100 that includes reflective incoupling and outcoupling elements. Figure 21A shows a perspective view of the MLAP display system 2100, Figure 21B shows a top view of the MLAP display system 2100 (a view from above the view in Figure 21A), and Figure 21C shows a side view of the MLAP display system 2100. The outcoupling elements are not shown in Figures 21A and 21B.

[0065] In this example, as shown in FIGS. 21A-21C, multiple EMRs each emit a respective light. For example, EMR 2110 is shown as emitting light 2110a. In this example, light 2110a from EMR 2110 is coupled (transmitted, incident, etc.) into diffractive in-coupler 2112. Reflective in-coupler 2112 then reflects light 2110a (e.g., a portion of light 2110a) into light guide 2106 as light 2110b. Light 2110b then propagates through light guide 2106 and is gradually outcoupled by reflective out-coupler 2114. In FIG. 21C, light 2110a represents the initial emission of light by EMR 2110, and light 2110b represents the portion of light 2110a reflected by reflective in-coupler 2112. Light from each of the other EMRs in the MLAP display system 2100 can be incoupled and outcoupled in a similar manner.

[0066] In some embodiments, each EMR in the MLAP display system 2100 can be associated with a respective reflective incoupling element and / or a respective outcoupling element, and each reflective element can be configured for a particular angle of incidence and / or wavelength. Referring to FIG. 21 , multiple output mirrors 2114a are shown. In this example, each of the output mirrors 2114a outcouples a portion of the light 2110b, while the remaining portion of the light 2110b (e.g., each non-reflected portion) continues to propagate through the light guide 2106, similar to partial outcoupling at each bounce in embodiments using diffractive outcouplers.

[0067] In some embodiments, the incoupling and outcoupling elements described herein may be combined. For example, a light guide may have a reflective incoupler and a diffractive outcoupler, or vice versa. Furthermore, the reflective element may be, for example, a beam splitter, may perform a prior Fresnel reflection (aided by deposition of an optical stack to tailor the reflection), or may be implemented using a diffractive reflector (e.g., a holographic reflector).

[0068] The embodiments disclosed herein may include one or more of the following aspects, alone or in combination. For example, the light emitted by the EMR may be replicated by the optical element at least three times (or five times, or ten times) before being emitted toward the viewer. The display system may be configured such that the light emitted by the EMR is incoupled by the incoupling element and experiences double-bounce losses (e.g., outcoupling losses due to the incoupling element) that are less than 50% (or less than 20%, or less than 10%, or less than 5%) of the incident power of the light.

[0069] The EMR may include an elemental microdisplay located at a distance from the incoupling element to the light guide of less than 30 mm (or less than 20 mm, or less than 15 mm, or less than 12 mm, or less than 10 mm, or less than 8 mm, or less than 6 mm, or less than 4 mm).

[0070] The EMR may include a microdisplay and a corresponding lens monolithically disposed and formed on or monolithically integrated with the microdisplay. For example, the lens may be molded (e.g., injection molded) on the display. Alternatively, the lens may be molded separately and attached to the microdisplay (e.g., glued with silicone or other adhesive). In some implementations, there is no air gap between the microdisplay and the lens. The EMR may include other optical elements (e.g., additional lenses).

[0071] Based on the foregoing description and drawings, many different embodiments are achievable. It is understood that describing and illustrating every combination and subcombination of these exemplary embodiments would be unduly repetitive and unclear. Accordingly, the present specification, including the drawings, shall be construed as constituting a complete written description of every combination and subcombination of the embodiments described herein, and of the manner and process of making and using them, and of any such combination or subcombination as supporting the claims.

[0072] The foregoing describes several exemplary implementations with reference to the accompanying drawings, in which embodiments of the invention are shown. However, it is understood that other implementations and configurations are possible, and the foregoing should not be construed as limiting. Rather, the disclosed implementations are provided as examples.

[0073] Terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers, and / or sections, but it will be understood that these elements, components, regions, layers, and / or sections are not intended to be limiting. These terms are merely used to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a described first element, component, region, layer, or section may be referred to as a second element, component, region, layer, or section.

[0074] Spatially relative terms, such as "beneath," "below," "lower," "under," "above," "upper," etc., may be used herein to help describe the relationship of one element or feature to another element(s) or feature(s), as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device during use or operation in addition to the orientation shown in the figures. For example, if the device in a given figure were turned upside down (rotated 180 degrees), elements described as being "below" or "below" or "beneath" the other element or feature would then be "above" or "above." Thus, the exemplary terms "below" and "under" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or to another orientation), and the spatially relative descriptors used herein may likewise be interpreted accordingly. Furthermore, when a layer is referred to as being "between" two layers, it will be understood that there may be only one layer between the two layers, or there may be one or more intervening layers.

[0075] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, it will be understood that the terms "comprise" and / or "comprising," as used herein, specify the presence of stated features, components, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, components, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as " / ."

[0076] When an element or layer is referred to as "on," "connected to," "coupled to," or "adjacent to" another element or layer, it is understood that the element or layer may be directly on, connected to, coupled to, or adjacent to the other element or layer, or that intervening elements or layers may be present. In contrast, when an element is referred to as "directly on," "directly connected to," "directly coupled to," or "closely adjacent to" another element or layer, there are no intervening elements or layers. Similarly, when light is received or provided "from" an element, the light may be received or provided directly from that element or from an intervening element. On the other hand, when light is received or provided "directly from" an element, there are no intervening elements.

[0077] Embodiments may be described herein with reference to cross-sectional illustrations that are schematic illustrations of particular embodiments (and / or intermediate structures). As such, variations from the shapes of the illustrations are expected as a result, for example, of manufacturing techniques and / or tolerances. Thus, the described embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are intended to include deviations in shape that result, for example, from manufacturing. Accordingly, the regions illustrated in the figures are schematic in nature, and their shapes are not intended to limit the actual shape of the regions on a device.

Claims

1. A microlens array projector including a plurality of elemental microlens relays (EMRs) that generate a plurality of subsets of light, Each EMR of the plurality of EMRs comprises: a microdisplay including a plurality of pixels, the microdisplay configured to generate a corresponding subset of lights among the plurality of subsets of lights, the corresponding subset of lights being associated with an image; a microlens configured to receive the corresponding subset of light from the microdisplay; A light guide and an input coupling element optically coupled to the light guide; an output coupling element optically coupled to the light guide; the microlens is configured to relay the corresponding subset of light to the input coupling element; the input coupling element is configured to incouple a subset of the plurality of lights into the light guide; the output coupling element is configured to outcouple portions of the subsets of light at multiple locations along the light guide; A wearable display system, wherein each of the plurality of subsets of lights corresponds to a corresponding one of a plurality of subsets of angles of the field of view of the image, the plurality of subsets of angles being different from one another.

2. The wearable display system of claim 1 , wherein each of the plurality of subsets of light is replicated by the light guide at least three times before being outcoupled by the output coupling element.

3. The wearable display system of claim 1 , wherein less than 10% of each of the plurality of subsets of light is outcoupled by the input coupling element.

4. The wearable display system of claim 1 , wherein the microdisplay is located less than 15 millimeters from the light guide.

5. The wearable display system of claim 1 , wherein the microlens is monolithically integrated with the microdisplay.

6. The wearable display system of claim 1 , wherein the microlens array projector has a volume of less than 0.1 cubic centimeters.

7. 10. The wearable display system of claim 1, wherein the microdisplay is configured to emit light with a brightness of at least 500,000 nits.

8. The wearable display system of claim 1 , wherein the plurality of EMRs are arranged in a non-linear pattern.

9. The wearable display system of claim 1 , wherein the plurality of EMRs are unequally spaced from one another.

10. The wearable display system of claim 1 , wherein the input coupling element includes a plurality of separate input coupling element regions.

11. a first input coupling region of the plurality of distinct input coupling element regions having a first shape; The wearable display system of claim 10 , wherein a second input coupling region of the plurality of distinct input coupling element regions has a second shape different from the first shape.

12. The wearable display system of claim 10 , wherein the plurality of distinct input coupling element regions are regularly spaced apart.

13. The wearable display system of claim 10 , wherein the plurality of distinct input coupling element regions are irregularly spaced apart.

14. the light guide has a real-world surface opposite a user-facing surface; The wearable display system of claim 1 , wherein the microlens array projector is disposed on the real-world surface.

15. The wearable display system of claim 1 , wherein the light guide is a first light guide, and the wearable display system further comprises a second light guide.

16. The wearable display system of claim 15 , wherein the second light guide is positioned flush with the first light guide.

17. The subset of the plurality of lights: red light of said image in the wavelength range of 590 to 680 nanometers (nm); green light of said image in the wavelength range of 510 to 570 nm; and blue light of said image in the wavelength range of 430 to 490 nm; The wearable display system of claim 1 , wherein:

18. The input coupling element a diffractive input coupling element, or a reflective input coupling element; The wearable display system of claim 1 , wherein:

19. The output coupling element a diffractive output coupling element, or a reflective output coupling element; The wearable display system of claim 1 , wherein:

20. A wearable display system as described in any one of claims 1 to 19, wherein the microdisplay is a microLED-based microdisplay.

21. A first elemental microlens relay (EMR) including a first microdisplay configured to generate a first subset of light associated with an image, and a first microlens configured to receive the first subset of light from the first microdisplay; a second EMR including a second microdisplay configured to generate a second subset of light associated with the image and a second microlens configured to receive the second subset of light from the second microdisplay; a third EMR including a third microdisplay configured to generate a third subset of light associated with the image and a third microlens configured to receive the third subset of light from the third microdisplay; A light guide and a first input coupling element optically coupled to the light guide, the first input coupling element configured to incouple the first subset of light into the light guide; a second input coupling element optically coupled to the light guide, the second input coupling element configured to incouple the second subset of light into the light guide; a third input coupling element optically coupled to the light guide, the third input coupling element configured to incouple the third subset of light into the light guide; an output coupling element configured to outcouple the first subset of light, the second subset of light, and the third subset of light to display the image; the first subset of lights corresponds to a first angular subset of a field of view of the image; the second subset of lights corresponds to a second angular subset of the field of view of the image that is different from the first angular subset; the third subset of lights corresponds to a third angular subset of the field of view of the image that is different from the first angular subset and the second angular subset.

22. A first elemental microlens relay (EMR) including a first microdisplay configured to generate a first subset of light associated with an image, and a first microlens configured to receive the first subset of light from the first microdisplay; a second EMR including a second microdisplay configured to generate a second subset of light associated with the image and a second microlens configured to receive the second subset of light from the second microdisplay; a third EMR including a third microdisplay configured to generate a third subset of light associated with the image and a third microlens configured to receive the third subset of light from the third microdisplay; A light guide and a first input coupling element optically coupled to the light guide, the first input coupling element configured to incouple the first subset of light into the light guide; a second input coupling element optically coupled to the light guide, the second input coupling element configured to incouple the second subset of light into the light guide; a third input coupling element optically coupled to the light guide, the third input coupling element configured to incouple the third subset of light into the light guide; an output coupling element configured to outcouple the first subset of light, the second subset of light, and the third subset of light to display the image; the first input coupling element is configured to incouple light of a first angular subset of a field of view of the image; the second input coupling element is configured to incouple light at a second angular subset of a field of view of the image that is different from the first angular subset; the third input coupling element is configured to incouple light of a third angular subset of the field of view of the image that is different from the first angular subset and the second angular subset.

23. the first subset of lights includes red light of the image; the second subset of light includes green light of the image; 23. The wearable display system of claim 21 or claim 22, wherein the third subset of lights includes blue light of the image.

24. The wearable display system of claim 21 or claim 22, wherein the output coupling element includes a plurality of outcoupling element regions.

Images