Wearable display system with nanowire led microdisplay

Abstract

A wearable display system includes one or more nanowire LED microdisplays. The nanowire micro-LED displays can be monochromatic or full color. The nanowire LEDs forming the array can have a favorably narrow angular emission profile and high light output. In cases where multiple nanowire LED microdisplays are utilized, the microdisplays can be located on different sides of an optical combiner, such as an X-cube prism, which receives light rays from the different microdisplays and outputs the light rays from the same face of the cube. The optical combiner directs the light to projection optics, which output the light to an eyepiece, which relays the light to the user's eye. The eyepiece can output the light to the user's eye with different amounts of wavefront divergence to place virtual content on different depth planes.

Description

[0001] Priority requirements

[0002] This application claims priority to U.S. Provisional Patent Application 63 / 005132, entitled “WEARABLE DISPLAY SYSTEMS WITH NANOWIRE LED MICRO-DISPLAYS”, filed April 3, 2020, the entire contents of which are incorporated herein by reference.

[0003] By incorporating via reference

[0004] This application incorporates, by reference, the entire contents of U.S. Application No. 16 / 221,359, filed December 14, 2018; U.S. Provisional Application No. 62 / 786199, filed December 28, 2018; U.S. Provisional Application No. 62 / 702,707, filed July 24, 2018; and U.S. Application No. 15 / 481,255, filed April 6, 2017. Technical Field

[0005] This disclosure relates to display systems, and more particularly to augmented and virtual reality display systems. Background Technology

[0006] Modern computing and display technologies have facilitated the development of systems for so-called “virtual reality” or “augmented reality” experiences, in which digitally reproduced images or portions thereof are presented to the user in a way that makes them appear real or 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; augmented reality or “AR” scenarios typically involve presenting digital or virtual image information as an enhancement of the visualization of the real world surrounding the user. Mixed reality or “MR” scenarios are a type of AR scenario and typically involve virtual objects integrated into and responding to the natural world. For example, an MR scenario may include AR image content that appears to be obstructed by real-world objects or is otherwise perceived as interacting with real-world objects.

[0007] refer to Figure 1The text describes an AR scene 10. A user of AR technology sees a real-world park-like setting 20 characterized by people, trees, buildings in the background, and a concrete platform 30. The user also perceives that he / she "sees" "virtual content," such as a robot 40 standing on the real-world platform 30, and a flying cartoonish avatar 50, which appears to be anthropomorphized Bumblebee. These elements 50 and 40 are "virtual" because they do not exist in the real world. Because the human visual perception system is complex, producing AR technologies that facilitate a comfortable, natural, and rich presentation of virtual image elements alongside other virtual or real-world image elements is challenging. Summary of the Invention

[0008] In some embodiments, a head-mounted display system is provided. The head-mounted display system includes: a head-mounted frame; a nanowire microLED display supported by the frame; and an eyepiece supported by the frame. The nanowire LED microdisplay is configured to output image light, and the eyepiece is configured to receive the image light from the nanowire LED microdisplay and direct the image light to the user's eyes when the frame is mounted on a user.

[0009] In some other embodiments, a head-mounted display system is provided. The head-mounted display system includes: a waveguide assembly comprising one or more waveguides; and an image projection system comprising a nanowire micro-LED array. The image projection system is configured to project an image onto the waveguide assembly. Each waveguide in the waveguide assembly includes: an input optics element configured to couple light from the image projection system into the waveguide; and an output optics element configured to couple the input light out of the waveguide. The waveguide assembly is configured to output output light having a variable wavefront divergence corresponding to a plurality of depth planes.

[0010] Additional examples of the embodiments are listed below.

[0011] Example 1. A head-mounted display system, comprising:

[0012] Headband;

[0013] A nanowire micro-LED display supported by the framework, wherein the nanowire LED micro-display is configured to output image light; and

[0014] An eyepiece supported by the frame, wherein the eyepiece is configured to receive the image light from the nanowire LED microdisplay and to direct the image light to the user's eyes when the frame is mounted on the user.

[0015] Example 2. The head-mounted display system according to Example 1, wherein the nanowire LED microdisplay is one of a plurality of nanowire LED microdisplays.

[0016] It also includes the X-cube prism,

[0017] Each of the nanowire micro-LED displays faces a different side of the X-cube prism.

[0018] The eyepiece includes a coupling optical element, and

[0019] The output side of the X-cube prism faces the light coupling element.

[0020] Example 3. The head-mounted display system according to Example 2, wherein the nanowire LED microdisplay is a monochrome nanowire LED microdisplay.

[0021] Example 4. The head-mounted display system according to Example 3, wherein the reflective surface of the X-cube prism is configured to direct light from different monochromatic nanowire LED microdisplays onto different regions of the eyepiece.

[0022] Example 5. The head-mounted display system according to Example 4, wherein the eyepiece includes a plurality of coupled optical elements having a spatial arrangement providing different optical paths from the X-cube prism to the coupled optical elements, wherein the spatial arrangement of the region corresponds to the spatial arrangement of the coupled optical elements.

[0023] Example 6. The head-mounted display system according to Example 1, wherein the eyepiece includes a plurality of waveguides forming a waveguide stack, each waveguide in the waveguide stack comprising:

[0024] A coupling optical element, configured to couple light from the nanowire LED microdisplay into the waveguide; and

[0025] The coupling optical element is configured to couple the input light out of the waveguide.

[0026] Example 7. The head-mounted display system according to Example 6, wherein the waveguide stack comprises multiple sets of waveguides, wherein each set of waveguides includes a dedicated waveguide for component colors.

[0027] Example 8. The head-mounted display system according to Example 1 further includes: a variable focal length lens element, wherein a waveguide including diffractive light-coupled-in and-coupled-out optical elements is located between a first variable focal length lens element and a second variable focal length lens element, wherein the first variable focal length lens element is configured to modify the wavefront divergence of light output from the waveguide, and wherein the second variable focal length lens element is configured to modify the wavefront divergence of light from the external world propagating through the second variable focal length lens element.

[0028] Example 9. The head-mounted display system according to Example 1 further includes: a color filter between two adjacent waveguides of the waveguide stack of the eyepiece, wherein, in an optical path extending from the microdisplay, a first waveguide in the adjacent waveguides precedes a second waveguide in the adjacent waveguides, wherein the color filter is configured to selectively absorb light corresponding to a wavelength of light coupled by the coupling optics configured to be coupled by the first waveguide in the adjacent waveguides.

[0029] Example 10. The head-mounted display system according to Example 9 further includes:

[0030] A third waveguide following the second waveguide in the adjacent waveguides in the optical path; and

[0031] Other color filters are configured to selectively absorb light corresponding to the wavelength of light coupled by the coupling optical element configured to be coupled by the second waveguide in the adjacent waveguide.

[0032] Example 11. The head-mounted display system according to Example 1, wherein the nanowire LED microdisplay comprises a spaced array of monochromatic nanowire microLEDs on a common substrate backplane.

[0033] Example 12. The head-mounted display system according to Example 11, wherein the eyepiece includes a plurality of waveguides.

[0034] The waveguides are stacked together.

[0035] Each waveguide includes a coupled optical element.

[0036] As seen in the top view, the spatial arrangement of the coupled optical elements includes different coupled optical elements located at different intervals on different waveguides.

[0037] The spatial arrangement of the monochromatic nanowire micro-LED array is matched with the spatial arrangement of the coupled optical element.

[0038] Example 13. The head-mounted display system according to Example 1, wherein the nanowire LED microdisplay comprises an array of nanowire microLEDs, wherein some of the nanowire microLEDs are configured to emit light of a component color different from that of the other nanowire microLEDs in the array of nanowire microLEDs.

[0039] Example 14. A head-mounted display system, comprising:

[0040] Waveguide components including one or more waveguides; and

[0041] An image projection system comprising an array of nanowire micro-LEDs, the image projection system being configured to project an image onto the waveguide assembly.

[0042] Each waveguide in the waveguide assembly includes:

[0043] A coupling optical element configured to couple light from the image projection system into the waveguide; and

[0044] A coupling optical element is configured to couple the coupled light out of the waveguide.

[0045] The waveguide component is configured to output coupled light with a variable wavefront divergence corresponding to multiple depth planes.

[0046] Example 15. The head-mounted display system according to Example 14, wherein each of the nanowire micro-LEDs has an angular emission profile of less than 50°.

[0047] Example 16. The head-mounted display system according to Example 15, wherein the angular emission profile is 30-45°.

[0048] Example 17. The head-mounted display system according to Example 14 further includes: projection optics configured to converge light from the nanowire LED microdisplay onto the coupling optics of the one or more waveguides.

[0049] Example 18. The head-mounted display system according to Example 14, wherein the individual light emitters in the light emitters are configured to emit light of one component color from a plurality of component colors.

[0050] The waveguide assembly includes multiple sets of waveguides.

[0051] Each set of waveguides includes a dedicated waveguide for each component color, and each set of waveguides includes a coupling optical element configured to output light with wavefront divergence corresponding to a common depth plane, wherein different sets of waveguides output light with different wavefront divergence amounts corresponding to different depth planes.

[0052] Example 19. The head-mounted display system according to Example 14 further includes: a zoom lens element, wherein the waveguide assembly is located between a first zoom lens element and a second zoom lens element, wherein the first zoom lens element is configured to modify the wavefront divergence of light output from the waveguide assembly, and wherein the second zoom lens element is configured to modify the wavefront divergence of light from the external world to the second zoom lens element.

[0053] Example 20. The head-mounted display system according to Example 14, wherein the waveguide assembly comprises a stack of waveguides.

[0054] Example 21. The head-mounted display system of claim 14, further comprising: an absorptive color filter on at least some of the main surfaces of the waveguides, wherein the absorptive color filter on the main surfaces of the waveguides is configured to absorb light of wavelengths coupled into the corresponding waveguides, wherein the waveguides are arranged in a stacked manner.

[0055] Example 22. The head-mounted display system of claim 14, wherein the waveguide assembly comprises a stack of waveguides, wherein the coupling optical element is configured to couple light, wherein the coupled light propagates substantially in a propagation direction through an associated waveguide, wherein the coupling optical element occupies a region having a width parallel to the propagation direction and a length along an axis intersecting the propagation direction, wherein the length is greater than the width. Attached Figure Description

[0056] Figure 1 This shows an augmented reality (AR) view of the user via an AR device.

[0057] Figure 2 A conventional display system for 3D images simulated for a user is shown.

[0058] Figures 3A-3C The relationship between the radius of curvature and the focal radius is shown.

[0059] Figure 4A This illustrates a representation of the accommodation-vergence response of the human visual system.

[0060] Figure 4B Examples of different accommodation and convergence states of a user's pair of eyes are shown.

[0061] Figure 4C This shows an example of a top-down view of content viewed by a user via a display system.

[0062] Figure 4D This shows another example of a top-down view of content viewed by a user via a display system.

[0063] Figure 5 This paper illustrates various aspects of a method for simulating three-dimensional images by modifying wavefront divergence.

[0064] Figure 6 An example of waveguide stacking used to output image information to a user is shown.

[0065] Figure 7 An example of an outgoing beam output from a waveguide is shown.

[0066] Figure 8 An example of stacked eyepieces is shown, where each depth plane includes an image formed using multiple different component colors.

[0067] Figure 9A A cross-sectional side view of an example of a stacked waveguide assembly is shown, each stacked waveguide including coupled optical elements.

[0068] Figure 9B It shows Figure 9A A perspective view of an example of multiple stacked waveguides.

[0069] Figure 9C It shows Figure 9A and 9B A top plan view of an example of multiple stacked waveguides.

[0070] Figure 9D A top plan view of another example of multiple stacked waveguides is shown.

[0071] Figure 9E A top plan view shows another example of a configuration for coupling optical elements.

[0072] Figure 9F An example of a wearable display system is shown.

[0073] Figure 10 An example of a wearable display system with a light projection system is shown, which has a spatial light modulator and a separate light source.

[0074] Figure 11A An example of a wearable display system with a light projection system having multiple nanowire LED microdisplays is shown.

[0075] Figure 11BA top plan view of an example of a nanowire LED microdisplay with an array of light emitters is shown.

[0076] Figure 11C This shows a structure formed by an array of nanowire LEDs. Figure 11B A cross-sectional side view of an example of a nanowire LED microdisplay.

[0077] Figure 12 Another example of a wearable display system with a light projection system is shown, which has multiple nanowire LED microdisplays and associated light reguiding structures.

[0078] Figure 13A An example of a side view of a wearable display system with a light projection system and an eyepiece is shown. The light projection system has multiple nanowire LED microdisplays, the eyepiece has a waveguide, and the waveguide has overlapping and laterally shifted light-coupled optics.

[0079] Figure 13B Another example of a wearable display system with a light projection system is shown, which has multiple nanowire LED microdisplays configured to guide light to a single light coupling region of an eyepiece.

[0080] Figure 14 An example of a wearable display system with a single nanowire LED microdisplay is shown.

[0081] Figure 15 A side view of an example eyepiece with a waveguide stack having overlapping coupled optics is shown.

[0082] Figure 16 A side view of an example of a waveguide stack with color filters for mitigating ghosting or crosstalk between waveguides is shown.

[0083] Figure 17 It shows Figure 15 and 16 An example of a top view of the eyepiece.

[0084] Figure 18 It shows Figure 15 and 16 Another example of a top view of the eyepiece.

[0085] Figure 19A A side view of an example eyepiece with a waveguide stack having overlapping and laterally shifted coupled optics is shown.

[0086] Figure 19B A color filter with the ability to mitigate ghosting or crosstalk between waveguides is shown. Figure 19A A side view of an example eyepiece.

[0087] Figure 20A It shows Figure 19A and 19B An example of a top view of the eyepiece.

[0088] Figure 20B It shows Figure 19A and 19B Another example of a top view of the eyepiece.

[0089] Figure 21 A side view of an example of re-bouncing in a waveguide is shown.

[0090] Figures 22A to 22C An example top view of an eyepiece with a coupling optics configured to reduce bounce is shown.

[0091] Figures 23A to 23C An additional example is shown, a top view of an eyepiece with a coupling optics configured to reduce bounce.

[0092] Figure 24A An example of the angular emission profile of light emitted by a single light emitter of a nanowire LED microdisplay and light captured by a projection optics is shown.

[0093] Figure 24B An example of narrowing of the angular emission profile using an array of optical collimators is shown.

[0094] Figure 25A An example side view of a conical reflector array used to guide light to a projection optics is shown.

[0095] Figure 25B An example of a side view of an asymmetric conical reflector is shown.

[0096] Figures 26A to 26C An example of the difference in the optical path of the light emitter at different positions relative to the center line of the overlying lens is shown.

[0097] Figure 27 An example side view of a single light emitter of a nanowire LED microdisplay with an overlying nanolens array is shown.

[0098] Figure 28 yes Figure 27 A perspective view of an example of a nanowire LED microdisplay.

[0099] Figure 29 It shows having Figure 28 An example of a wearable display system using full-color nanowire LED microdisplays.

[0100] Figure 30AAn example of a wearable display system with nanowire LED microdisplays and an associated array of light collimators is shown.

[0101] Figure 30B An example of a light projection system with multiple nanowire LED microdisplays, each nanowire LED microdisplay having an associated light collimator array, is shown.

[0102] Figure 30C An example of a wearable display system with multiple nanowire LED microdisplays, each nanowire LED microdisplay having an associated array of optical collimators, is shown.

[0103] Figure 31A and 31B An example of a waveguide assembly is shown, featuring a variable focus element for altering the wavefront divergence of light toward the viewer.

[0104] Figure 32A An example of a wearable display system with a light projection system is shown, which directs light of different component colors to an eyepiece without using an optical combiner to combine the different colors of light.

[0105] Figure 32B Another example of a wearable display system with a light projection system is shown, which directs light of different component colors to an eyepiece without using an optical combiner to combine the different colors of light. Detailed Implementation

[0106] Augmented reality (AR) or virtual reality (VR) systems can display virtual content to users or viewers. This content can be displayed on a head-mounted display, for example, as part of glasses, which projects image information onto the user's eyes. Additionally, in the case of an AR system, the display can also transmit light from the surrounding environment into the user's eyes to allow them to see their surroundings. As used herein, it will be understood that a "head-mounted" or "head-worn" display is a display that can be mounted on the head of a user or viewer.

[0107] Many head-mounted display systems utilize transmissive or reflective spatial light modulators to form the image presented to the user. A light source emits light, which is directed to the spatial light modulator, which then modulates the light, which is then directed to the user. A lens structure can be provided between the light source and the spatial light modulator to focus the light from the light source onto the spatial light modulator. Undesirably, the light source and associated optics can add bulk and weight to the display system. This bulk or weight can adversely affect the comfort of the head-mounted display system and its ability to be worn for extended periods.

[0108] Additionally, frame rate limitations in some head-mounted display systems can lead to viewing discomfort. Some head-mounted display systems use spatial light modulators to form images. Many spatial light modulators utilize the movement of optical elements to modulate the intensity of light output from the modulator, thereby forming an image. For example, MEMS-based spatial light modulators can use moving mirrors to modulate incident light, while LCoS-based displays can use the movement of liquid crystal molecules to modulate light. Other AR or VR systems can utilize scanning fiber optic displays, where the ends of the optical fibers physically move across an area as they output light. The light output from the fiber is synchronized with the position of the fiber ends, effectively mimicking pixels at different locations and thus forming an image. The requirement for physical movement of the optical fibers, mirrors, and liquid crystal molecules limits the speed at which individual pixels can change state, and also constrains the frame rate of displays using these optical elements.

[0109] Such limitations can lead to viewing discomfort due to factors such as motion blur and / or mismatch between the user's head orientation and the displayed image. For example, there may be a delay in detecting the user's head orientation and presenting an image that matches that orientation. During the time interval between orientation detection and image presentation to the user, the user's head may have moved. However, the presented image may correspond to a view of an object from a different orientation. Such a mismatch between the user's head orientation and the presented image can cause user discomfort (e.g., nausea).

[0110] Furthermore, due to the small cross-section of, for example, optical fibers, scanning fiber optic displays may exhibit other undesirable optical artifacts, necessitating the use of high-intensity light sources to form images with the desired apparent brightness. Suitable high-intensity light sources include lasers that output coherent light. Undesirably, the use of coherent light can lead to optical artifacts.

[0111] Micro-LED displays have been proposed as an alternative to the aforementioned spatial light modulators and scanning fiber optic displays. Micro-LED displays offer various advantages for head-mounted display systems. As an example, micro-LED displays are emission-type. The power consumption of emission-type micro-displays typically varies with the image content, making dim or sparse content require less power to display. Since AR environments can often be sparse—because users typically expect to be able to see their surroundings—emission-type micro-displays can have an average power consumption lower than other display technologies that use spatial light modulators to modulate light from a light source. Conversely, other display technologies may even use significant amounts of power for dim, sparse, or “all-off” virtual content. As another example, emission-type micro-displays can provide extremely high frame rates (which enables the use of partial resolution arrays) and can provide low levels of visually noticeable motion artifacts (e.g., motion blur). As yet another example, emission-type micro-displays may not require the type of polarization optics required by LOOS displays. Therefore, emission-type micro-displays can avoid the optical losses present in polarization optics.

[0112] Many microLED displays include planar light emitters formed on a substrate. Notably, the light emitter can have a Lambertian emission profile and can emit light on a surface area of ​​the emitter. Such microLED displays may have disadvantages in some configurations. For example, in some cases, optics can be used to narrow the emission profile to allow more emitted light to be directed to the user and thus provide higher energy efficiency. Such optics may increase the complexity and cost of display systems utilizing microLED displays. Furthermore, the reduction in light emitter size may be constrained by manufacturing and electrical considerations, and reducing the light emitter size (and the associated increase in pixel density and resolution) can be challenging. For example, some microLED-based microdisplays allow pixel pitches of approximately 2 to 3 micrometers. Even at such pixel pitches, microLED displays may still be undesirably large for use in wearable display systems to provide the desired number of pixels, especially since such systems may aim for a form factor and size similar to eyeglasses. Additionally, the brightness of the light emitter may be limited by its ability to withstand high current densities.

[0113] The various embodiments described herein utilize nanowire LED microdisplays, which typically offer the advantages of microLED displays while providing further advantages such as improved light directivity, brightness, high scalability for increased pixel density, improved color accuracy (e.g., by providing high levels of red light), and high manufacturing throughput. For example, nanowire microLED displays can maintain electro-optical conversion efficiencies down to micrometer-sized pixels, an advantage compared to planar microLED designs where efficiency can rapidly decrease to, for example, below 10-20 micrometers. Therefore, highly efficient and exceptionally high-resolution nanowire LED arrays can be formed. Furthermore, nanowire LEDs can provide built-in emission profile directivity and steering, which can be selected based on the physical design and composition of the nanowire LEDs. This simplifies the system architecture and manufacturing of display systems utilizing nanowire LEDs, as additional optics for directivity and steering can be avoided. Moreover, in some embodiments, by omitting additional optics for directivity and steering, the nanowire LED array can be filled with nanowire LEDs without being constrained by the design and grouping of nanowires to interface with additional optics. Therefore, higher nanowire densities can be achieved without changing the size of the microdisplay, and thus, higher light output can be achieved. The use of microdisplays with nanowire micro-LED arrays enables highly compact form factor viewing optics (VOA) for AR and VR wearable display systems. In some embodiments, the VOA may include a nanowire LED microdisplay and an eyepiece for relaying light from the micro-LED display to the user's eye. Advantageously, such display systems can deliver high brightness in a power-efficient manner, with high image quality metrics and color uniformity over a wide field of view.

[0114] It will be understood that nanowire LEDs can be formed from a vertically extending array of nanowires (e.g., spaced-apart pillars of material) electrically connected to two electrodes. When an electric current is applied through the nanowires, they emit light. In some embodiments, the nanowires can be considered as diodes having P and N portions.

[0115] Nanowires can also be considered three-dimensional LED devices with a larger light-emitting surface area than typical planar LEDs. For example, a 1μm x 1μm planar LED has a 1μm... 2 The active emitter area, however, as an example, is the same at 1 μm. 2 A set of 25 nanowires, each 1 μm high and 100 nm in diameter, grown within the footprint, can have a diameter of 25 x (π x 0.1 x 1) = 8 μm. 2The total active area is eight times that of a planar LED. This increase in the surface area to volume ratio of the LED “pixel” enhances the light output of the nanowire LED. This enhancement allows the nanowire LED pixel to maintain high brightness output, even for very fine pixel pitch operation. In some embodiments, the characteristics of the emitted light (wavelength, external quantum efficiency, directivity) can also be customized by selecting nanowire parameters, such as, but not limited to, material and dopants, size, geometry, structure, refractive index, etc. For example, the geometry, size, and spacing of the nanowires can be selected to provide a light emission profile with desired directivity.

[0116] Additionally, nanowires can be grouped together to form pixels. For example, common contacts or electrodes can be used for one or more nanowires to form pixels or discrete light emitters. Because each nanowire can have a diameter, for example, from 100 nm to several hundred nanometers, the pixel size and pitch can be determined by the size of the common electrode for each group of nanowires. For example, nanowires can be grouped into pixels defined by electrical contacts shared by the N and P portions of a nanowire diode group. Therefore, based on the size of the electrodes, the pixel size and pitch can be made very small. Thus, pixels with micrometer or submicrometer pitches can be realized. In some embodiments, the pixel pitch is 2 μm or less, 1 μm or less, or 800 nm or less. In some embodiments, the pixel pitch can be in the range of 200 nm to 2 μm, 200 nm to 1 μm, or 200–800 nm. As described herein, pixel pitch can refer to the distance between similar points on directly adjacent light emitters along a particular axis (e.g., the horizontal axis), where different axes have their own pixel pitches. For example, in some embodiments, the light emitter may be placed closer along the first axis than along the second axis (e.g., the orthogonal axis).

[0117] Furthermore, the various physical properties of nanowire LEDs can advantageously provide superior luminous characteristics. For example, nanowire LEDs can be formed with low mismatch dislocations and can withstand higher current densities than planar LEDs, thus allowing for higher levels of light output. Additionally, it will be understood that red-emitting nanowire LEDs can be formed by heavy indium doping of Ga nanowires. However, such doping can lead to lattice mismatch, which reduces the luminous efficiency of such nanowire LEDs. Because nanowires can be sparsely distributed across the substrate, low levels of accumulated lattice mismatch (e.g., mismatch between the InN and GaN base portions of the nanowire) can occur, which may be advantageous for forming red LEDs. Low levels of lattice mismatch provide high light output efficiency to the LED. Therefore, high levels of red light output can be achieved, which may be advantageous for forming displays with high color accuracy.

[0118] Furthermore, nanowire LEDs can be formed using semiconductor manufacturing processes to create nanowires and associated electrodes, where, for example, indium doping is utilized to provide the desired electronic bandgap tuning for the desired light output color. Moreover, forming nanowire LEDs on a semiconductor substrate allows for process compatibility with CMOS backplanes (e.g., via wafer-to-wafer bonding or flip-chip bonding). It will be understood that semiconductor manufacturing processes can provide high throughput in high-volume manufacturing results.

[0119] In some embodiments, one or more nanowire LED microdisplays may be used to form images for a head-mounted display system. The light containing image information used to form these images may be referred to as image light. It will be understood that image light can vary in, for example, wavelength, intensity, polarization, etc. The nanowire LED microdisplay outputs image light to an eyepiece, which then relays the light to the user's eye.

[0120] In some embodiments, one or more nanowire LED microdisplays can be utilized and positioned on different sides of an optical combiner (e.g., an X-cube prism or a dichroic X-cube). The X-cube prism receives light from different microdisplays on different faces of the cube and outputs light from the different microdisplays to the other face of the cube. Light from all the different microdisplays can be output from the same output face of the cube. The output light can be directed to a projection optics configured to converge or focus the image light onto an eyepiece.

[0121] In some embodiments, one or more nanowire LED microdisplays include a monochrome microdisplay configured to output light of a single component color. The various component colors are combined to form a panchromatic image. In some embodiments, one or more of the nanowire LED microdisplays may have subpixels configured to emit two or more, but not all, component colors of light used by the display system. For example, a single nanowire LED microdisplay may have subpixels emitting blue and green light, while individual nanowire LED microdisplays on different faces of an X-cube may have pixels configured to emit red light. In some embodiments, each of the one or more microdisplays is a panchromatic display, comprising, for example, a pixel formed by a plurality of subpixels configured to emit light of different component colors. Advantageously, combining the light from multiple panchromatic microdisplays can increase the display's brightness and dynamic range.

[0122] It will be understood that nanowire LED microdisplays may include arrays of light emitters. Preferably, as discussed herein, the composition, geometry, size, and spacing of the nanowires forming the nanowire LEDs are selected to provide a desired light emission profile with a desired angular extension.

[0123] However, in some embodiments, nanowire LEDs can emit light with an angular emission profile larger than desired. Undesirably, such an angular emission profile can "waste" light, as only a small fraction of the emitted light may end up incident on the eyepiece. In some embodiments, an optical collimator can be used to narrow the angular emission profile of the light emitted by the nanowire LED light emitter. As used herein, an optical collimator is an optical structure that narrows the angular emission profile of incident light; that is, the optical collimator receives light from an associated light emitter having a relatively wide initial angular emission profile and outputs light with an angular emission profile narrower than the wide initial angular emission profile. In some embodiments, the light ray exiting the optical collimator is more parallel than the light received by the optical collimator before it passes through and exits the collimator. Examples of optical collimators include microlenses, nanolenses, reflective traps, metasurfaces, and liquid crystal gratings. In some embodiments, the optical collimator can be configured to deflect light to ultimately converge on different laterally shifted optically coupled optical elements. In some embodiments, each light emitter has a dedicated optical collimator. The optical collimator is preferably positioned directly adjacent to or in contact with the optical emitter to capture most of the light emitted by the associated optical emitter.

[0124] In some embodiments, a single nanowire LED microdisplay can be used to output light to an eyepiece. For example, a single nanowire LED microdisplay can be a panchromatic display comprising light emitters that emit light of different component colors. In some embodiments, the light emitters can be grouped in a common area, wherein each group comprises a light emitter that emits light of each component color. In such embodiments, each group of light emitters can share a common microlens. Advantageously, as discussed herein, different colors of light from different light emitters take different paths through the microlenses, which can manifest as different component colors of light incident on different coupled optical elements of the eyepiece.

[0125] In some embodiments, a panchromatic microdisplay may include light emitters in repeating groups of the same component color. For example, the microdisplay may include rows of light emitters, wherein the light emitters in each individual row are configured to emit light of the same color. Thus, different rows may emit light of different component colors. Additionally, the microdisplay may have an associated array of collimators configured to direct light to a desired location on the eyepiece, for example, to an associated coupling optics. Advantageously, while the individual light emitters of such a panchromatic microdisplay may not be positioned to form a high-quality panchromatic image, as directly observed on the microdisplay, a lens array appropriately directs light from the light emitters to the eyepiece, which combines the monochromatic images formed by light emitters of different colors, thereby forming a high-quality panchromatic image.

[0126] In some embodiments, an eyepiece receiving image light from a nanowire LED microdisplay may include a waveguide assembly. The waveguide region of the waveguide assembly to which the image light is incident may include a coupling optics element that couples the incident image light such that the light propagates through the waveguide with total internal reflection (TIR). In some embodiments, the waveguide assembly may include a waveguide stack, wherein each waveguide has an associated coupling optics element. Different coupling optics elements may be configured to couple different colors of light, such that different waveguides may be configured to propagate different colors of light therein. The waveguide may include a decoupling optics element that couples out the light propagating therein, such that the decoupling light propagates toward the user's eye. In some embodiments, the waveguide assembly may include a single waveguide having an associated coupling optics element configured to couple multiple different component colors of light.

[0127] In some embodiments, as seen from the projection optics, the coupling optics are laterally shifted. Different coupling optics can be configured to couple different colors of light. Preferably, different colors of image light take different paths to reach the eyepiece and, therefore, are incident on different corresponding coupling optics.

[0128] In some embodiments, other types of eyepieces or optics may be used for relaying image light to a user's eye. For example, as discussed herein, an eyepiece may include one or more waveguides in which image light propagates in TIR. As another example, an eyepiece may include a basin assembler that includes a semi-transparent mirror that directs image light to the viewer and allows viewing of the surrounding environment.

[0129] In some embodiments, the eyepiece may be configured to selectively output light with different wavefront divergence to provide virtual content at one or more virtual depth planes (also referred to herein as “depth planes”) perceived to be at different distances from the user. For example, the eyepiece may include one or more waveguides, each waveguide having an outgoing optical element with different refractive powers to output light with different wavefront divergence. In some embodiments, a zoom element may be provided between the eyepiece and the user’s eye. The zoom element may be configured to dynamically change the refractive power to provide the desired wavefront divergence for a particular virtual content. In some embodiments, as an alternative to or supplement to the waveguide optical structure for providing refractive power, the display system may also include one or more lenses that provide or additionally provide refractive power.

[0130] Reference will now be made to the accompanying drawings, in which similar reference numerals refer to similar parts throughout. Unless otherwise specified, the drawings are schematic and not necessarily drawn to scale.

[0131] Figure 2A conventional display system for simulating 3D images for a user is illustrated. It will be understood that the user's eyes are separated, and when viewing a real object in space, each eye will have a slightly different view of the object, forming an image of the object at a different location on the retina of each eye. This can be called binocular parallax and can be utilized by the human visual system to provide depth perception. The conventional display system simulates binocular parallax by presenting two different images 190 and 200 with slightly different views (one for each eye, 210 and 220) of the same virtual object, corresponding to the view of the virtual object that each eye will see, which is a virtual representation of the real object located at the desired depth. These images provide binocular cues, which the user's visual system can interpret to obtain depth perception.

[0132] Continue to refer to Figure 2 Images 190 and 200 are separated from eyes 210 and 220 by a distance 230 on the z-axis. The z-axis is parallel to the observer's optical axis, and their eyes are focused on an object at optical infinity directly in front of the observer. Images 190 and 200 are flat and at a fixed distance from eyes 210 and 220. Based on slightly different views of the virtual object in the images presented to eyes 210 and 220 respectively, the eyes can naturally rotate so that the image of the object falls on a corresponding point on the retina of each eye, maintaining a single binocular vision. This rotation allows the gaze of each eye 210 and 220 to converge on a point in space where the virtual object is perceived to exist. As a result, providing three-dimensional imagery typically involves providing binocular cues that can manipulate the convergence of the user's eyes 210 and 220, and the human visual system interprets these binocular cues to provide depth perception.

[0133] However, generating a realistic and comfortable sense of depth is challenging. It will be understood that light from objects at different distances from the eye has wavefronts with different divergence. Figures 3A-3C This illustrates the relationship between distance and the divergence of light. The distances between the object and the eye 210 are represented by R1, R2, and R3 in decreasing order. (As shown in...) Figures 3A-3C As shown, the light rays become more divergent as the distance to the object decreases. Conversely, the light rays become more collimated as the distance increases. In other words, the light field generated by a point (the object or a portion of the object) can be said to have a spherical wavefront curvature, which is a function of how far that point is from the user's eye. The curvature increases as the distance between the object and the eye 210 decreases. Although in Figures 3A-3C For clarity, only a single eye 210 is shown in the other figures in this article. Discussion of eye 210 can be applied to both eyes 210 and 220 of the observer.

[0134] Continue to refer to Figures 3A-3C Light from an object viewed by an observer's eye can have varying degrees of wavefront divergence. Due to these differences in wavefront divergence, the light can be focused differently by the eye's lens, which may in turn require the lens to take on different shapes to form a focused image on the retina. In the absence of a focused image on the retina, the resulting retinal blur acts as a cue for accommodation, causing a change in the shape of the eye's lens until a focused image is formed on the retina. For example, a cue for accommodation can trigger relaxation or contraction of the ciliary muscles surrounding the lens, thereby modulating the force applied to the suspensory ligaments that hold the lens in place, thus causing a change in the shape of the lens until the retinal blur of the viewed object is eliminated or minimized, thereby forming a focused image of the viewed object on the retina (e.g., the fovea). The process of the eye's lens changing shape can be called accommodation, and the shape of the eye's lens required to form a focused image of the viewed object on the retina (e.g., the fovea) can be called the state of accommodation.

[0135] Now for reference Figure 4A This illustrates a representation of the accommodation-convergence response of the human visual system. Eye movements to gaze at an object cause the eye to receive light from the object, where the light forms an image on each of the retina of the eye. The presence of retinal blurring in the image formed on the retina provides a cue for accommodation, and the relative position of the image on the retina provides a cue for convergence. The cue for accommodation causes accommodation to occur, resulting in each lens of the eye exhibiting a specific state of accommodation that forms a focused image of the object on the retina of the eye (e.g., the fovea). On the other hand, the cue for convergence causes convergence movement (rotation of the eye) to occur, such that the image formed on each retina of each eye is located at the corresponding retinal point that maintains single binocular vision. At these positions, it can be said that the eye is in a specific state of convergence. (Continue to reference) Figure 4A Accommodation can be understood as the process by which the eye achieves a specific state of accommodation, and convergence can be understood as the process by which the eye achieves a specific state of convergence. For example... Figure 4A As shown, the eye's accommodation and convergence states can change if the user gazes at another object. For example, the accommodation state can change if the user gazes at a new object at a different depth on the z-axis.

[0136] Unrestricted by theory, it is believed that an observer can perceive an object as "three-dimensional" due to a combination of convergence and accommodation. As mentioned above, the convergence of the two eyes relative to each other (e.g., eye rotation causing the pupils to move toward or away from each other to converge the line of sight to an object) is closely related to the accommodation of the eye's lens. Under normal circumstances, changing the shape of the eye's lens to shift focus from one object to another at a different distance will automatically cause a matching change in convergence at the same distance under a relationship known as "accommodation-convergence reflex." Similarly, under normal circumstances, changes in convergence will trigger a matching change in the shape of the lens.

[0137] Now for reference Figure 4B Examples of different accommodation and convergence states of the eye are shown. Eye pair 222a gazes at an object at optical infinity, while eye pair 222b gazes at an object 221 less than optical infinity. Notably, the convergence state of each pair of eyes is different, with eye pair 222a pointing straight ahead, while eye pair 222 converges on object 221. The accommodation state of the eyes forming each pair of eyes 222a and 222b can also be different, as represented by the different shapes of the lenses 210a and 220a.

[0138] Unfortunately, many users of conventional "3-D" display systems find these systems uncomfortable or completely lacking in depth perception due to the mismatch between accommodation and convergence states in these displays. As mentioned above, many stereoscopic or "3-D" display systems display scenes by providing slightly different images to each eye. Such systems are uncomfortable for many observers because they merely offer different presentations of the scene and cause changes in the eyes' convergence state, but not corresponding changes in the eyes' accommodation state. However, the image is displayed on a display at a fixed distance from the eyes, allowing the eyes to view all image information in a single accommodation state. This arrangement violates the "accommodation-convergence reflection" by causing changes in convergence without a matching change in accommodation. This mismatch is considered to cause discomfort to the observer. Display systems that provide a better match between accommodation and convergence can create more realistic and comfortable 3D image simulations.

[0139] Unrestricted by theory, the human eye is believed to typically interpret a finite number of depth planes to provide depth perception. Therefore, highly reliable simulations of perceived depth can be achieved by providing the eye with different presentations of images corresponding to each of these finite number of depth planes. In some embodiments, the different presentations can provide cues for convergence and matching cues for accommodation, thus providing physiologically correct accommodation-convergence matching.

[0140] Continue to refer to Figure 4BTwo depth planes 240 are shown, corresponding to different distances in space from the eyes 210, 220. For a given depth plane 240, convergence cues can be provided by displaying images with appropriately different perspectives for each eye 210, 220. Furthermore, for a given depth plane 240, the light forming the image provided to each eye 210, 220 can have wavefront divergence corresponding to the light field generated by a point at a distance from that depth plane 240.

[0141] In the illustrated embodiment, the depth plane 240 containing point 221 is 1 m along the z-axis. As used herein, the distance or depth along the z-axis can be measured from a zero point located at the exit pupil of the user's eye. Therefore, on the optical axis of eyes pointing towards optical infinity, the depth plane 240 at a depth of 1 m corresponds to a distance of 1 m from the exit pupil of the user's eye. As an approximation, the depth or distance along the z-axis can be measured from a display (e.g., from the surface of the waveguide) in front of the user's eyes, plus the value of the distance between the device and the exit pupil of the user's eye. This value can be called the eye relief and corresponds to the distance between the exit pupil of the user's eye and the display worn by the user in front of their eyes. In practice, the value of the eye relief can be a standardized value typically used for all observers. For example, it can be assumed that the eye relief is 20 mm, and the depth plane with a depth of 1 m is located at a distance of 980 mm in front of the display.

[0142] Now for reference Figure 4C and 4D Examples of matched and mismatched convergence distances are shown, respectively. Figure 4C As shown, the display system can provide an image of a virtual object to each eye 210, 220. The image allows the eyes 210, 220 to perceive a convergent state where the eyes converge at point 15 on the depth plane 240. Furthermore, the image can be formed by light having a wavefront curvature corresponding to the real object at that depth plane 240. As a result, the eyes 210, 220 perceive an accommodative state where the image is focused on the retina of those eyes. Therefore, the user can perceive the virtual object at point 15 on the depth plane 240.

[0143] It will be understood that each of the accommodation and convergence states of eyes 210 and 220 is associated with a specific distance on the z-axis. For example, an object at a specific distance from eyes 210 and 220 causes those eyes to exhibit a specific accommodation state based on the distance to that object. The distance associated with a specific accommodation state can be called the accommodation distance A. d Similarly, there exists a specific convergence distance V associated with the eyes in a particular convergence state or with respect to each other. dWhen the accommodation distance and convergence distance are matched, it can be said that the relationship between accommodation and convergence is physiologically correct. This is considered the most comfortable scenario for the viewer.

[0144] However, in stereoscopic displays, the accommodation distance and convergence distance may not always match. For example, as Figure 4D As shown, the images displayed to eyes 210, 220 can be displayed with wavefront divergence corresponding to depth plane 240, and eyes 210, 220 can present a specific accommodation state with points 15a, 15b in focus on that depth plane. However, the images displayed to eyes 210, 220 may provide cues for convergence of eyes 210, 220 to point 15, which is not located on depth plane 240. As a result, in some embodiments, the accommodation distance corresponds to the distance from the exit pupil of eyes 210, 220 to depth plane 240, while the convergence distance corresponds to a greater distance from the exit pupil of eyes 210, 220 to point 15. Accommodation distance and convergence distance are different. Therefore, there is an accommodation-convergence mismatch. This mismatch is considered undesirable and may cause discomfort to the user. It will be understood that the mismatch corresponds to distance (e.g., V d -A d And it can be characterized using diopter.

[0145] In some embodiments, it will be understood that reference points other than the exit pupils of eyes 210, 220 can be used to determine the distances used to determine accommodation-convergence mismatch, provided that the same reference points are used for both accommodation and convergence distances. For example, distances can be measured from the cornea to the depth plane, from the retina to the depth plane, from the eyepiece (e.g., the waveguide of a display device) to the depth plane, etc.

[0146] Not limited by theory, it is believed that users can still perceive accommodation-convergence mismatches of up to about 0.25 diopters, up to about 0.33 diopters, and up to about 0.5 diopters as physiologically correct, without significant discomfort caused by the mismatch itself. In some embodiments, the display systems disclosed herein (e.g., Figure 6 The display system 250 presents an image to an observer with an accommodation-verb mismatch of about 0.5 diopters or less. In some other embodiments, the accommodation-verb mismatch of the image provided by the display system is about 0.33 diopters or less. In other embodiments, the accommodation-verb mismatch of the image provided by the display system is about 0.25 diopters or less, including about 0.1 diopters or less.

[0147] Figure 5A method for simulating a three-dimensional image by modifying wavefront divergence is illustrated. The display system includes a waveguide 270 configured to receive light 770 encoded using image information and output that light to a user's eye 210. The waveguide 270 can output light 650 having a defined amount of wavefront divergence corresponding to the wavefront divergence of the light field generated by points on a desired depth plane 240. In some embodiments, the same amount of wavefront divergence is provided for all objects presented on that depth plane. Additionally, it will be explained that image information from a similar waveguide can be provided to the user's other eye.

[0148] In some embodiments, a single waveguide may be configured to output light with a predetermined amount of wavefront divergence corresponding to a single or finite number of depth planes and / or the waveguide may be configured to output light within a finite wavelength range. Therefore, in some embodiments, multiple waveguides or waveguide stacks may be utilized to provide different amounts of wavefront divergence for different depth planes and / or output light with different wavelength ranges. As used herein, it will be understood that the depth planes may be planar or may follow the contours of a curved surface.

[0149] Figure 6 An example of a waveguide stack for outputting image information to a user is shown. The display system 250 includes a stack of waveguides or a stacked waveguide assembly 260, which can be used to provide three-dimensional perception to the eye / brain using multiple waveguides 270, 280, 290, 300, 310. It will be understood that in some embodiments, the display system 250 can be considered a light field display. Additionally, the waveguide assembly 260 can also be referred to as an eyepiece.

[0150] In some embodiments, the display system 250 may be configured to provide a substantially continuous cue regarding convergence and a plurality of discrete cues regarding accommodation. The cue regarding convergence may be provided by displaying a different image to each of the user's eyes, and the cue regarding accommodation may be provided by outputting light forming the image with a selectable discrete amount of wavefront divergence. In other words, the display system 250 may be configured to output light with variable levels of wavefront divergence. In some embodiments, each discrete level of wavefront divergence corresponds to a specific depth plane and may be provided by a particular one of waveguides 270, 280, 290, 300, 310.

[0151] Continue to refer to Figure 6Waveguide assembly 260 may further include multiple features 320, 330, 340, 350 between waveguides. In some embodiments, features 320, 330, 340, 350 may be one or more lenses. Waveguides 270, 280, 290, 300, 310 and / or multiple lenses 320, 330, 340, 350 may be configured to send image information to the eye at different levels of wavefront curvature or light divergence. Each waveguide level may be associated with a specific depth plane and may be configured to output image information corresponding to that depth plane. Image injection devices 360, 370, 380, 390, 400 may serve as light sources for the waveguides and may be used to inject image information into waveguides 270, 280, 290, 300, 310, as described herein, wherein each waveguide may be configured to distribute incident light across each respective waveguide for output toward the eye 210. Light exits the output surfaces 410, 420, 430, 440, and 450 of the image injection devices 360, 370, 380, 390, and 400 and is injected into the corresponding input surfaces 460, 470, 480, 490, and 500 of the waveguides 270, 280, 290, 300, and 310. In some embodiments, each of the input surfaces 460, 470, 480, 490, and 500 may be an edge of the corresponding waveguide or a portion of the main surface of the corresponding waveguide (i.e., a surface of the waveguide that directly faces the world 510 or the observer's eye 210). In some embodiments, a single beam of light (e.g., a collimated beam) may be injected into each waveguide to output the entire field of a cloned collimated beam directed toward the eye 210 at a specific angle (and divergence) corresponding to the depth plane associated with the particular waveguide. In some embodiments, a single one of the image injection devices 360, 370, 380, 390, 400 may be associated with a plurality of (e.g., three) waveguides 270, 280, 290, 300, 310 and inject light into the plurality of (e.g., three) waveguides 270, 280, 290, 300, 310.

[0152] In some embodiments, the image injection devices 360, 370, 380, 390, and 400 are discrete displays, each generating image information for injection into corresponding waveguides 270, 280, 290, 300, and 310, respectively. In some other embodiments, the image injection devices 360, 370, 380, 390, and 400 are outputs of a single multiplexed display, the output of which may, for example, deliver image information to each of the image injection devices 360, 370, 380, 390, and 400 via one or more optical conduits (such as fiber optic cables). It will be understood that the image information provided by the image injection devices 360, 370, 380, 390, and 400 may include light of different wavelengths or colors (e.g., different component colors, as discussed herein).

[0153] In some embodiments, light injected into waveguides 270, 280, 290, 300, 310 is provided by a light projector system 520, which includes an optical module 530 that may include a light emitter, such as a light-emitting diode (LED). Light from the optical module 530 may be directed via a beam splitter 550 to an optical modulator 540 (e.g., a spatial light modulator) and modified by the optical modulator 540. The optical modulator 540 may be configured to change the perceived intensity of light injected into waveguides 270, 280, 290, 300, 310 to encode light with image information. Examples of spatial light modulators include liquid crystal displays (LCDs), including liquid crystal on silicon (LCOS) displays. It will be understood that image injection devices 360, 370, 380, 390, and 400 are schematically shown, and in some embodiments, these image injection devices may represent different optical paths and locations in a shared projection system configured to output light into associated waveguides in waveguides 270, 280, 290, 300, and 310. In some embodiments, the waveguide of waveguide assembly 260 may function as an ideal lens while relaying the light injected into the waveguide to the user's eye. In this concept, the object may be a spatial light modulator 540, and the image may be an image on the depth plane.

[0154] In some embodiments, the display system 250 may be a scanning fiber optic display comprising one or more scanning fibers configured to project light in various patterns (e.g., raster scanning, spiral scanning, Lissajous patterns, etc.) into one or more waveguides 270, 280, 290, 300, 310 and ultimately to an observer's eye 310. In some embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 may schematically represent a single scanning fiber or a bundle of scanning fibers configured to inject light into one or more waveguides 270, 280, 290, 300, 310. In some other embodiments, the illustrated image injection devices 360, 370, 380, 390, 400 may schematically represent multiple scanning fibers or multiple bundles of scanning fibers, each configured to inject light into an associated one of the waveguides 270, 280, 290, 300, 310. It will be understood that one or more optical fibers can be configured to transmit light from optical module 530 to one or more waveguides 270, 280, 290, 300, 310. It will be understood that one or more intermediate optical structures may be provided between the scanning fiber or the fiber and one or more waveguides 270, 280, 290, 300, 310 to, for example, redirect light leaving the scanning fiber to one or more waveguides 270, 280, 290, 300, 310.

[0155] Controller 560 controls the operation of one or more of the stacked waveguide assemblies 260, including the operation of image injection devices 360, 370, 380, 390, 400, light source 530, and optical modulator 540. In some embodiments, controller 560 is part of local data processing module 140. Controller 560 includes timing and provided programming (e.g., instructions in a non-transient medium) of image information modulated to waveguides 270, 280, 290, 300, 310 according to, for example, any of the various schemes disclosed herein. In some embodiments, the controller may be a single integrator or a distributed system connected by wired or wireless communication channels. In some embodiments, controller 560 may be processing module 140 or 150. Figure 9F Part of ).

[0156] Continue to refer to Figure 6Waveguides 270, 280, 290, 300, and 310 can be configured to propagate light within each respective waveguide via total internal reflection (TIR). Waveguides 270, 280, 290, 300, and 310 can each be planar or have another shape (e.g., curved), having a primary top surface and a primary bottom surface, and an edge extending between those primary top and bottom surfaces. In the illustrated configuration, waveguides 270, 280, 290, 300, and 310 can each include coupling optics 570, 580, 590, 600, and 610, which are configured to extract light from the waveguide by redirecting light propagating within each respective waveguide to output image information to eye 210. The extracted light can also be referred to as the coupled light, and the coupled optics light can also be referred to as the light extraction optics. The extracted light beam can be output by striking the light extraction optics at the location of the light propagating in the waveguide. The coupling optics 570, 580, 590, 600, and 610 can be, for example, gratings including diffractive optical features, as further discussed herein. Although illustrated on the bottom main surface of waveguides 270, 280, 290, 300, and 310 for ease of description and clarity of the figures, in some embodiments, the coupling optics 570, 580, 590, 600, and 610 can be disposed on the top and / or bottom main surfaces, and / or can be disposed directly within the volume of waveguides 270, 280, 290, 300, and 310, as further discussed herein. In some embodiments, the coupling optics 570, 580, 590, 600, and 610 can be formed in a material layer attached to a transparent substrate to form waveguides 270, 280, 290, 300, and 310. In some other embodiments, waveguides 270, 280, 290, 300, and 310 may be monolithic materials, and coupled optical elements 570, 580, 590, 600, and 610 may be formed on the surface and / or inside the monolithic material.

[0157] Continue to refer to Figure 6As discussed herein, each waveguide 270, 280, 290, 300, 310 is configured to output light to form an image corresponding to a specific depth plane. For example, the waveguide 270 closest to the eye can be configured to deliver collimated light (injected into such a waveguide 270) to the eye 210. The collimated light may represent the optical infinity focal plane. The next upper waveguide 280 can be configured to emit collimated light that passes through a first lens 350 (e.g., a negative lens) before reaching the eye 210; such a first lens 350 can be configured to produce a slight convex wavefront curvature, such that the eye / brain interprets the light from the next upper waveguide 280 as coming from a first focal plane that is closer inward from optical infinity toward the eye 210. Similarly, the third upper waveguide 290 causes its output light to pass through the first lens 350 and the second lens 340 before reaching the eye 210; the combined optical power of the first lens 350 and the second lens 340 can be configured to produce another increase in wavefront curvature, such that the eye / brain interprets the light from the third waveguide 290 as coming from a second focal plane that is closer to the person than the light from the next upper waveguide 280 from optical infinity.

[0158] The other waveguide layers 300, 310 and lenses 330, 320 are similarly configured, wherein the highest waveguide 310 in the stack sends its output through all the lenses between itself and the eye to represent the total optical power of the focal plane closest to the person. To compensate for the stacking of lenses 320, 330, 340, 350 when viewing / interpreting light from the world 510 on the other side of the stacked waveguide assembly 260, a compensation lens layer 620 can be disposed on top of the stack to compensate for the total optical power of the lens stack 320, 330, 340, 350 below. Such a configuration provides as many focal planes as are available waveguide / lens pairs. Both the decoupled optics of the waveguides and the focusing aspects of the lenses can be static (i.e., non-dynamic or electrically active). In some alternative embodiments, one or both may be dynamically active using electrically active features.

[0159] In some embodiments, two or more of waveguides 270, 280, 290, 300, and 310 may have the same associated depth plane. For example, multiple waveguides 270, 280, 290, 300, and 310 may be configured to output image sets to the same depth plane, or multiple subsets of waveguides 270, 280, 290, 300, and 310 may be configured to output image sets to the same multiple depth planes, wherein there is one set for each depth plane. This can provide the advantage of forming stitched images to provide an extended field of view at those depth planes.

[0160] Continue to refer to Figure 6The coupling optics 570, 580, 590, 600, and 610 can be configured to redirect light outside their respective waveguides and output the light with an appropriate amount of divergence or collimation for a specific depth plane associated with the waveguide. Thus, waveguides with different associated depth planes can have different configurations of the coupling optics 570, 580, 590, 600, and 610, which output light with different amounts of divergence depending on the associated depth plane. In some embodiments, the light extraction optics 570, 580, 590, 600, and 610 can be volumetric or surface features that can be configured to output light at a specific angle. For example, the light extraction optics 570, 580, 590, 600, and 610 can be volumetric holograms, surface holograms, and / or diffraction gratings. In some embodiments, features 320, 330, 340, and 350 may not be lenses; instead, they can simply be spacers (e.g., cladding and / or structures for forming gaps).

[0161] In some embodiments, the coupling optical elements 570, 580, 590, 600, and 610 are diffraction features that form a diffraction pattern, or "diffraction optical elements" (also referred to herein as "DOEs"). Preferably, the DOE has a sufficiently low diffraction efficiency such that only a portion of the beam is deflected toward the eye 210 at each intersection of the DOE, while the remainder continues to move through the waveguide via TIR. The light carrying image information is thus split into many associated outgoing beams exiting the waveguide at many locations, and the result is a fairly uniform pattern of outgoing emission toward the eye 210 for that particular collimated beam bouncing throughout the waveguide.

[0162] In some embodiments, one or more DOEs can switch between an "on" state in which they actively diffract and an "off" state in which they do not significantly diffract. For example, a switchable DOE may include a polymer-dispersed liquid crystal layer, wherein the droplets comprise a diffraction pattern in a host medium, and the refractive index of the droplets may be switched to substantially match the refractive index of the host material (in which case the pattern does not significantly diffract incident light) or the droplets may be switched to a refractive index that does not match the refractive index of the host medium (in which case the pattern actively diffracts incident light).

[0163] In some embodiments, camera assembly 630 (e.g., a digital camera, including visible light and infrared light cameras) may be provided to acquire images of eye 210 and / or tissues surrounding eye 210, for example, to detect user input and / or monitor the user's physiological state. As used herein, the camera can be any image acquisition device. In some embodiments, camera assembly 630 may include an image acquisition device and a light source that projects light (e.g., infrared light) onto the eye, which can then be reflected by the eye and detected by the image acquisition device. In some embodiments, camera assembly 630 may be attached to a frame or support structure 80 (…). Figure 9F It can also be in electrical communication with processing modules 140 and / or 150, which can process image information from camera assembly 630. In some embodiments, one camera assembly 630 can be used for each eye to monitor each eye individually.

[0164] Now for reference Figure 7 An example of an output beam from a waveguide is shown. A single waveguide is illustrated, but it will be understood that in the case where waveguide assembly 260 comprises multiple waveguides, waveguide assembly 260 ( Figure 6 Other waveguides in the waveguide can operate similarly. Light 640 is injected into waveguide 270 at input surface 460 and propagates within waveguide 270 via TIR. At the point where light 640 is incident on DOE 570, a portion of the light exits the waveguide as an outgoing beam 650. The outgoing beam 650 is illustrated as substantially parallel, but as discussed herein, it can also be redirected to propagate at an angle to eye 210 (e.g., forming a diverging outgoing beam), depending on the depth plane associated with waveguide 270. It will be understood that a substantially parallel outgoing beam can indicate a waveguide with a coupling optics element that couples the light to form an image that appears to be set on a depth plane at a large distance (e.g., optical infinity) from eye 210. Other waveguides or other sets of coupled optical elements can output a more divergent beam pattern that would require the eye 210 to adjust to a closer distance to focus on the retina and be interpreted by the brain as light coming from a distance closer to the eye 210 than optical infinity.

[0165] In some embodiments, a panchromatic image can be formed at each depth plane by images of each of the overlapping component colors (e.g., three or more component colors). Figure 8An example of a stacked waveguide assembly, where each depth plane includes an image formed using multiple different component colors, is illustrated. The illustrated embodiment shows depth planes 240a–240f, although more or fewer depths are also anticipated. Each depth plane may have three or more component color images associated with it, including: a first image of a first color G; a second image of a second color R; and a third image of a third color B. Different depth planes are indicated in the figures by different numbers following the letters G, R, and B for diopter (dpt). By way of example only, the number following each of these letters indicates diopter (1 / m), or the inverse distance of the depth plane from the observer, and each box in the figures represents a single component color image. In some embodiments, the exact positioning of the depth planes for different color components can vary to account for differences in eye focusing on different wavelengths of light. For example, different component color images for a given depth plane may be placed on depth planes corresponding to different distances from the user. Such an arrangement can increase visual sensitivity and user comfort and / or can reduce chromatic aberration.

[0166] In some embodiments, light of each component color can be output by a single dedicated waveguide, and therefore, each depth plane can have multiple waveguides associated with it. In such embodiments, each box in the figure including the letters G, R, or B can be understood to represent a single waveguide, and each depth plane can provide three waveguides, wherein each depth plane provides three component color images. Although the waveguides associated with each depth plane are shown as adjacent to each other in the figures, it will be understood that in a physical device, the waveguides can all be arranged in a stack, wherein each layer has one waveguide. In some other embodiments, multiple component colors can be output by the same waveguide, such that, for example, each depth plane can provide only a single waveguide.

[0167] Continue to refer to Figure 8 In some embodiments, G is green, R is red, and B is blue. In some other embodiments, other colors associated with other wavelengths of light (including magenta and cyan) may be used or may replace one or more of red, green, or blue.

[0168] It will be understood that references to a given color of light throughout this disclosure will be interpreted as encompassing light of one or more wavelengths within a range of wavelengths perceived by an observer to have that given color. For example, red light may include light of one or more wavelengths in the range of approximately 620–780 nm, green light may include light of one or more wavelengths in the range of approximately 492–577 nm, and blue light may include light of one or more wavelengths in the range of approximately 435–493 nm.

[0169] In some embodiments, the light source 530 ( Figure 6 The display 250 can be configured to emit light at one or more wavelengths outside the observer's visual perception range, such as infrared and / or ultraviolet wavelengths. Additionally, the waveguide coupling-in, coupling-out, and other light redirection structures of the display 250 can be configured to direct the light toward the user's eye 210 and emit it outside the display, for example, for imaging and / or user stimulation applications.

[0170] Now for reference Figure 9A In some embodiments, light incident on a waveguide may need to be redirected to couple the light into the waveguide. Coupling optics can be used to redirect the light and couple it into its corresponding waveguide. Figure 9A The illustration shows a cross-sectional side view of an example of multiple stacked waveguides or stacked waveguide sets 660, each including coupled optical elements. Each waveguide can be configured to output light of one or more different wavelengths or one or more different wavelength ranges. It will be understood that stack 660 can correspond to stack 260 (…). Figure 6 Furthermore, the waveguides of the illustrated stack 660 may correspond to a portion of a plurality of waveguides 270, 280, 290, 300, 310, except that light from one or more of the image injection devices 360, 370, 380, 390, 400 is injected into the waveguides from the desired light redirection to the coupled location.

[0171] The illustrated stacked waveguide assembly 660 includes waveguides 670, 680, and 690. Each waveguide includes an associated coupling optical element (which may also be referred to as a light input region on the waveguide), wherein, for example, a coupling optical element 700 is disposed on the main surface (e.g., the upper main surface) of waveguide 670, a coupling optical element 710 is disposed on the main surface (e.g., the upper main surface) of waveguide 680, and a coupling optical element 720 is disposed on the main surface (e.g., the upper main surface) of waveguide 690. In some embodiments, one or more of the coupling optical elements 700, 710, and 720 may be disposed on the bottom main surface of the respective waveguide 670, 680, and 690 (in particular, wherein one or more coupling optical elements are reflection deflection optical elements). As illustrated, coupling optical elements 700, 710, and 720 may be disposed on the upper main surface of their respective waveguides 670, 680, and 690 (or on top of the next lower waveguide), particularly wherein those coupling optical elements are transmission deflection optical elements. In some embodiments, coupling optical elements 700, 710, and 720 may be disposed within the body of the respective waveguides 670, 680, and 690. In some embodiments, as discussed herein, coupling optical elements 700, 710, and 720 are wavelength selective, such that they selectively redirect one or more wavelengths of light while transmitting other wavelengths of light. Although illustrated on one side or corner of their respective waveguides 670, 680, and 690, it will be understood that in some embodiments, coupling optical elements 700, 710, and 720 may be disposed in other regions of their respective waveguides 670, 680, and 690.

[0172] As illustrated, the coupling optical elements 700, 710, and 720 can be laterally offset from each other, as seen in the top view shown in the direction of light propagation to these coupling optical elements. In some embodiments, each coupling optical element can be offset such that it receives light without the light passing through another coupling optical element. For example, each coupling optical element 700, 710, and 720 can be configured to receive light from, for example,... Figure 6 The different image injection devices 360, 370, 380, 390 and 400 shown receive light and can be separated from other coupled optical elements 700, 710, 720 (e.g., laterally spaced) so that they substantially do not receive light from other coupled optical elements among the coupled optical elements 700, 710, 720.

[0173] Each waveguide also includes associated light distribution elements, such as light distribution element 730 disposed on the main surface (e.g., top main surface) of waveguide 670, light distribution element 740 disposed on the main surface (e.g., top main surface) of waveguide 680, and light distribution element 750 disposed on the main surface (e.g., top main surface) of waveguide 690. In some other embodiments, light distribution elements 730, 740, and 750 may be disposed on the bottom main surface of associated waveguides 670, 680, and 690, respectively. In some other embodiments, light distribution elements 730, 740, and 750 may be disposed on the top and bottom main surfaces of associated waveguides 670, 680, and 690, respectively; or light distribution elements 730, 740, and 750 may be disposed on different main surfaces of the top and bottom main surfaces of different associated waveguides 670, 680, and 690.

[0174] Waveguides 670, 680, and 690 can be separated and isolated by layers of, for example, gaseous, liquid, and / or solid materials. For example, as illustrated, layer 760a can separate waveguides 670 and 680; and layer 760b can separate waveguides 680 and 690. In some embodiments, layers 760a and 760b are formed of a low-refractive-index material (i.e., a material having a lower refractive index than the material forming one of the directly adjacent waveguides of waveguides 670, 680, and 690). Preferably, the refractive index of the material forming layers 760a and 760b is 0.05 or more, or 0.10 or less, less than the refractive index of the material forming waveguides 670, 680, and 690. Advantageously, the lower-refractive-index layers 760a and 760b can be used as cladding layers that facilitate total internal reflection (TIR) ​​of light passing through waveguides 670, 680, and 690 (e.g., TIR between the top and bottom principal surfaces of each waveguide). In some embodiments, layers 760a and 760b are formed of air. Although not illustrated, it will be understood that the top and bottom of the illustrated waveguide assembly 660 may include directly adjacent cladding layers.

[0175] Preferably, for ease of manufacturing and other considerations, the materials forming waveguides 670, 680, and 690 are similar or identical, and the materials forming layers 760a and 760b are similar or identical. In some embodiments, the materials forming waveguides 670, 680, and 690 may differ between one or more waveguides, and / or the materials forming layers 760a and 760b may differ, while still maintaining the various refractive index relationships indicated above.

[0176] Continue to refer to Figure 9ALight rays 770, 780, and 790 are incident on waveguide assembly 660. It will be understood that light rays 770, 780, and 790 can be injected into waveguides 670, 680, and 690 via one or more image injection devices 360, 370, 380, 390, and 400. Figure 6 ).

[0177] In some embodiments, light rays 770, 780, and 790 have different properties, for example, corresponding to different wavelengths or different wavelength ranges for different colors. Coupled optical elements 700, 710, and 720 each deflect the incident light such that the light propagates through a TIR via a corresponding waveguide 670, 680, or 690. In some embodiments, coupled optical elements 700, 710, and 720 each selectively deflect one or more specific wavelengths of light while transmitting other wavelengths to the underlying waveguide and the associated coupled optical element.

[0178] For example, the coupling optical element 700 can be configured to deflect light 770 having a first wavelength or wavelength range while transmitting light 1242 and 1244 having different second and third wavelengths or wavelength ranges, respectively. Transmitted light 780 is incident on and deflected by the coupling optical element 710, which is configured to deflect light of the second wavelength or wavelength range. Light 790 is deflected by the coupling optical element 720, which is configured to selectively deflect light of a third wavelength or wavelength range.

[0179] Continue to refer to Figure 9A The deflected rays 770, 780, and 790 are deflected so that they propagate through their corresponding waveguides 670, 680, and 690; that is, the coupling optical elements 700, 710, and 720 of each waveguide deflect the light into its corresponding waveguide 670, 680, and 690 to couple the light into that waveguide. The rays 770, 780, and 790 are deflected at an angle so that the light propagates through the corresponding waveguides 670, 680, and 690 via TIR. The rays 770, 780, and 790 propagate through the corresponding waveguides 670, 680, and 690 via TIR until they are incident on the corresponding light distribution elements 730, 740, and 750 of the waveguides.

[0180] Now for reference Figure 9B , showed Figure 9AA perspective view of an example of multiple stacked waveguides. As described above, the coupled rays 770, 780, and 790 are deflected by coupled optical elements 700, 710, and 720, respectively, and then propagate within waveguides 670, 680, and 690 via TIR. Rays 770, 780, and 790 are then incident on light distribution elements 730, 740, and 750, respectively. Light distribution elements 730, 740, and 750 deflect rays 770, 780, and 790 so that they propagate toward coupled optical elements 800, 810, and 820, respectively.

[0181] In some embodiments, light distribution elements 730, 740, and 750 are orthogonal pupil expanders (OPEs). In some embodiments, the OPE deflects or distributes light to output optics 800, 810, and 820, and in some embodiments, it can also increase the beam size or spot size as the light propagates to the output optics. In some embodiments, light distribution elements 730, 740, and 750 may be omitted, and input optics 700, 710, and 720 may be configured to directly deflect light to output optics 800, 810, and 820. For example, refer to... Figure 9A The light distribution elements 730, 740, and 750 can be replaced by coupling optical elements 800, 810, and 820, respectively. In some embodiments, the coupling optical elements 800, 810, and 820 are exit pupils (EP) or exit pupil expanders (EPE) that guide light into the observer's eye 210. Figure 7 It will be understood that an OPE can be configured to increase the size of an eyebox on at least one axis, and an EPE can increase an eyebox on an axis spanning (e.g., orthogonal to) the OPE. For example, each OPE can be configured to redirect a portion of the light incident on the OPE to an EPE with the same waveguide, while allowing the remaining portion of the light to continue propagating down the waveguide. Upon re-incident on the OPE, another portion of the remaining light is redirected to the EPE, and that remaining portion continues to propagate further down the waveguide, and so on. Similarly, upon incident on an EPE, a portion of the incident light is directed toward the user out of the waveguide, and the remaining portion of that light continues to propagate through the waveguide until it is re-incident on the EP, at which point another portion of the incident light is directed out of the waveguide, and so on. Thus, a single beam of coupled light can be “replicated” each time a portion of that light is redirected by an OPE or EPE, thereby forming a field of cloned beams, such as Figure 6 As shown in the figure. In some embodiments, OPE and / or EPE can be configured to modify the size of the beam.

[0182] Therefore, refer to Figure 9A and 9BIn some embodiments, waveguide set 660 includes waveguides 670, 680, 690 for each component color; coupling optics 700, 710, 720; light distribution elements (e.g., OPE) 730, 740, 750; and coupling out optics (e.g., EPE) 800, 810, 820. Waveguides 670, 680, 690 may be stacked with a gap / cladding between each. The coupling optics 700, 710, 720 redirect or deflect incident light (where different coupling optics receive light of different wavelengths) into their respective waveguides. The light then propagates at an angle that will result in a TIR within the respective waveguide 670, 680, 690. In the example shown, ray 770 (e.g., blue light) is deflected by the first coupled-in optics 700 in the manner previously described, and then continues to bounce down along the waveguide, interacting with the light distribution element (e.g., OPE) 730 and then the coupled-out optics (e.g., EP) 800. Rays 780 and 790 (e.g., green and red light, respectively) will pass through waveguide 670, where ray 780 is incident on and deflected by coupled-in optics 710. Ray 780 then bounces down along waveguide 680 via TIR, continuing to its light distribution element (e.g., OPE) 740 and then the coupled-out optics (e.g., EP) 810. Finally, ray 790 (e.g., red light) passes through waveguide 690 to be incident in the light coupled-in optics 720 of waveguide 690. The light-coupled optical element 720 deflects the light ray 790, causing the light to propagate via TIR to the light distribution element (e.g., OPE) 750, and then via TIR to the output optical element (e.g., EP) 820. The output optical element 820 then finally couples the light ray 790 out to an observer, who also receives the coupled light from other waveguides 670, 680.

[0183] Figure 9C It shows Figure 9A and 9BA top plan view of an example of multiple stacked waveguides. It will be understood that this top view can also be referred to as a front view, as seen in the direction of light propagation toward the coupled optics 800, 810, 820; that is, the top view is a view of the waveguides with image light incident perpendicular to the page. As illustrated, waveguides 670, 680, 690, together with their associated light distribution elements 730, 740, 750 and associated coupled optics 800, 810, 820, can be vertically aligned. However, as discussed herein, the coupled optics 700, 710, 720 are not vertically aligned; instead, the coupled optics are preferably non-overlapping (e.g., laterally spaced, as seen in the top-down view). As further discussed herein, this non-overlapping spatial arrangement facilitates the injection of light from different sources into different waveguides on a one-to-one basis, thereby allowing a specific light source to be uniquely coupled to a specific waveguide. In some embodiments, an arrangement including non-overlapping, spatially separated coupled optical elements may be referred to as an offset pupil system, and the coupled optical elements within such arrangements may correspond to sub-pupils.

[0184] It will be understood that, as seen in the top view, spatially overlapping areas may have 70% or more, 80% or more, or 90% or more lateral overlap of their respective areas. On the other hand, as seen in the top view, laterally shifted areas may have less than 30%, less than 20%, or less than 10% overlap of their respective areas. In some embodiments, the laterally shifted areas have no overlap.

[0185] Figure 9D A top plan view of another example of multiple stacked waveguides is shown. As shown, waveguides 670, 680, and 690 can be vertically aligned. However, with Figure 9CCompared to the previous configuration, the individual light distribution elements 730, 740, 750 and the associated coupling optical elements 800, 810, 820 are omitted. Instead, as seen in the top view, the light distribution elements and coupling optical elements are effectively superimposed and occupy the same area. In some embodiments, the light distribution elements (e.g., OPE) may be disposed on one main surface of waveguides 670, 680, 690, while the coupling optical elements (e.g., EPE) may be disposed on another main surface of those waveguides. Thus, each waveguide 670, 680, 690 may have superimposed light distribution and coupling optical elements, collectively referred to as combined OPE / EPE 1281, 1282, 1283, respectively. Further details regarding such combined OPE / EPE can be found in U.S. Application No. 16 / 221,359, filed December 14, 2018, the entire disclosure of which is incorporated herein by reference. Coupled optical elements 700, 710, and 720 couple light into and guide it to the combined OPE / EPE 1281, 1282, and 1283, respectively. In some embodiments, as shown, the coupled optical elements 700, 710, and 720 may be laterally shifted (e.g., they are laterally spaced, as seen in the top view shown) and have a shifted pupil spatial arrangement. Figure 9C Similar to the configuration, this laterally shifted spatial arrangement is advantageous for injecting light of different wavelengths (e.g., from different light sources) into different waveguides on a one-to-one basis.

[0186] Figure 9E A top plan view shows another example of the configuration for the coupling optics 700, 710, 720. As shown, the coupling optics 700, 710, 720 can be shifted such that they are spaced apart in a triangular pattern when viewed from the top view. It will be understood that in this configuration, the spatial arrangement of the coupling optics 700, 710, 720 can match the spatial arrangement of one or more nanowire LED arrays 1030a, 1030b, 1030c. In some embodiments, these nanowire LED arrays 1030a, 1030b, 1030c can be formed on a common substrate or backplane 1093. In some embodiments, each of the nanowire LED arrays 1030a, 1030b, 1030c can be configured to emit light with different component colors (e.g., red, green, and blue).

[0187] Figure 9F Examples of wearable display systems 60 to which the various waveguides and related systems disclosed herein can be integrated are shown. In some embodiments, display system 60 is Figure 6 The system 250, of which, Figure 6 Some parts of the system 60 are illustrated in more detail. For example, Figure 6The waveguide component 260 may be part of the display 70.

[0188] Continue to refer to Figure 9F The display system 60 includes a display 70 and various mechanical and electronic modules and systems supporting the functionality of the display 70. The display 70 may be coupled to a frame 80, which may be worn by a user or observer 90 of the display system and configured to position the display 70 in front of the user 90's eyes. In some embodiments, the display 70 may be considered as eyeglasses. In some embodiments, a speaker 100 is coupled to the frame 80 and configured to be located near the user 90's ear canal (in some embodiments, another speaker, not shown, may alternatively be located near the user's other ear canal to provide stereo / shape-shifting sound control). The display system 60 may also include one or more microphones 110 or other devices for sound detection. In some embodiments, the microphone is configured to allow the user to provide input or commands to system 60 (e.g., voice menu commands, natural language questions, etc.) and / or to allow audio communication with other people (e.g., with other users of similar display systems). The microphone may also be configured as a peripheral sensor to collect audio data (e.g., sounds from the user and / or environment). In some embodiments, display system 60 may also include one or more outward-oriented environmental sensors 112 configured to detect objects, stimuli, people, animals, locations, or other aspects of the world around the user. For example, environmental sensor 112 may include one or more cameras that may be, for example, outward-oriented to capture images similar to at least a portion of the user 90's normal field of view. In some embodiments, display system may also include peripheral sensors 120a that may be detached from frame 80 and attached to the user 90's body (e.g., on the user 90's head, torso, limbs, etc.). In some embodiments, peripheral sensor 120a may be configured to acquire data characterizing the user 90's physiological state. For example, sensor 120a may be an electrode.

[0189] Continue to refer to Figure 9FThe display 70 is operatively coupled to the local data processing module 140 via a communication link 130 (e.g., via a wired lead or wireless connection). The local data processing module 140 can be mounted in various configurations, such as being fixedly attached to the frame 80, fixedly attached to a helmet or hat worn by the user, embedded in headphones, or detachably attached to the user 90 (e.g., in a backpack configuration or a strap-coupled configuration). Similarly, the sensor 120a can be operatively coupled to the local processor and data module 140 via a communication link 120b (e.g., via a wired lead or wireless connection). The local processing and data module 140 may include a hardware processor and digital memory such as non-volatile memory (e.g., flash memory or hard disk drive), both of which can be used for auxiliary processing, caching, and storing data. Alternatively, the local processor and data module 140 may include one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. Data may include: a) data captured from sensors (e.g., sensors that may be operatively coupled to frame 80 or otherwise attached to user 90), such as image capture devices (e.g., cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, radio devices, gyroscopes, and / or other sensors disclosed herein; and / or b) data acquired and / or processed using remote processing module 150 and / or remote data storage 160 (including data related to virtual content), which may be transmitted to display 70 after such processing or retrieval. Local processing and data module 140 may be operatively coupled to remote processing module 150 and remote data storage 160 via communication links 170, 180 (e.g., via wired or wireless communication links), such that these remote modules 150, 160 are operatively coupled to each other and can be used as resources of local processing and data module 140. In some embodiments, the local processing and data module 140 may include one or more of an image capture device, a microphone, an inertial measurement unit, an accelerometer, a compass, a GPS unit, a radio device, and / or a gyroscope. In some other embodiments, one or more of these sensors may be attached to the frame 80, or may be a separate structure that communicates with the local processing and data module 140 via a wired or wireless communication path.

[0190] Continue to refer to Figure 9FIn some embodiments, the remote processing module 150 may include one or more processors configured to analyze and process data and / or image information, such as one or more central processing units (CPUs), graphics processing units (GPUs), dedicated processing hardware, etc. In some embodiments, the remote data repository 160 may include a digital data storage facility that may be available via the Internet or other network configurations in a "cloud" resource configuration. In some embodiments, the remote data repository 160 may include one or more remote servers that provide information, such as information for generating virtual content, to the local processing and data module 140 and / or the remote processing module 150. In some embodiments, all data is stored and all computations are performed in the local processing and data module, thereby allowing fully autonomous use from the remote module. Alternatively, an external system including a CPU, GPU, etc. (e.g., a system with one or more processors, one or more computers) may perform at least a portion of the processing (e.g., generating image information, processing data) and provide and receive information to and from modules 140, 150, 160, for example, via wireless or wired connections.

[0191] Figure 10 An example of a wearable display system with a light projection system 910 is shown, which includes a spatial light modulator 930 and a separate light source 940. The light source 940 may include one or more light emitters and illuminate the spatial light modulator (SLM) 930. A lens structure 960 is used to focus the light from the light source 940 onto the SLM 930. A beamsplitter (e.g., a polarization beamsplitter (PBS)) 950 reflects the light from the light source 940 to the spatial light modulator 930, which reflects and modulates the light. The reflected modulated light (also referred to as image light) is then propagated through the beamsplitter 950 to an eyepiece 920. Another lens structure, projection optics 970, is used to converge or focus the image light onto the eyepiece 920. The eyepiece 920 may include one or more waveguides or waveguides that relay the modulation to an eye 210.

[0192] As described herein, the individual light source 940 and associated lens structure 960 may undesirably add weight and size to the wearable display system. This could reduce the comfort of the display system, especially for users who wear it for extended periods.

[0193] Furthermore, the combination of light source 940 and SLM 930 may inefficiently consume energy. For example, light source 940 may illuminate the entire SLM 930. SLM 930 then selectively reflects light towards eyepiece 920. Therefore, not all the light generated by light source 940 is available for image formation; some of this light, for example, light corresponding to dark areas of the image, is not reflected to eyepiece 920. Thus, light source 940 uses energy to generate light to illuminate the entire SLM 930, but may only require a portion of that light to form some of the image.

[0194] Moreover, as described herein, in some cases, the SLM 930 can modulate light by selectively reflecting incident light using micromirrors, or by using liquid crystal molecules to modify the amount of light reflected from a mirror below. Therefore, such a device requires physical movement of optical elements (e.g., micromirrors or liquid crystal molecules) to modulate light from the light source 940. For example, compared to the ability to “turn on” or “turn off” an LED or OLED, the physical movement required to modulate light to encode it with image information (e.g., corresponding to pixels) may occur at a relatively slow rate. This relatively slow movement may limit the frame rate of the display system and can be considered, for example, motion blur, color degradation, and / or a presented image that does not match the user’s head posture or changes in said posture.

[0195] Advantageously, as disclosed herein, wearable displays utilizing nanowire LED microdisplays can benefit from wearable display systems with relatively low weight and volume, high energy efficiency and high frame rate, and low motion blur and low motion-to-photon delay. Low blur and low motion-to-photon delay are further discussed in U.S. Provisional Application No. 62 / 786199, filed December 28, 2018, the entire disclosure of which is incorporated herein by reference. Furthermore, compared to scanning fiber optic displays, nanowire LED microdisplays can avoid artifacts caused by the use of coherent light sources.

[0196] Now for reference Figure 11A An example of a wearable display system with a light projection system 1010 is shown, the light projection system 1010 having multiple nanowire LED microdisplays 1030a, 1030b, 1030c. Light from the microdisplays 1030a, 1030b, 1030c is combined by an optical combiner 1050 and directed to an eyepiece 1020, which relays the light to the user's eye 210. A projection optics 1070 may be provided between the optical combiner 1050 and the eyepiece 1020. In some embodiments, the eyepiece 1020 may be a waveguide assembly including one or more waveguides. In some embodiments, the light projection system 1010 and the eyepiece 1020 may be formed by a frame 80 (…). Figure 9FSupport (e.g., attached to a frame).

[0197] In some embodiments, the microdisplays 1030a, 1030b, and 1030c may be monochrome microdisplays, wherein each monochrome microdisplay outputs light of a different component color to provide a monochrome image. As discussed herein, monochrome images are combined to form a panchromatic image.

[0198] In some other embodiments, each of the microdisplays 1030a, 1030b, and 1030c may be a full-color display configured to output light of all component colors. For example, each of the microdisplays 1030a, 1030b, and 1030c includes red, green, and blue light emitters. The microdisplays 1030a, 1030b, and 1030c may be identical and may display the same image. However, by combining light from multiple microdisplays to form a single image, utilizing multiple microdisplays can provide the advantage of a luminance dynamic range for increasing brightness and image brightness. In some embodiments, two or more (e.g., three) microdisplays may be utilized, wherein the optical combiner 1050 is configured to combine light from all of these microdisplays.

[0199] Continue to refer to Figure 11A Each of the microdisplays 1030a, 1030b, and 1030c can be configured to emit image light 1032a, 1032b, and 1032c. In the case that the microdisplay is a monochrome microdisplay, each of the image light 1032a, 1032b, and 1032c can have different component colors. An optical combiner 1050 receives the image light 1032a, 1032b, and 1032c and effectively combines the light such that the light propagates substantially in the same direction, for example, toward the projection optics 1070. In some embodiments, the optical combiner 1050 can be a dichroic X-cube prism having a reflective inner surface that redirects the image light 1032a, 1032b, and 1032c to the projection optics 1070. It will be understood that the projection optics 1070 can be a lens structure including one or more lenses that converge or focus the image light onto the eyepiece 1020. The eyepiece 1020 then relays the image light 1032a, 1032b, 1032c to the eye 210.

[0200] In some embodiments, eyepiece 1020 may include a plurality of stacked waveguides 1020a, 1020b, 1020c, each having a corresponding coupling optics 1022a, 1022b, 1022c. In some embodiments, the number of waveguides is proportional to the number of component colors provided by microdisplays 1030a, 1030b, 1030c. For example, in the presence of three component colors, the number of waveguides in eyepiece 1020 may include a set of three waveguides or multiple sets of waveguides, each set containing three waveguides. In some embodiments, each set may output light having a wavefront divergence corresponding to a specific depth plane, as discussed herein. It will be understood that waveguides 1020a, 1020b, 1020c and coupling optics 1022a, 1022b, 1022c may respectively correspond to Figures 9A-9C Waveguides 670, 680, 690 and coupling optical elements 700, 710, 720. As can be observed from the projection optics 1070, coupling optical elements 1022a, 1022b, 1022c can be laterally shifted so that they do not overlap at least partially, as seen in such a view.

[0201] As shown in the figures, the various coupling optical elements disclosed herein (e.g., coupling optical elements 1022a, 1022b, 1022c) can be disposed on the main surface of an associated waveguide (e.g., waveguides 1020a, 1020b, 1020c, respectively). Additionally, as also shown, the main surface on which a given coupling optical element is disposed can be the rear surface of the waveguide. In such a configuration, the coupling optical element can be a reflected light redirection element that couples light by reflecting light at an angle supporting the TIR of the associated waveguide. In some other configurations, the coupling optical element can be disposed on the front surface of the waveguide (closer to the projection optics 1070 than the rear surface). In such a configuration, the coupling optical element can be a transmitted light redirection element that couples light by changing the direction of light propagation as light is transmitted through the coupling optical element. It will be understood that any coupling optical element disclosed herein can be a reflective or transmissive coupling optical element.

[0202] Continue to refer to Figure 11AImage lights 1032a, 1032b, and 1032c from different microdisplays in microdisplays 1030a, 1030b, and 1030c can take different paths to the eyepiece 1020, so that they are incident on different coupling optical elements 1022a, 1022b, and 1022c. When the image lights 1032a, 1032b, and 1032c include light with different component colors, the associated coupling optical elements 1022a, 1022b, and 1022c can be configured to selectively couple light of different wavelengths, as described above. Figures 9A-9C The coupling optical elements 700, 710, and 720 are discussed.

[0203] Continue to refer to Figure 11AThe optical combiner 1050 can be configured to redirect image light 1032a, 1032b, 1032c emitted by microdisplays 1030a, 1030b, 1030c along different optical paths to incident on a suitable associated coupling optics among coupling optics 1022a, 1022b, 1022c. Thus, the optical combiner 1050 combines image light 1032a, 1032b, 1032c in the sense that the image light exits from the common surface of the optical combiner 1050, even though the light may exit the optical combiner in slightly different directions. For example, the reflective inner surfaces 1052, 1054 of the X-cube prism can each be angled to guide image light 1032a, 1032b, 1032c along different paths to the eyepiece 1020. Therefore, image light 1032a, 1032b, 1032c can be incident on different associated coupling optical elements among the coupling optical elements 1022a, 1022b, 1022c. In some embodiments, microdisplays 1030a, 1030b, 1030c can be appropriately angled relative to the reflective inner surfaces 1052, 1054 of the X-cube prism to provide a desired optical path to the coupling optical elements 1022a, 1022b, 1022c. For example, the faces of one or more microdisplays 1030a, 1030b, 1030c can be angled to match the faces of the optical combiner 1050, such that image light emitted by the microdisplay is incident at an appropriate angle on the reflective inner surfaces 1052, 1054 to propagate toward the associated coupling optical element 1022a, 1022b, or 1022c. In some embodiments, as discussed herein, microline LEDs can be advantageously designed to provide directional light output. The dominant direction of light output can be selected for each of the microdisplays 1030a, 1030b, and 1030c, such that light propagates along an appropriate optical path from each of these microdisplays to a corresponding coupling optical element in coupling optical elements 1022a, 1022b, and 1022c. It will be understood that, in addition to a cube, the optical combiner 1050 can take the form of various other polyhedra. For example, the optical combiner 1050 can be in the shape of a rectangular prism having at least two non-square faces.

[0204] Continue to refer to Figure 11AIn some embodiments, the monochrome microdisplay 1030b, directly opposite the output surface 1051, can advantageously output green light. It will be understood that reflective surfaces 1052 and 1054 may have optical losses when reflecting light from the microdisplay. Furthermore, the human eye is most sensitive to green. Therefore, the monochrome microdisplay 1030b, opposite the output surface 1051, preferably outputs green light so that the green light can proceed directly through the optical combiner 1050 without being reflected before being output from the optical combiner 105. However, it will be understood that in some other embodiments, the green monochrome microdisplay may face other surfaces of the optical combiner 1050.

[0205] As discussed herein, in some embodiments, the user's perception of a panchromatic image can be achieved through time-division multiplexing. For example, different nanowire LED microdisplays in nanowire LED microdisplays 1030a, 1030b, and 1030c can be activated at different times to generate different component color images. In such embodiments, the different component color images forming a single panchromatic image can be displayed sequentially fast enough that the human visual system does not perceive the component color images as being displayed at different times; that is, the different component color images forming a single panchromatic image can all be displayed within a sufficiently short duration so that the user perceives the component color images as being presented simultaneously, rather than being temporally separated. For example, it will be understood that the human visual system can have a flicker fusion threshold. A flicker fusion threshold can be understood as the duration at which the human visual system cannot distinguish an image as being presented at different times. Images presented within this duration are fused or combined, and therefore, can be perceived by the user as being presented simultaneously. Flickering images with time gaps between images outside this duration are not combined, and the flickering of the image is perceptible. In some embodiments, the duration is 1 / 60 of a second or less, which corresponds to a frame rate of 60 Hz or more. Preferably, image frames for any individual eye are provided to the user at a frame rate equal to or higher than the user's flicker fusion threshold for a duration. For example, the frame rate for each of the left or right eyepieces may be 60 Hz or more, or 120 Hz or more; and therefore, in some embodiments, the frame rate provided by the light projection system 1010 may be 120 Hz or more, or 240 Hz or more. It will be understood that time-division multiplexing can advantageously reduce the computational load on the processor (e.g., graphics processor) used to form the displayed image. In some other embodiments, such as when sufficient computational resources are available, all component color images forming a panchromatic image may be simultaneously displayed by the microdisplays 1030a, 1030b, 1030c.

[0206] As discussed herein, the microdisplays 1030a, 1030b, and 1030c may each include an array of nanowire LED light emitters for forming an image. Figure 11B An example of an array 1042 of light emitters 1044 is shown. In the case that the associated microdisplay is a monochrome microdisplay, all of the light emitters 1044 can be configured to emit light of the same color.

[0207] When the associated microdisplay is a full-color microdisplay, the different light emitters in the light emitter 1044 can be configured to emit light of different colors. In such an embodiment, the light emitter 1044 can be considered as sub-pixels and can be arranged in groups, with each group having at least one light emitter configured to emit light of each component color. For example, when the component colors are red, green, and blue, each group can have at least one red sub-pixel, at least one green sub-pixel, and at least one blue sub-pixel.

[0208] It will be understood that although the light emitter 1044 is shown as arranged in a grid pattern for ease of illustration, the light emitter 1042 may have other regularly repeating spatial arrangements. For example, the number of light emitters of different component colors may vary, the size of the light emitters may vary, the shape of the light emitters and / or the shape formed by the groups of light emitters may vary, and so on.

[0209] Figure 11C It shows Figure 11B A cross-sectional side view of a nanowire LED array 1042. In some embodiments, the nanowire LED array 1042 may include one or more nanowires 1094, which may be light-emitting diode elements. In some embodiments, the nanowire array may be a uniform array of nanowires 1094. As an example, the nanowires 1094 may have a height of 10-10000 nm, 100-1000 nm, 500-1000 nm, or 700-1000 nm, and a width of, for example, 10-1000 nm, including 200 nm or less, or 100 nm or less and greater than 10 nm. In some embodiments, the nanowires 1094 may be cylindrical, and the width may correspond to the diameter of the nanowire. The nanowires 1094 may be grouped into pixels defined by electrical contacts 1095, which are shared by each group of nanowires 1095. It will be understood that each group of nanowires 1094 forming a pixel may share a second electrical contact (not shown). Each pixel that may include a group of nanowires may be a separate light emitter 1044.

[0210] Continue to refer to Figure 11CNanowire LEDs can utilize inorganic materials, such as group III-V materials like GaAs, GaN, and / or GaIn, and can be grown on a substrate 1093, which can be a backplane containing various electronic devices, such as CMOS devices for controlling the operation of the nanowire LEDs. Examples of GaN materials include InGaN, which in some embodiments can be used to form blue or green light emitters. Although other materials can be utilized in various embodiments, GaN can be advantageously used to generate the entire visible spectrum simply by controlling the In doping concentration to achieve desired electronic bandgap tuning, resulting in the emission of light at the desired wavelength. Thus, the nanowires can be monochromatic, and each group can emit the same color, or different pixels can emit different colors of light by using different doping levels for different pixels. Thus, blue, green, and red emitters can all be formed on a single GaN semiconductor, simplifying fabrication and increasing manufacturing throughput. Furthermore, GaN and InGaN can be grown on standard semiconductor materials such as silicon, which allows for integration with associated microelectronic circuitry (CMOS Si backplane) for driving nanowire LED pixels.

[0211] Examples of GaIn materials include AlGaInP, which in some embodiments can be used to form red light emitters.

[0212] Now for reference Figure 12 Another example of a wearable display system with a light projection system is shown, which has multiple nanowire LED microdisplays 1030a, 1030b, and 1030c. The display system shown is similar to... Figure 11A The display system, in addition to having a standard X-cube prism configuration in the optical combiner 1050 and including light redirecting structures 1080a and 1080c, is used to modify the incident angle of light on the reflecting surfaces 1052 and 1054 of the X-cube prism. It will be understood that the standard X-cube prism configuration receives light perpendicular to the face of the X-cube and redirects that light by 45°, so that it exits at a vertical angle from the transverse surface of the X-cube. However, this results in image lights 1032a, 1032b, and 1032c being incident on the same coupling optics of the eyepiece 1020. To provide different paths for the image lights 1032a, 1032b, and 1032c, such that the image light is incident on the associated coupling optics of the waveguide assembly's coupling optics 1022a, 1022b, and 1022c, the light redirecting structures 1080a and 1080c can be utilized.

[0213] In some embodiments, the light redirection structures 1080a and 1080c may be lens structures. It will be understood that the lens structure can be configured to receive incident light and redirect it at an angle, such that the light is reflected from a corresponding reflective surface of the reflective surfaces 1052 and 1054 and propagates along the optical path toward a corresponding coupled optical element of the coupled optical elements 1022a and 1022c. As an example, the light redirection structures 1080a and 1080c may include microlenses, nanolenses, reflective traps, metasurfaces, and liquid crystal gratings. In some embodiments, the microlenses, nanolenses, reflective traps, metasurfaces, and liquid crystal gratings may be organized in an array. For example, each light emitter of the microdisplays 1030a and 1030c may be matched with a microlens. In some embodiments, to redirect light in a particular direction, the microlens or reflective trap may be asymmetrical and / or the light emitter may be positioned off-center relative to the microlens. Additionally, in some embodiments, the light reguiding structures 1080a and 1080c can be collimators that narrow the angular emission profile of the associated light emitter to increase the amount of light ultimately coupled into the eyepiece 1020. The following is about... Figures 24A to 27 C discusses further details regarding such optically guided structures 1080a and 1080c.

[0214] Continue to refer to Figure 12 In some embodiments, one or both of the light reguiding structures 1080a, 1080c may be omitted, and the nanowire LEDs of the nanowire LED microdisplays 1030a, 1030b, 1030c may be configured to emit light with a desired directional orientation to propagate along the optical path to the associated coupling optical elements 1022a, 1022b, 1022c. As discussed herein, the nanowire LEDs may be designed with a selective directional orientation that may not be perpendicular to the light output surface of the associated microdisplay. Therefore, in some embodiments, the physical design and composition of the nanowire LEDs of each of the nanowire LED microdisplays 1030a, 1030b, 1030c may be selected to provide light output in different directions as shown in the figure.

[0215] Now for reference Figure 13A In some embodiments, two or more of the coupled optical elements 1022a, 1022b, 1022c may overlap (e.g., as seen in a front view in the direction of light propagation to coupled optical elements 1022a, 1022b, 1022c). Figure 13AAn example side view of a wearable display system with a light projection system 1010 is shown, which has multiple nanowire LED microdisplays 1032a, 1032b, 1032c and an eyepiece 1020 with overlapping light-coupled optics 1022a, 1022c and a non-overlapping light-coupled optics 1022b. As shown, the coupling optics 1022a and 1022c overlap, while the coupling optics 1022b are laterally shifted. In other words, the coupling optics 1022a and 1022c are directly aligned in the path of the image light 1032a and 1032c, while the image light 1032b follows a different path to the eyepiece 1020, such that it is incident on a region of the eyepiece 1020 that is laterally shifted relative to the region where the image light 1032a and 1032c are incident.

[0216] As shown, optical reguiding structures 1080a and 1080c can be used to establish a difference between the paths for image light 1032b and image lights 1031a and 1032c. In some embodiments, image light 1032b from the nanowire LED microdisplay 1030b travels directly through the optical combiner 1052. Image light 1032a from the nanowire LED microdisplay 1032a is reguided by optical reguiding structure 1080a, causing it to reflect off the reflective surface 1054 and propagate outside the optical combiner 1050 in the same direction as image light 1032c. It will be understood that image light 1032c from the nanowire LED microdisplay 1032c is reguided by optical reguiding structure 1080c, causing it to reflect off the reflective surface 1052 at an angle, so that image light 1032c propagates outside the optical combiner 1050 in the same direction as image light 1032b. Therefore, the angles of the light reguiding structures 1080a and 1080c and the reflective surfaces 1052 and 1054 are configured to provide a common path for the image lights 1032a and 1032c to reach the optical combiner 1050, where this common path differs from the path of the image light 1032b. In some other embodiments, one or both of the light reguiding structures 1080a and 1080c may be omitted, and the reflective surfaces 1052 and 1054 in the optical combiner 1050 may be configured to reflect the image lights 1032a and 1032c in appropriate corresponding directions, such that they exit the optical combiner 1050 and propagate in the same direction as the image light 1032b, different from the direction of the image light 1032b. Thus, after propagation through the projection optics 1070, the image lights 1032a and 1032c exit from one exit pupil, while the image light 1032b exits from the other exit pupil. In this configuration, the light projection system 1010 can be referred to as a dual-pupil projection system.

[0217] In some embodiments, the light projection system 1010 may have a single output pupil and may be referred to as a single-pupil projection system. In such embodiments, the light projection system 1010 may be configured to direct image light 1032a, 1032b, 1032c onto a single common area of ​​the eyepiece 1020. Figure 13B This configuration is shown. Figure 13B A wearable display system with a light projection system 1010 is illustrated, which has multiple nanowire LED microdisplays 1030a, 1030b, 1030c configured to guide light to a single light-coupled region of an eyepiece 1020. In some embodiments, as further discussed herein, the eyepiece 1020 may include a stack of waveguides with overlapping light-coupled optics. In some other embodiments, a single light-coupled optic may be configured to couple light of all component colors into a single waveguide. In some embodiments, the single waveguide may be formed of a high-refractive-index material, such as silicon carbide (SiC).

[0218] Figure 13B The display system is similar to Figure 13A The display system, except that the light redirection structures 1080a and 1080c are omitted, uses a coupling optical element 1122a and an associated waveguide 1020a. As shown, the coupling optical element 1122a couples each of the image lights 1032a, 1032b, and 1032c into the waveguide 1020a, which then relays the image light to the eye 210. In some embodiments, the coupling optical element 1122a may include a diffraction grating. In some embodiments, the coupling optical element 1122a is a metasurface and / or a liquid crystal grating.

[0219] In some other embodiments, waveguide 1020a may include two or more spaced-apart coupling optical elements, and each of the two or more spaced-apart coupling optical elements may be configured to couple light of different wavelength ranges (e.g., different colors). It will be understood that the spaced-apart coupling optical elements may be spatially separated, as seen in a top plan view (e.g., viewed from the front in the direction of light incident on waveguide 1020a). For example, waveguide 1020a may include coupling optical elements 1022a, 1022b, 1022c on this single waveguide (e.g., as shown in the image). Figure 11A (in the side view) or Figure 9COr as shown in 9D (in top view), although spatially separated on the same waveguide 1020b, the coupling optics are spatially separated such that different colors of image light from the light projection system 1010 are uniquely incident on one of the associated coupling optics 1022a, 1022b, 1022c. In some embodiments, two spatially separated coupling optics may be used, wherein at least one of the coupling optics is configured to couple multiple different colors of light. For example, in such an arrangement, the coupling optics can be coupled with... Figure 13A The coupling elements 1022a and 1022b (in the side view) are arranged in a similar manner, although they are spatially separated on the same waveguide 1020a.

[0220] As discussed herein, in some embodiments, nanowire LED microdisplays 1030a, 1030b, and 1030c may be monochromatic microdisplays configured to emit light of different colors. In some embodiments, one or more of nanowire LED microdisplays 1030a, 1030b, and 1030c may have light emitter groups configured to emit two or more, but not all, component colors of light. For example, a single nanowire LED microdisplay may have multiple light emitter groups—where at least one light emitter in each group is configured to emit blue light and at least one light emitter in each group is configured to emit green light—and individual nanowire LED microdisplays on different faces of the X-cube 1050 may have light emitters configured to emit red light. In some other embodiments, nanowire LED microdisplays 1030a, 1030b, and 1030c may each be a full-color display, each full-color display having light emitters for all component colors. As described herein, utilizing multiple similar microdisplays can provide advantages for dynamic range and increased display brightness.

[0221] In some embodiments, a single full-color nanowire LED microdisplay can be used. Figure 14 An example of a wearable display system with a single nanowire LED microdisplay 1030b is shown. Figure 14 Wearable display systems are similar to Figure 13A and 13B The wearable display system, in addition to a single nanowire LED microdisplay 1030b, is a full-color microdisplay configured to emit light of all component colors. As shown, the microdisplay 1030b emits image light 1032a, 1032b, and 1032c for each component color. In such an embodiment, the optical combiner 1050 can be omitted. Figure 13B This can advantageously reduce the weight and size of wearable display systems compared to systems with optical combiners.

[0222] As discussed above, the coupling optics of eyepiece 1020 can be configured in various ways. The following section discusses... Figure 15-23C Some examples of configurations used for eyepiece 1020 are discussed.

[0223] Figure 15 A side view is shown of an example of an eyepiece 1020 having a stack of waveguides 1020a, 1020b, 1020c with overlapping coupled optical elements 1022a, 1022b, 1022c, respectively. It will be understood that the waveguide stack shown can be used instead... Figure 13B and 14 A single waveguide 1020a is shown. As discussed herein, each of the coupling optics 1022a, 1022b, 1022c is configured to couple light of a specific color (e.g., light of a specific wavelength or wavelength range). In the illustrated orientation of the eyepiece 1020, where the image light propagates vertically downwards along the page toward the eyepiece 1020, the coupling optics 1022a, 1022b, 1022c are perpendicularly aligned with each other (e.g., along an axis parallel to the propagation direction of the image light 1032a, 1032b, 1032c) such that they spatially overlap each other as seen in the top view (a front view in the direction in which the image light 1032a, 1032b, 1032c propagates to the coupling optics).

[0224] Continue to refer to Figure 15 As discussed herein, the projection system 1010 (Figures 13, 14) is configured to output a first monochrome image, a second monochrome image, and a third monochrome image (e.g., red, green, and blue images) through a single pupil of the projection system, the monochrome images being formed by image lights 1032a, 1032b, and 1032c, respectively. Coupled optical element 1022c is configured to couple image light 1032c for a first color image into waveguide 1020c such that it propagates through waveguide 1020c via multiple total internal reflections at the upper and lower main surfaces of waveguide 1020c; coupled optical element 1022b is configured to couple image light 1032b for a second color image into waveguide 1020b such that it propagates through waveguide 1020b via multiple total internal reflections at the upper and lower main surfaces of waveguide 1020b; and coupled optical element 1022a is configured to couple image light 1032a for a third color image into waveguide 1020a such that it propagates through waveguide 1020a via multiple total internal reflections at the upper and lower main surfaces of waveguide 1020a.

[0225] As discussed herein, the coupling optical element 1022c is preferably configured to couple substantially all of the incident light 1032c corresponding to the first color image into the associated waveguide 1020c, while allowing substantially all of the incident light 1032b, 1032a corresponding to the second and third color images, respectively, to be transmitted without coupling. Similarly, the coupling optical element 1022b is preferably configured to couple substantially all of the incident image light 1032b corresponding to the second color image into the associated waveguide 1020b, while allowing substantially all of the incident light corresponding to the third color image to be transmitted without coupling.

[0226] It will be understood that, in practice, the various coupling optical elements may not have perfect selectivity. For example, some of the image light 1032b and 1032a may undesirably be coupled into waveguide 1020c via coupling optical element 1022c; and some of the incident image light 1032a may undesirably be coupled into waveguide 1020b via coupling optical element 1022b. Furthermore, some of the image light 1032c may be transmitted through coupling optical element 1022c and coupled into waveguide 1020b and / or 1020a via coupling optical elements 1020b and / or 1020a, respectively. Similarly, some of the image light 1032b may be transmitted through coupling optical element 1022b and coupled into waveguide 1020a via coupling optical element 1022a.

[0227] Coupled image light for a color image into an unintended waveguide may cause undesirable optical effects, such as crosstalk and / or ghosting. For example, coupling image light 1032c for a first color image into unintended waveguides 1020b and / or 1020a may cause undesirable crosstalk between the first, second, and / or third color images; and / or may cause undesirable ghosting. As another example, coupling image light 1032b, 1032a for a second or third color image into unintended waveguide 1020c may cause undesirable crosstalk between the first, second, and / or third color images; and / or may cause undesirable ghosting. In some embodiments, these undesirable optical effects can be mitigated by providing a color filter (e.g., an absorptive color filter) that reduces the amount of incident light coupled into the unintended waveguide.

[0228] Figure 16 A side view shows an example of a stack of waveguides with color filters for mitigating ghosting or crosstalk between waveguides. Figure 16 The eyepiece 1020 is similar to Figure 15The eyepiece, in addition to the presence of one or more of color filters 1024c, 1024b and 1028, 1026. Color filters 1024c and 1024b are configured to reduce the amount of light unintentionally coupled into waveguides 1020b and 1020a, respectively. Color filters 1028 and 1026 are configured to reduce the amount of image light unintentionally coupled into waveguides 1020b and 1020c, respectively.

[0229] Continue to refer to Figure 16 A pair of color filters 1026 disposed on the upper and lower main surfaces of waveguide 1020c can be configured to absorb image light 1032a, 1032b that may be unintentionally coupled into waveguide 1020c. In some embodiments, a color filter 1024c disposed between waveguides 1020c and 1020b is configured to absorb image light 1032c that is transmitted through coupled optical element 1022c but not coupled into waveguide 1020b. A pair of color filters 1028 disposed on the upper and lower main surfaces of waveguide 1020b are configured to absorb image light 1032a coupled into waveguide 1020b. A color filter 1024b disposed between waveguides 1020b and 1020a is configured to absorb image light 1032b transmitted through coupled optical element 710.

[0230] In some embodiments, the color filters 1026 on each main surface of waveguide 1020c are similar and configured to absorb light of the wavelengths of image lights 1032a, 1032b. In some other embodiments, the color filters 1026 on one main surface of waveguide 1020c may be configured to absorb light of the color of image light 1032a, and the color filters on the other main surface may be configured to absorb light of the color of image light 1032b. In any arrangement, the color filters 1026 may be configured to selectively absorb image lights 1032a, 1032b propagating through waveguide 1020c with total internal reflection. For example, when image lights 1032a, 1032b leave the TIR bounce of the main surfaces of waveguide 1020c, the image lights 1032a, 1032b contact the color filters 1026 on those main surfaces, and a portion of the image light is absorbed. Preferably, due to the selective absorption of image light 1032a and 1032b by color filter 1026, the propagation of coupled image light 1032c via TIR through waveguide 1020c is not significantly affected.

[0231] Similarly, multiple color filters 1028 can be configured as absorption filters that absorb the coupled image light 1032a propagating through waveguide 1020b via total internal reflection. As the image light 1032a exits the TIR bounce off the main surface of waveguide 1020b, it contacts the color filters 1028 on those main surfaces, and a portion of the image light is absorbed. Preferably, the absorption of the image light 1032a is selective and does not affect the propagation of the coupled image light 1032b, which also propagates through waveguide 1020b via TIR.

[0232] Continue to refer to Figure 16 Color filters 1024c and 1024b can also be configured as absorption filters. Color filter 1024c can be substantially transparent to the colors of image lights 1032a and 1032b, allowing image lights 1032a and 1032b to pass through color filter 1024c with almost no attenuation, while the colors of image light 1032c are selectively absorbed. Similarly, color filter 1024b can be substantially transparent to the colors of image light 1032a, allowing incident image light 1032a to pass through color filter 1024b with almost no attenuation, while the colors of image light 1032b are selectively absorbed. Figure 16 As shown, color filter 1024c can be disposed on the main surface (e.g., the upper main surface) of waveguide 1020b. Alternatively, color filter 1024c can be disposed on a separate substrate located between waveguides 1020c and 1020b. Similarly, color filter 1024b can be disposed on the main surface (e.g., the upper main surface) of waveguide 1020a. Alternatively, color filter 1024b can be disposed on a separate substrate located between waveguides 1020b and 1020a. It will be understood that color filters 1024c and 1024b can be perpendicularly aligned with a single pupil of the projector of the output image lights 1032a, 1032b, 1032c (as shown, in the orientation where the image lights 1032a, 1032b, 1022c propagate perpendicularly to the waveguide stack 1020).

[0233] In some embodiments, color filters 1026 and 1028 may have a one-way attenuation factor of less than about 10% (e.g., less than or equal to about 5%, less than or equal to about 2%, and greater than about 1%) to avoid significant undesirable absorption of light propagating through the thickness of waveguides 1020c, 1020b (e.g., light of the color of image light 1032a, 1032b propagating through waveguides 1020c, 1020b from the surrounding environment and / or other waveguides). Various embodiments of color filters 1024c and 1024b may be configured to have a low attenuation factor for the wavelength to be transmitted and a high attenuation factor for the wavelength to be absorbed. For example, in some embodiments, color filter 1024c may be configured to transmit greater than 80%, greater than 90%, or greater than 95% of incident light having the color of image light 1032a, 1032b, and absorb greater than 80%, greater than 90%, or greater than 95% of incident light having the color of image light 1032a. Similarly, the color filter 1024b can be configured to transmit more than 80%, more than 90%, or more than 95% of the incident light having the color of the image light 1032a, and absorb more than 80%, more than 90%, or more than 95% of the incident light having the color of the image light 1032b.

[0234] In some embodiments, color filters 1026, 1028, 1024c, and 1024b may include a color-selective absorbing material layer deposited on one or both surfaces of waveguides 1020c, 1020b, and / or 1020a. The color-selective absorbing material may include dyes, inks, or other light-absorbing materials such as metals, semiconductors, and dielectrics. In some embodiments, by utilizing these materials to form subwavelength gratings (e.g., non-diffractive gratings), the absorption of materials such as metals, semiconductors, and dielectrics can be color-selective. The grating may be made of plasma (e.g., gold, silver, and aluminum) or semiconductors (e.g., silicon, amorphous silicon, and germanium).

[0235] Color-selective materials can be deposited on a substrate using various deposition methods. For example, color-selective absorbing materials can be deposited on a substrate using jet deposition techniques (e.g., inkjet deposition). Inkjet deposition can be advantageous for depositing thin layers of color-selective absorbing materials. Because inkjet deposition allows the deposition to be positioned on selected regions of the substrate, it provides a high degree of control over the thickness and composition of the color-selective absorbing material layer, including providing non-uniform thickness and / or composition across the substrate. In some embodiments, the color-selective absorbing material deposited using inkjet deposition can have a thickness between about 10 nm and about 1 micrometer (e.g., between about 10 nm and about 50 nm, between about 25 nm and about 75 nm, between about 40 nm and about 100 nm, between about 80 nm and about 300 nm, between about 200 nm and about 500 nm, between about 400 nm and about 800 nm, between about 500 nm and about 1 micrometer, or any value within a range / subrange defined by any of these values). Controlling the thickness of the deposited layer of color-selective absorbing material can facilitate the creation of color filters with desired attenuation factors. Furthermore, layers of different thicknesses can be deposited in different portions of the substrate. Additionally, inkjet deposition can be used to deposit different compositions of the color-selective absorbing material in different portions of the substrate. Such variations in composition and / or thickness can advantageously allow for location-specific variations in absorption. For example, in waveguide regions where light transmission from the surrounding environment (to allow the viewer to see the surroundings) is unnecessary, the composition and / or thickness can be selected to provide high absorption or attenuation of a selected wavelength of light. Other deposition methods such as coating, spin coating, and spraying can be used to deposit color-selective absorbing materials onto the substrate.

[0236] Figure 17 It shows Figure 15 and 16 An example of a top view of a waveguide assembly. As shown, coupling optical elements 1022a, 1022b, and 1022c are spatially overlapping. Furthermore, waveguides 1020a, 1020b, and 1020c, along with their associated light distribution elements 730, 740, and 750 and associated output optical elements 800, 810, and 820, can be vertically aligned. The coupling optical elements 1022a, 1022b, and 1022c are configured to couple incident image light 1032a, 1032b, and 1032c into waveguides 1020a, 1020b, and 1020c, respectively. Figure 15 and 16 This allows image light to propagate through the TIR to the associated light distribution elements 730, 740, and 750.

[0237] Figure 18 It shows Figure 15 and 16Another example of a top view of a waveguide component. (As shown in...) Figure 17 In this configuration, coupling optical elements 1022a, 1022b, and 1022c are spatially overlapped, and waveguides 1020a, 1020b, and 1020c are vertically aligned. However, instead of the associated light distribution elements 730, 740, and 750 and associated output optical elements 800, 810, and 820 of each waveguide, OPE / EPE 1281, 1282, and 1283 are respectively combined. The coupling optical elements 1022a, 1022b, and 1022c are configured to couple incident image light 1032a, 1032b, and 1032c into waveguides 1020a, 1020b, and 1020c, respectively. Figure 15 and 16 This allows image light to propagate through TIR to the associated combination of OPE / EPE 1281, 1282, and 1283.

[0238] Although Figures 15 to 18 The diagram illustrates overlapping coupling optics for a single-pupil configuration of a display system; however, it will be understood that in some embodiments, the display system may have a dual-pupil configuration. In such a configuration, when utilizing three component colors, image light for two colors may have overlapping coupling optics, while image light for the third color may have laterally shifted coupling optics. For example, optical combiner 1050 ( Figure 11A , 12 13A-13B) and / or light reguiding structures 1080a, 1080c can be configured to guide image light through projection optics 1070, such that two colors of image light are incident on the directly overlapping area of ​​eyepiece 1020, while the other color of image light is incident on the laterally shifted area. For example, reflective surfaces 1052, 1054 ( Figure 11A The light can be angled such that the image light of one color follows a common optical path with the image light from the nanowire LED microdisplay 1030b, while the image light of another color follows a different optical path. In some embodiments, instead of having two light reguiding structures 1080a, 1080c... Figure 12 Instead, one of these light reguiding structures can be omitted, so that the light from only one of the microdisplays 1030a and 1030c is angled to provide a different optical path than the light emitted by the other two microdisplays.

[0239] Figure 19A A side view of an example eyepiece with a waveguide stack is shown, which has some overlap and some laterally shifted coupled optics. Figure 19A The eyepiece is similar to Figure 15The eyepiece, except that one of the coupled optics is laterally displaced relative to the other coupled optics. In the illustrated orientation of eyepiece 1020, where image light propagates vertically downwards along the page toward eyepiece 1020, coupled optics 1022a and 1022c are perpendicularly aligned with each other (e.g., along an axis parallel to the propagation direction of image light 1032a and 1032c) such that they spatially overlap each other as seen in a front view in the direction in which image light 1032a and 1032c propagates to coupled optics 1022a, 1022b and 1022c. As seen in the same front view (e.g., as seen in a top view of the illustrated orientation), coupled optics 1022b is laterally displaced relative to the other coupled optics 1022a and 1022c. Light for coupled optics 1022b exits to eyepiece 1020 through a different exit pupil than light for coupled optics 1022a and 1022c. It will be understood that the waveguide stack shown, including waveguides 1020a, 1020b, and 1020c, can be used instead. Figure 13A , 13B The single waveguide 1020a is shown in 14.

[0240] Continue to refer to Figure 19A The coupled optical element 1022c is configured to couple image light 1032c into waveguide 1020c, such that it propagates through waveguide 1020c through multiple total internal reflections between the upper and lower main surfaces of waveguide 1020c; the coupled optical element 1022b is configured to couple image light 1032b into waveguide 1020b, such that it propagates through waveguide 1020b through multiple total internal reflections between the upper and lower main surfaces of waveguide 1020b; and the coupled optical element 1022a is configured to couple image light 1032a into waveguide 1020a, such that it propagates through waveguide 1020a through multiple total internal reflections between the upper and lower main surfaces of waveguide 1020a.

[0241] The coupling optics 1022c are preferably configured to couple all incident light 1032c into the associated waveguide 1020c, while being transmissive for all incident light 1022a. On the other hand, image light 1032b can propagate to the coupling optics 1022b without needing to propagate through any other coupling optics. This may be advantageous in some embodiments because it allows the light most sensitive to the eye to be incident on the desired coupling optics without any loss or distortion associated with propagation through other coupling optics. Without being theoretically limited, in some embodiments, image light 1032b is green light, to which the human eye is more sensitive. It will be understood that while waveguides 1020a, 1020b, and 1020c are shown arranged in a specific order, in some embodiments, the order of waveguides 1020a, 1020b, and 1020c may be different.

[0242] It will be understood that, as discussed herein, the coupling optics 1022c on top of coupling optics 1022a may not have perfect selectivity. Some of the image light 1032a may be undesirably coupled into waveguide 1020c by coupling optics 1022c; and some of the image light 1032c may transmit through coupling optics 1022c, after which image light 1032c may strike coupling optics 1020a and be coupled into waveguide 1020a. As discussed herein, such undesirable coupling can be seen as ghosting or crosstalk.

[0243] Figure 19B A color filter with the ability to mitigate ghosting or crosstalk between waveguides is shown. Figure 19A A side view of an example eyepiece. Specifically, color filters 1024c and / or 1026 are added. Figure 19A In the structure shown, as illustrated, the coupling optical element 1022c may unintentionally couple a portion of the image light 1032a into the waveguide 1020c. Alternatively, a portion of the image light 1032c may undesirably transmit through the coupling optical element 1022c, after which the image light may be unintentionally coupled by the coupling optical element 1022a.

[0244] To mitigate unintentional coupling of image light 1032a propagating through waveguide 1022c, an absorptive color filter 1026 can be provided on one or both main surfaces of waveguide 1022c. The absorptive color filter 1026 can be configured to absorb the color of the unintentionally coupled image light 1032a. As shown, the absorptive color filter 1026 is positioned along the general propagation direction of the image light through waveguide 1020c. Therefore, the absorptive color filter 1026 is configured to absorb image light 1032a when it reflects off one or both of the main surfaces of waveguide 1020c and propagates through waveguide 1020c via TIR and contacts the absorptive color filter 1026.

[0245] Continue to refer to Figure 19B To mitigate the propagation of image light 1032c through the coupled optical element 1022c without being coupled to it, an absorptive color filter 1024c can be provided in front of the coupled optical element 1022a. The absorptive color filter 1024c is configured to absorb light of the color of the image light 1032c to prevent that light from propagating to the coupled optical element 1022a. Although shown between waveguides 1020c and 1020b, in some other embodiments, the absorptive color filter 1024c may be disposed between waveguides 1020b and 1020a. It will be understood that further details regarding the composition, formation, and characteristics of the absorptive color filters 1024c and 1026 are provided in [the relevant section]. Figure 16 Provided in the discussion.

[0246] It will also be understood that, Figure 16 and 19B In the illustrated embodiment, if one or more of the coupled optical elements 1022a, 1022b, 1022c have sufficiently high selectivity for the color of light intended to be coupled into the associated waveguides 1020a, 1020b, 1022c, one or more of the color filters 1026, 1028, 1024c, and 1024b can be omitted.

[0247] Figure 20A It shows Figure 19A and 19B An example of a top view of the eyepiece. As shown, the coupling optical elements 1022a and 1022c are spatially overlapped, while the coupling optical unit 1022b is laterally shifted. Additionally, waveguides 1020a, 1020b, and 1020c, along with their associated light distribution elements 730, 740, and 750 and associated output optical elements 800, 810, and 820, can be vertically aligned. The coupling optical elements 1022a, 1022b, and 1022c are configured to couple incident image light 1032a, 1032b, and 1032c into waveguides 1020a, 1020b, and 1020c, respectively. Figure 15and 16 This allows image light to propagate through the TIR to the associated light distribution elements 730, 740, and 750.

[0248] Figure 20B It shows Figure 19A and 19B Another example of a top view of a waveguide component. (As shown in...) Figure 20A In this configuration, the coupled optical elements 1022a and 1022c are spatially overlapped, laterally shifted, and the waveguides 1020a, 1020b, and 1020c are vertically aligned. However, instead of the associated light distribution elements 730, 740, and 750 and the associated output optical elements 800, 810, and 820 of each waveguide, OPE / EPE 1281, 1282, and 1283 are respectively combined. The coupled optical elements 1022a, 1022b, and 1022c are configured to couple incident image light 1032a, 1032b, and 1032c into waveguides 1020a, 1020b, and 1020c, respectively. Figure 15 and 16 This allows image light to propagate through TIR to the associated combination of OPE / EPE1281, 1282, and 1283.

[0249] Now for reference Figure 21 It will be understood that re-bouncing of coupled light can occur undesirably in a waveguide. Re-bouncing occurs when coupled light propagating along the waveguide strikes the coupled optics a second or subsequent time after the initial coupled incident. Re-bouncing can cause a portion of the coupled light to be undesirably coupled out and / or absorbed by the material of the coupled optics. Coupling out and / or light absorption can undesirably lead to a reduction in the overall coupling efficiency and / or uniformity of the coupled light.

[0250] Figure 21 A side view of an example of re-bounce in waveguide 1030a is shown. As shown, image light 1032a is coupled into waveguide 1030a via coupling optics 1022a. Coupling optics 1022a redirects image light 1032a such that it generally propagates through the waveguide in direction 1033. Re-bounce can occur when the coupled image light is internally reflected or bounced off the main surface of waveguide 1030a opposite to coupling optics 1022a and incident on coupling optics 1022a or undergoes a second bounce (re-bounce) at coupling optics 1022a. The distance between two adjacent bounces on the same surface of waveguide 1030a is represented by spacing 1034.

[0251] Without being limited by theory, it will be understood that the coupling optical element 1022a can behave symmetrically; that is, it can redirect incident light so that the incident light propagates through the waveguide at a TIR angle. However, light incident on the diffractive optical element at a TIR angle (e.g., upon re-bouncing) may also be coupled out. Additionally or alternatively, in embodiments where the coupling optical element 1022a is coated with a reflective material, it will be understood that reflection of light from a material layer such as a metal may also involve partial absorption of the incident light, since reflection may involve the absorption and emission of light from the material. Therefore, light coupling out and / or absorption may undesirably cause loss of coupled light. Thus, re-bouncing light may result in a significant loss compared to light that interacts with the coupling optical element 1022a only once.

[0252] In some embodiments, the coupling element is configured to mitigate coupled image light loss due to re-bouncing. Typically, re-bouncing of coupled light occurs toward the end 1023 of the coupling optics 1022a in the propagation direction 1033 of the coupled light. For example, if the spacing 1034 for the light is short enough, light coupled at the end of the coupling optics 1022a opposite to the end 1023 can be re-bounced. To avoid such re-bouncing, in some embodiments, the coupling optics 1022a is truncated at the propagation direction end 1023 to reduce the width 1022w of the coupling optics 1022a along which re-bouncing may occur. In some embodiments, the truncation may be a complete truncation of all structures of the coupling optics 1022a (e.g., metallization and diffraction gratings). In some other embodiments, for example, where the coupling optical element 1022a includes a metallized diffraction grating, a portion of the coupling optical element 1022a at the propagation direction end 1023 may not be metallized, such that the propagation direction end 1023 of the coupling optical element 1022a absorbs less bounced light and / or couples out less bounced light with lower efficiency. In some embodiments, the diffraction region of the coupling optical element 1022a may have a width along the propagation direction 1033 shorter than its length perpendicular to the propagation direction 1033, and / or may be sized and shaped such that a first portion of the image light 1032a is incident on the coupling optical element 1022a, and a second portion of the beam is incident on the waveguide 1030a without incident on the coupling optical element 1022a. Although the waveguide 1032a and the optical coupling optical element 1022a are shown separately for clarity, it will be understood that bounce and the strategies discussed for reducing bounce can be applied to any coupling optical element disclosed herein. It will also be understood that the spacing 1034 is related to the thickness of waveguide 1030a (a larger thickness results in a larger spacing 1034). In some embodiments, the thickness of individual waveguides can be selected to set the spacing 1034 so that rebouncing does not occur. Further details regarding rebouncing mitigation can be found in U.S. Provisional Application No. 62 / 702,707, filed July 24, 2018, the entire disclosure of which is incorporated herein by reference.

[0253] Figures 22A to 23C An example top view of an eyepiece with coupling optics configured to reduce bounce is shown. Coupling optics 1022a, 1022b, and 1022c are configured to couple light such that they are oriented in the propagation direction toward associated light distribution elements 730, 740, and 750. Figures 22A-22C ) or combinations of OPE / EPE 1281, 1282, 1283 ( Figures 23A-23CPropagation. As shown, the coupled optical elements 1022a, 1022b, and 1022c can have a shorter dimension along the propagation direction and a longer dimension along the transverse axis. For example, the coupled optical elements 1022a, 1022b, and 1022c can each be rectangular in shape, having a shorter side along the axis of the propagation direction and a longer side along the orthogonal axis. It will be understood that the coupled optical elements 1022a, 1022b, and 1022c can have other shapes (e.g., orthogonal, hexagonal, etc.). Furthermore, in some embodiments, different coupled optical elements among the coupled optical elements 1022a, 1022b, and 1022c can have different shapes. Moreover, preferably, as shown, non-overlapping coupled optical elements can be positioned such that they are not in the propagation direction of other coupled optical elements. For example, as... Figure 22A , 22B As shown in 23A and 23B, non-overlapping coupled optical elements can be arranged in a straight line along an axis that intersects (e.g., is orthogonal) the axis of the propagation direction.

[0254] It will be understood that, in addition to the overlap of coupled optical elements 1022a, 1022b, and 1022c, Figures 22A to 22C The waveguide components are similar. For example, Figure 22A Coupled optical elements 1022a, 1022b, and 1022c without overlap are shown. Figure 22B The overlapping coupled optical elements 1022a and 1022c and the non-overlapping coupled optical element 1022b are shown. Figure 22C The overlap between all coupled optical elements 1022a, 1022b, and 1022c is shown.

[0255] Besides the overlap of coupled optical elements 1022a, 1022b, and 1022c, Figures 23A to 23C The waveguide components are also similar. Figure 23A Coupled optical elements 1022a, 1022b, and 1022c without overlap are shown. Figure 23B The overlapping coupled optical elements 1022a and 1022c and the non-overlapping coupled optical element 1022b are shown. Figure 22C The overlap between all coupled optical elements 1022a, 1022b, and 1022c is shown.

[0256] Now for reference Figure 24A As will be understood, nanowire LED microdisplays possess high elongation, which presents challenges for efficient light utilization. As discussed herein, nanowire LED microdisplays may include multiple individual light emitters. Each of these light emitters may have a large angular emission profile, such as a Lambertian or near-Lambertian emission profile. Undesirably, not all of this light can be captured and directed to the eyepiece of the display system.

[0257] Advantageously, as discussed herein, nanowire LEDs can have a narrower angular emission profile than planar LEDs, for example, due to their periodic array structure as photonic crystal materials. Therefore, nanowire LEDs can have more directional light output compared to typical planar microLEDs. In some embodiments, the directivity can be independent of the pixel pitch and can be customized by adjusting nanowire microLED parameters such as, but not limited to, nanowire material, dopants, size, refractive index, etc. Thus, as discussed herein, nanowire LED microdisplays can advantageously omit optics for directing light emitted from the nanowire LEDs. As discussed herein, the absence of such optics can have the advantage of simplifying the display system and also increasing light output. However, in some embodiments, it may be desirable to further manipulate the angular emission profile and / or direction of the output light.

[0258] In some embodiments, various optical structures can be used to further narrow the angular diffusion of light emitted by nanowire LEDs. Figure 24A An example of the angular emission profiles of light emitted by the individual light emitter 1044 of the nanowire LED microdisplay 1032 and captured by the projection optics 1070 is shown in magnified form. The nanowire LED microdisplay 1032 shown can correspond to any emitting microdisplay disclosed herein, including nanowire LED microdisplays 1032a, 1032b, 1032c. As shown, the size of the projection optics 1070 can be determined such that it will capture light having an angular emission profile 1046. However, the angular emission profile 1046 in the light emitter 1044 can be significantly larger; not all light emitted by the light emitter 1044 can be incident on the projection optics 1070, nor necessarily at an angle at which light can propagate into and pass through the projection optics 1070. Therefore, some of the light emitted by the light emitter 1044 may be undesirably “wasted” because it is not captured and ultimately relayed to the user’s eye to form an image. If more light emitted by the light emitter 1040 ends up reaching the user's eyes, this could cause the image to appear darker than expected.

[0259] In some embodiments, one strategy for capturing more light emitted by the light emitter 1040 is to increase the size of the projection optics 1070 to increase the numerical aperture of the projection optics 1060 that captures light. Additionally or alternatively, the projection optics 1070 may also be formed of a high refractive index material (e.g., having a refractive index greater than 1.5) that also facilitates light collection. In some embodiments, the projection optics 1070 may utilize a lens whose size is determined to capture a desired high proportion of the light emitted by the light emitter 1044. In some embodiments, the projection optics 1070 may be configured to have an elongated exit pupil, for example, to emit light with a diameter greater than that of the light emitted by the light emitter 1044. Figures 22A-23C The beams of light with similar cross-sectional profiles to the coupling optical elements 1022a, 1022b, and 1022c. For example, the projection optics 1070 can be used in a beam with a similar cross-sectional profile to the coupling optical elements 1022a, 1022b, and 1022c. Figures 22A-23C The elongated dimensions of the coupling optical elements 1022a, 1022b, and 1022c are extended. Unrestricted by theory, such elongated coupling optical elements 1022a, 1022b, and 1022c can improve the span mismatch between the nanowire LED microdisplay and the eyepiece 1020. Figures 22A-23C In some embodiments, the eyepiece 1020 (e.g., Figure 11A and 12 The thickness of the waveguide (-23C) can be selected to increase the percentage of effectively captured light, for example, by increasing the bounce spacing to reduce bounce, as discussed in this paper.

[0260] In some embodiments, one or more optical collimators can be used to reduce or narrow the angular emission profile of the light from the light emitter 1044. Therefore, more light emitted by the light emitter 1044 can be captured by the projection optics 1070 and relayed to the user's eye, advantageously increasing the brightness of the image and the efficiency of the display system. In some embodiments, the optical collimator can allow the light collection efficiency of the projection optics (the percentage of light emitted by the light emitter 1044 that is captured by the projection optics) to reach values ​​of 80% or more, 85% or more, or 90% or more, including about 85-95% or 85-90%. Additionally, the angular emission profile of the light from the light emitter 1044 can be reduced to 50° or less, 40° or less, or 30° or less. In some embodiments, the reduced angular emission profile can be in the range of about 30-60°, 30-50°, or 30-40°. It will be understood that the light from the light emitter 1044 can form a cone shape, with the light emitter 1046 at the apex of the cone. An angular emission profile refers to the angle formed by the side of the cone, where the associated light emitter 1044 is located at the apex of the angle (as seen in a cross-section taken along a plane extending through the middle of the cone and including the apex of the cone).

[0261] Figure 24B An example of narrowing the angular emission profile using an array of optical collimators is illustrated. As shown, a nanowire LED microdisplay 1032 includes an array of light emitters 1044 that emit light having an angular emission profile 1046. An array 1300 of optical collimators 1302 is positioned in front of the light emitters 1044. In some embodiments, each light emitter 1044 is paired one-to-one with an associated optical collimator 13021 (one optical collimator 1301 for each light emitter 104). Each optical collimator 1302 redirects the incident light from the associated light emitter 1044 to provide a narrowed angular emission profile 1047. Thus, the relatively large angular emission profile 1046 is narrowed to a smaller angular emission profile 1047.

[0262] In some embodiments, the optical collimator 1302 and the array 1300 may be Figure 12 and 13A It is part of the light redirection structures 1080a and 180c. Therefore, the light collimator 1302 can narrow the angular emission profile of the light emitter 1044 and also redirect the light so that it propagates at an appropriate angle into the optical combiner 1050 to define multiple optical paths and associated multiple exit pupils. It will be understood that by properly shaping the light collimator 1302, light can be redirected in a specific direction.

[0263] Preferably, the optical collimator 1302 is positioned adjacent to the optical emitter 1044 to capture most of the light emitted by the optical emitter 1044. In some embodiments, a gap may exist between the optical collimator 1302 and the optical emitter 1044. In some other embodiments, the optical collimator 1302 may contact the optical emitter 1044. It will be understood that the angular emission profile 1046 may form a wide light cone. Preferably, all or most of the light cone from the optical emitter 1044 is incident on a single associated optical collimator 1302. Therefore, in some embodiments, each optical emitter 1044 has a smaller light-receiving surface (occupies a smaller area) than the associated optical collimator 1302. In some embodiments, each optical emitter 1044 has a width smaller than the spacing between adjacent far-light emitters 1042.

[0264] Advantageously, the optical collimator 1302 can increase light utilization efficiency and also reduce crosstalk between adjacent light emitters 1044. It will be understood that crosstalk between light emitters 1044 can occur when light from an adjacent light emitter is captured by an optical collimator 1302 that is not associated with that adjacent light emitter. This captured light may propagate to the user's eye, thus providing incorrect image information for a given pixel.

[0265] refer to Figure 24A and 24BThe size of the light beam captured by the projection optics 1070 may affect the size of the light beam leaving the projection optics 107. For example... Figure 24A As shown, without using an optical collimator, the emitted beam can have a relatively large width of 1050. For example... Figure 24B As shown, when using the optical collimator 1302, the emitted beam can have a smaller width 1052. Therefore, in some embodiments, the optical collimator 1302 can be used to provide the desired beam size for coupling into the eyepiece. For example, the amount by which the optical collimator 1302 narrows the angular emission profile 1046 can be selected at least in part based on the size of the coupling optics in the eyepiece, into which light output from the projection optics 1070 is guided.

[0266] It will be understood that the optical collimator 1302 can take various forms. For example, in some embodiments, the optical collimator 1302 may be a microlens or a small lens. As discussed herein, each microlens preferably has a width greater than the width of the associated light emitter 1044. The microlens may be formed of a curved transparent material, such as glass or a polymer, including photoresists and resins, such as epoxy resins. In some embodiments, the optical collimator 1302 may be a nanolens, for example, a diffraction grating. In some embodiments, the optical collimator 1302 may be a metasurface and / or a liquid crystal grating. In some embodiments, the optical collimator 1302 may take the form of a reflective trap.

[0267] It will be understood that different light collimators 1302 can have different sizes and / or shapes depending on the wavelength or color of the light emitted by the associated light emitter 1044. Therefore, for a full-color nanowire LED microdisplay, array 1300 may include multiple light collimators 1302 having different sizes and / or shapes depending on the color of the light emitted by the associated light emitter 1044. In embodiments where the nanowire LED microdisplay is a monochrome microdisplay, array 1300 can be simplified, where each of the light collimators 1302 in the array is configured to redirect light of the same color. For such a monochrome microdisplay, in some embodiments, the light collimators 1302 may be similar across array 1300.

[0268] Continue to refer to Figure 24BAs discussed herein, the optical collimator 1302 may have a one-to-one association with the optical emitter 1044. For example, each optical emitter 1044 may have a discrete associated optical collimator 1302. In some other embodiments, the optical collimators 1302 may be elongated such that they extend across multiple optical emitters 1044. For example, in some embodiments, the optical collimators 1302 may be elongated into the page and extend in front of a row of multiple optical emitters 1044. In some other embodiments, a single optical collimator 1302 may extend across a column of optical emitters 1044. In other embodiments, the optical collimators 1302 may include stacked columns and / or rows of lens structures (e.g., nanolens structures, microlens structures, etc.).

[0269] As described in this article, the optical collimator 1302 can take the form of a reflective trap. Figure 25A An example side view of a tapered reflective trap array for guiding light to a projection optics is shown. As shown, the light collimator array 1300 may include a substrate 1301 in which a plurality of light collimators 1302 in the form of reflective traps may be formed. Each trap may include at least one light emitter 1044 that can emit light having a Lambertian angle emission profile 1046. The reflective walls 1303 of the traps of the light collimators 1302 are tapered and reflect the emitted light such that the light exits from the trap with a narrower angle emission profile 1047. As shown, the reflective walls 1303 may be tapered such that the cross-sectional size increases with distance from the light emitter 1044. In some embodiments, the reflective walls 1303 may be curved. For example, the side 1303 may have the shape of a compound parabolic concentrator (CPC).

[0270] Now for reference Figure 25B An example side view of an asymmetric conical reflector is shown. As discussed herein, for example, such as... Figure 12 and 13A As shown, it may be desirable to use the optical collimator 1302 to direct light in a specific direction that is not perpendicular to the surface of the light emitter 1044. In some embodiments, such as... Figure 25BAs observed in the side view shown, the optical collimator 1302 can be asymmetrical, wherein the upper side 1303a forms an angle with the surface of the light emitter 1044 different from that of the lower side 1303b (e.g., a larger angle); for example, the angles of the reflectors 1303a, 1303b relative to the light emitter 1044 can be different on different sides of the optical collimator 1302 in order to guide light in a specific non-linear direction. Therefore, as shown, light exiting the optical collimator 1302 can generally propagate in a direction 1048 that is not perpendicular to the surface of the light emitter 1044. In some other embodiments, in order to guide light in direction 1048, the taper of the upper side 1303a can be different from that of the lower side; for example, the upper side 1303a can be spread out to a greater extent than the lower side 1303b.

[0271] Continue to refer to Figure 25B The substrate 1301 can be formed from a variety of materials with sufficient mechanical integrity to maintain the desired shape of the reflector wall 1303. Examples of suitable materials include metals, plastics, and glass. In some embodiments, the substrate 1301 can be a sheet of material. In some embodiments, the substrate 1301 is a continuous single sheet of material. In some other embodiments, the substrate 1301 can be formed by joining two or more pieces of material together.

[0272] The reflective wall 1303 can be formed in the substrate 1301 by various methods. For example, the wall 1303 can be formed into a desired shape by machining the substrate 1301 or otherwise removing material to define the wall 1303. In some other embodiments, the wall 1303 can be formed during the formation of the substrate 1301. For example, the wall 1303 can be molded into the substrate 1301 when the substrate 1301 is molded into its desired shape. In some other embodiments, the wall 1303 can be defined by rearranging material after the formation of the body 2200. For example, the wall 1303 can be defined by embossing.

[0273] Once the outline of the walls 1303 is formed, they can undergo further processing to create a surface with the desired reflectivity. In some embodiments, the surface of the substrate 1301 may itself be reflective, for example, where the body is formed of a reflective metal. In such cases, further processing may include smoothing or polishing the inner surface of the walls 1303 to increase its reflectivity. In some other embodiments, the inner surface of the reflector 2110 may be lined with a reflective coating, for example, by a vapor deposition process. For example, the reflective layer may be formed by physical vapor deposition (PVD) or chemical vapor deposition (CVD).

[0274] It will be understood that the position of the light emitter relative to the associated optical collimator can affect the direction of the light emitted from the optical collimator. For example, Figures 26A to 26C This shows that Figures 26A to 26C An example is shown of the optical path differences for light emitters at different locations relative to the centerline of overlapping associated optical collimators. For example... Figure 26A As shown, another nanowire LED microdisplay 30 has multiple light emitters 1044a, each with an associated light collimator 1302 that facilitates the output of light with a narrowed angular emission profile 1047. Light passes through a projection optics 1070 (represented as a simple lens for ease of illustration), which converges the light from each light emitter 1044a onto region 1402a.

[0275] Continue to refer to Figure 26A In some embodiments, each of the optical collimators 1302 may be symmetrical and may have a centerline extending along the axis of symmetry of the optical collimator. In the illustrated configuration, the light emitter 1044a is disposed on the centerline of each of the optical collimators 1302.

[0276] Now for reference Figure 26B The light emitter 1044b is offset by a distance 1400 from the centerline of its corresponding collimator 1302. This offset causes the light from the light emitter 1044b to take a different path through the collimator 1302, which outputs light from the light emitter 1044b with a narrowed angular emission profile 1047b. The projection optics 1070 then converges the light from the light emitter 1044b onto region 1402b, which is offset relative to region 1402a where the light from the light emitter 1044a converges.

[0277] Now for reference Figure 26C The diagram illustrates a light emitter 1046c offset from light emitters 1044a and 1044b. This offset causes light from light emitter 1044c to take a different path than light from light emitters 1044a and 1044b through optical collimator 1302. This causes optical collimator 1302 to output light from light emitter 1044c with a narrowed angular emission profile, which takes a different path than light from light emitters 1044a and 1044b to projection optics 1070. Finally, projection optics 1070 converges the light from light emitter 1044c onto region 1402c, which is offset relative to regions 1402a and 1402b.

[0278] refer to Figures 26A to 26CEach set of three light emitters 1044a, 1044b, and 1044c can share a common optical collimator 1302. In some embodiments, the microdisplay 1030 can be a full-color microdisplay, and each light emitter 1044a, 1044b, and 1044c can be configured to emit light of different component colors. Advantageously, in some embodiments, the offset regions 1402a, 1402b, and 1402c can correspond to the coupled optical elements of the waveguide. For example, regions 1402a, 1402b, and 1402c can respectively correspond to Figure 11A and 12 The optical elements 1022a, 1022b, and 1022c are coupled into the light. Therefore, the offset orientation of the light collimator 1302 and the light emitters 1044a, 1044b, and 1044c can provide an advantageously simple three-pupil projection system 1010 using a full-color nanowire LED microdisplay.

[0279] As described in this article, the optical collimator 1302 can also take the form of a nanolens. Figure 27 An example side view of a single light emitter 1044 of a nanowire LED microdisplay having an array 1300 of overlying collimators 1302 that serve as nanolenses is shown. As discussed herein, each of the single light emitters 1044 may have an associated collimator 1302. The collimator 1302 redirects light from the light emitter 1044 to narrow the large-angle emission profile 1046 of the light emitter 1044, so as to output light with a narrowed angular emission profile 1047.

[0280] Continue to refer to Figure 27 In some embodiments, the optical collimator 1302 may be a grating structure. In some embodiments, the optical collimator 1302 may be a grating formed by alternative elongated discrete extensions (e.g., lines) of materials with different refractive indices. For example, the extensions of material 1306 may extend into and out of the page and may be formed in and separated from the material of substrate 1308. In some embodiments, the elongated extensions 1306 of the material may have a subwavelength width and pitch (e.g., a width and pitch smaller than the wavelength of light received by the optical collimator 1302 from the associated light emitter 1044). In some embodiments, the pitch 1304 may be 30-300 nm, the grating depth may be 10-1000 nm, the refractive index of the material forming substrate 1308 may be 1.5-3.5, and the refractive index of the material forming grating features 1306 may be 1.5-2.5 (and different from the refractive index of the material forming substrate 1308).

[0281] The grating structure shown can be formed by various methods. For example, the substrate 1308 can be etched or nanoimprinted to define trenches, and the trenches can be filled with a material having a different refractive index than the substrate 1308 to form grating feature 1306.

[0282] Advantageously, nanolens arrays can offer a variety of benefits. For example, the light-collecting efficiency of the nanolenses can be very high, for example, 80-95%, including 85-90%, with excellent reduction in angular emission profile, for example, to 30-40° (from 180°). Additionally, low levels of crosstalk can be achieved because each of the nanolens collimators 1302 can have physical dimensions and characteristics (e.g., pitch, depth, refractive index of the materials forming substrates 1306 and 1308) selected to act on light of a specific color and possibly a specific angle of incidence, while preferably providing a high extinction ratio (for wavelengths of other colors of light). Furthermore, the nanolens array can have a flat profile (e.g., formed on a flat substrate), which can facilitate integration with microdisplays that may be flat panels, and can also facilitate fabrication and provide high reproducibility and accuracy when forming the nanolens array. For example, highly reproducible trench forming and deposition processes can be used to form each nanolens. Moreover, these processes allow variations between the nanolenses in the array to be easier and more reproducible than variations typically achieved when forming curved lenses with similar variations.

[0283] Now for reference Figure 28 The image shows a perspective view of an example of a nanowire LED microdisplay 1030. It will be understood that the light collimator array 1300 advantageously allows light emitted from the microdisplay to be routed as desired. Therefore, in some embodiments, the light emitters of the full-color microdisplay can be organized as desired, for example, to facilitate fabrication or implementation in a display device. In some embodiments, light emitters 1044 can be arranged in rows or columns 1306a, 1306b, 1306c. Each row or column may include light emitters 1044 configured to emit light of the same component color. In displays utilizing three component colors, groups of three rows or columns may exist, repeating across the microdisplay 1030. It will be understood that in the case of utilizing more component colors, each repeating group may have that number of rows or columns. For example, in the case of utilizing four component colors, each group may have four rows or four columns, where one row or column is formed by light emitters configured to emit light of a single component color.

[0284] In some embodiments, rows or columns may be repeated to increase the number of light emitters for a particular component color. For example, light emitters for some component colors may occupy multiple rows or columns. This can be beneficial for color balance and / or can be used to address different aging or reductions in light emission intensity over time.

[0285] Continue to refer to Figure 28 Each light emitter 1044 may extend along a specific axis (e.g., along the y-axis as shown); that is, each light emitter has a length along a specific axis that is longer than the width of the light emitter. Additionally, a group of light emitters configured to emit light of the same component color may be arranged in lines 1306a, 1306b, or 1306c (e.g., rows or columns) extending along an axis (e.g., the x-axis) that intersects (e.g., is orthogonal) the extension axis of the light emitters 1044. Thus, in some embodiments, light emitters 1044 of the same component color form lines 1306a, 1306b, or 1306c of light emitters, wherein the lines extend along a first axis (e.g., the x-axis), and wherein individual light emitters 1046 within the lines extend along a second axis (e.g., the y-axis).

[0286] Conversely, it will be understood that full-color microdisplays typically comprise subpixels for each component color, with the subpixels arranged in groups in a particularly close spatial orientation, where these groups are reproduced across the entire array. Each group of subpixels can form a pixel in an image. In some cases, the subpixels extend along an axis, and rows or columns of subpixels having the same component color extend along that same axis. It will be understood that such an arrangement allows each group of subpixels to be positioned close together, which can be beneficial for image quality and pixel density. However, in Figure 28 In the arrangement shown, due to the elongated shape of the light emitter 1044, the subpixels of different component colors are relatively far apart; that is, due to the elongated shape of the light emitter of line 1306b, the spacing between light emitters 1306a and 1306c is greater than that between adjacent light emitters of a given light emitter line, so the light emitter of line 1306a is relatively far apart from the light emitter of line 1306c. While it might be expected to provide unacceptably poor image quality if the image formed on the surface of the microdisplay 1030 were directly relayed to the user's eye, the use of the light collimator array 1300 advantageously allows light of different colors to be routed as desired to form a high-quality image. For example, light of each component color can be used to form a separate monochrome image, and then the separate monochrome image is routed to an eyepiece (such as eyepiece 1020, e.g., Figure 11A and 12 -14)) and combine them in the eyepiece.

[0287] refer to Figure 27 and 28In some embodiments, each of the light emitters 1044 may have an associated optical collimator 1302. In some other embodiments, each line 1306a, 1306b, 1306c of the plurality of light emitters 1044 may have a single associated optical collimator 1302. This single associated optical collimator 1302 may extend substantially across the entire associated line 1306a, 1306b, or 1306c. In some other embodiments, the associated optical collimator 1302 may be elongated and extend over the plurality of light emitters 1044 forming part of the associated line 1306a, 1306b, or 1306c, and a plurality of similar optical collimators 1302 may be provided along each of the associated lines.

[0288] It will be understood that the optical collimator 1302 can be used to guide light along different optical paths to form a multi-pupil projection system. For example, the optical collimator 1302 can guide light of different component colors to two or three regions for optical coupling.

[0289] Figure 29 An example of a wearable display system is shown, which has features for forming a multi-pupil projection system 1010. Figure 28 A full-color nanowire LED microdisplay 1030 is provided. In the illustrated embodiment, the full-color nanowire LED microdisplay 1030 emits light of three component colors and forms a three-pupil projection system 1010. The projection system 1010 has three exit pupils through which image light 1032a, 1032b, and 1032c of different component colors propagate to three laterally shifted light-coupled optical elements 1022a, 1022b, and 1022c of the eyepiece 1020, respectively. The eyepiece 1020 then relays the image light 1032a, 1032b, and 1032c to the user's eye 210.

[0290] The emission microdisplay 1030 includes an array of light emitters 1044, which can be subdivided into monochromatic light emitters 1044a, 1044b, and 1044c that respectively emit image light 1032a, 1032b, and 1032c. It will be understood that the light emitters 1044 emit image light with a wide-angle emission profile 1046. The image light propagates through an array of light collimators 1300, which reduces the angular emission profile to a narrowed angular emission profile 1047.

[0291] Furthermore, the optical collimator array 1300 is configured to redirect the image light (image light 1032a, 1032b, 1032c) such that the image light is incident on the projection optics 1070 at an angle that causes the projection optics 1070 to output image light, and that the image light propagates to the appropriate coupling optical elements 1022a, 1022b, 1022c. For example, the optical collimator array 1300 is preferably configured to: redirect image light 1032a such that it propagates through the projection optics 1070 and is incident on the coupling optical element 1022a; redirect image light 1032b such that it propagates through the projection optics 1070 and is incident on the coupling optical element 1022b; and redirect image light 1032c such that it propagates through the projection optics 1070 and is incident on the coupling optical element 1022c.

[0292] Because different light emitters 1044 can emit light of different wavelengths and may need to be redirected to different directions to reach appropriate coupling optical elements, in some embodiments, the optical collimators associated with different light emitters 1044 can have different physical parameters (e.g., different pitches, different widths, etc.). Advantageously, using flat nanolenses as optical collimators facilitates the formation of optical collimators whose physical properties vary across the optical collimator array 1300. As described herein, nanolenses can be formed using patterning and deposition processes, which facilitates the formation of structures with different pitches, widths, etc., across the substrate.

[0293] Refer again Figure 24A It will be understood that the display system shown illustrates a single nanowire LED microdisplay, and omits the optical combiner 1050. Figure 11A and 12 -13B). In embodiments utilizing optical combiner 1050, reflective surfaces 1052, 1054 in optical combiner 105 ( Figure 11A , 12 -13B and 30B) are preferably specular reflectors, and the light from the light emitter 1044 is expected to retain its large angular emission profile after reflection from the reflective surfaces 1051 and 1054. Therefore, when using the optical combiner 1050, regarding Figure 24A The problem of wasted light, as shown, exists similarly.

[0294] Now for reference Figure 30A An example of a wearable display system with nanowire LED microdisplays and an associated array of optical collimators is shown. Figure 30AAdditional details are shown regarding the interaction between the coupling optics of the light emitter 1044, the light collimator 1302, and the eyepiece 1020. The display system includes a microdisplay 1030b, which in some embodiments may be a panchromatic microdisplay. In some other embodiments, the microdisplay 1030b may be a monochrome microdisplay and may be integrated with an optional optical combiner 1050 (such as...). Figure 30C Additional monochrome microdisplays (not shown) are provided on different surfaces of the (shown).

[0295] Continue to refer to Figure 30A The microdisplay 1030b includes an array of light emitters 1044, each emitting light with a wide-angle emission profile (e.g., a Lambertian angle emission profile). Each light emitter 1044 has an associated dedicated collimator 1302 that effectively narrows the angle emission profile to a narrowed angle emission profile 1047. The light beam 1032b with the narrowed angle emission profile passes through a projection optics 1070, which projects or converges those beams onto a coupling optics element 1022b. It will be understood that the light beam 1032b has a specific cross-sectional shape and size 1047a. In some embodiments, when the light beam 1032b is incident on the coupling optics element 1022b, the coupling optics element 1022b has a size and shape that substantially matches or is larger than the cross-sectional shape and size of the light beam 1032b. Therefore, in some embodiments, the size and shape of the coupling optics 1022b can be selected based on the profile size and shape of the beam 1032b incident on the coupling optics 1022b. In some other embodiments, the size and shape of the coupling optics 1022b can be determined using other factors (rebound mitigation, or the angle or field of view supported by the coupling optics 1022b), and the collimator 1302 can be configured (e.g., sized and shaped) to provide a beam 1032b with a profile of appropriate size and shape, preferably completely or almost completely surrounded by the size and shape of the coupling optics 1022b. In some embodiments, the physical parameters for the collimator 1302 and the coupling optics 1022b can be modified together to provide efficient light utilization in conjunction with other desired functions (e.g., rebound mitigation, support for a desired field of view, etc.). Advantageously, the aforementioned optical collimation provided by the optical collimator 1302, and the matching of the cross-sectional size and shape of the beam 1032b with the size and shape of the coupled optical element 1022b, allow the coupled optical element 1022b to capture most of the incident beam 1032b. The coupled light then propagates through the waveguide 1020b and is coupled out to the eye 210.

[0296] In some embodiments, the light collimator 1302 is a microlens directly disposed on and surrounding the associated light emitter 1044. In some embodiments, adjacent microlenses 1302 are in near contact with each other or in direct contact. It will be understood that light from the light emitter 1044 can fill the associated microlens 1302, thereby effectively magnifying the area surrounded by the light emitter 1042. Advantageously, such a configuration reduces the perceptibility of non-light-emitting areas that might otherwise be perceived as dark spaces by the user. However, because the microlens 1302 effectively magnifies the associated light emitter 1044 such that it extends across the entire area of ​​the microlens 1304, non-light-emitting areas can be masked.

[0297] Continue to refer to Figure 30A The relative sizes of the light emitter 1044 and the collimator 1302 can be selected such that light from the light emitter 1042 fills the associated collimator 1301. For example, the light emitters 1044 can be spaced far enough such that the microlens collimator 1302 with the desired curvature can be formed to extend over a single light emitter in the light emitter 1041. Additionally, as described above, the size and shape of the coupling optical element 1022b are preferably selected such that the cross-sectional shape and size of the beam 1032b matches or exceeds that of the beam 1032b when it is incident on the coupling optical element. Thus, in some embodiments, the width 1025 of the coupling optical element 1022b is equal to or greater than the width of the microlens 1302. Preferably, the width 1025 is greater than the width of the microlens 1302 to account for some diffusion in the beam 1032b. As discussed herein, the width 1025 can also be selected to mitigate bounce and can be shorter than the length of the coupling optical element 1022b (which is orthogonal to the width). In some embodiments, the width 1025 may extend along the same axis as the propagation direction of the coupled light 1032b through the waveguide 1020b before being coupled out for propagation to the eye 210.

[0298] Now for reference Figure 30B An example of a light projection system 1010 is shown, comprising multiple nanowire LED microdisplays 1030a, 1030b, 1030c and associated light collimator arrays 1300a, 1300b, 1300c. The angular emission profile of the light emitted by the microdisplays 1030a, 1030b, 1030c is narrowed by the light collimator arrays 1300a, 1300b, 1300c, thereby facilitating the collection of a large percentage of the emitted light by the projection optics 1070 after the light propagates through the optical combiner 1050. The projection optics 1070 then guides the light to an eyepiece, such as eyepiece 1020 (e.g., ...). Figure 11A and 12 -14)(not shown).

[0299] Figure 30C An example of a wearable display system with multiple nanowire LED microdisplays 1030a, 1030b, and 1030c is shown, each nanowire LED microdisplay having an associated light collimator array 1300a, 1300b, and 1300c. The illustrated display system includes multiple microdisplays 1030a, 1030b, and 1030c for emitting light carrying image information. As shown, microdisplays 1030a, 1030b, and 1030c can be microLED panels. In some embodiments, the microdisplays can be monochrome microLED panels, each configured to emit a different component color. For example, microdisplay 1030a can be configured to emit red light 1032a, microdisplay 1030b can be configured to emit green light 1032b, and microdisplay 1030c can be configured to emit blue light 1032c.

[0300] Each microdisplay 1030a, 1030b, 1030c may have an associated optical collimator array 1300a, 1300b, 1300c, respectively. The optical collimators narrow the angular emission profile of the light 1032a, 1032b, 1032c from the light emitters of the associated microdisplays. In some embodiments, a single light emitter has a dedicated associated optical collimator (e.g., Figure 30A (As shown).

[0301] Continue to refer to Figure 30C Optical collimator arrays 1300a, 1300b, and 1300c are located between associated microdisplays 1030a, 1030b, and 1030c and an optical combiner 1050, which may be an X-cube. As shown, the optical combiner 1050 has internal reflective surfaces 1052 and 1054 for reflecting incident light beyond the output surface of the optical combiner. In addition to narrowing the angular emission profile of the incident light, the optical collimator arrays 1300a and 1300c can be configured to redirect light from the associated microdisplays 1030a and 1030c such that the light strikes the internal reflective surfaces 1052 and 1054 of the optical combiner 1050 at an angle suitable for propagation toward the associated optical coupling optics 1022a and 1022c. In some embodiments, in order to redirect light in a particular direction, the optical collimator arrays 1300a, 1300c may include microlenses or reflective traps, which, as disclosed herein, may be asymmetrical and / or the light emitter may be offset from the center relative to the microlens or reflective trap.

[0302] Continue to refer to Figure 30CA projection optics 1070 (e.g., a projection lens) is disposed at the output surface of the optical combiner 1050 to receive image light emitted from the optical combiner. The projection optics 1070 may include a lens configured to converge or focus the image light onto the eyepiece 1020. As shown, the eyepiece 1020 may include multiple waveguides, each configured to couple in and out light of a specific color. For example, waveguide 1020a may be configured to receive red light 1032a from the microdisplay 1030a, waveguide 1020b may be configured to receive green light 1032b from the microdisplay 1030b, and waveguide 1020c may be configured to receive blue light 1032c from the microdisplay 1030c. Each waveguide 1020a, 1020b, 1020c has associated light-coupled optical elements 1022a, 1022b, 1022c for coupling light therein. Furthermore, as discussed in this article, waveguides 1020a, 1020b, and 1020c can respectively correspond to Figure 9B Waveguides 670, 680, and 690, each with associated orthogonal pupil expanders (OPE) and exit pupil expanders (EPE), ultimately couple light 1032a, 1032b, and 1032c to the user.

[0303] As discussed herein, wearable display systems incorporating microdisplays are preferably configured to output light with varying wavefront divergence to provide comfortable accommodation-convergence matching for the user. These varying wavefront divergences can be achieved using coupling optics with different refractive powers. As discussed herein, the coupling optics can be located on or within the waveguide of the eyepiece (such as eyepiece 1020). Figure 11A and 12 -14). In some embodiments, the lens may be used to increase the wavefront divergence provided by the coupled optics, or may be used to provide the desired wavefront divergence in a configuration in which the coupled optics are configured to output collimated light.

[0304] Figure 31A and 31B An example of an eyepiece 1020 with a lens that alters the wavefront divergence of light directed to the viewer is shown. Figure 31A An eyepiece 1020 with a waveguide structure 1032 is shown. In some embodiments, as discussed herein, light of all component colors can be coupled into a single waveguide, such that the waveguide structure 1032 comprises only a single waveguide. This advantageously provides a compact eyepiece. In some other embodiments, the waveguide structure 1032 can be understood to comprise multiple waveguides (e.g., Figure 11A and 12Waveguides 1032a, 1032b, and 1032c (-13A) can be configured to relay light of a single component color to the user's eye.

[0305] In some embodiments, the zoom lens elements 1530 and 1540 can be disposed on either side of the waveguide structure 1032. The zoom lens elements 1530 and 1540 can be in the path of image light from the waveguide structure 1032 to the eye 210, and also in the path of light from the surrounding environment through the waveguide structure 1032 to the eye 210. The zoom optical element 1530 can modulate the wavefront divergence of the image light output from the waveguide structure 1032 to the eye 210. It will be understood that the zoom optical element 1530 can have a refractive power that may distort the world view of the eye 210. Therefore, in some embodiments, a second zoom optical element 1540 can be provided on the world side of the waveguide structure 1032. The second zoom optical element 1540 can provide a refractive power opposite to that of the zoom optical element 1530 (or, in the case that the waveguide structure 1032 has refractive power, opposite to the net refractive power of the optical element 1530 and the waveguide structure 1032), such that the net refractive power of the zoom lens elements 1530, 1540 and the waveguide structure 1032 is essentially zero.

[0306] Preferably, the refractive power of the variable focus lens elements 1530 and 1540 can be dynamically changed, for example, by applying an electrical signal to them. In some embodiments, the variable focus lens elements 1530 and 1540 may include transmissive optical elements, such as dynamic lenses (e.g., liquid crystal lenses, electroactive lenses, conventional refractive lenses with moving elements, mechanically deformable lenses, electrowetting lenses, elastic lenses, or various fluids with different refractive indices). By changing the shape, refractive index, or other properties of the variable focus lens elements, the wavefront of the incident light can be altered. In some embodiments, the variable focus lens elements 1530 and 1540 may include a liquid crystal layer sandwiched between two substrates. The substrates may include optically transmissive materials, such as glass, plastic, acrylic, etc.

[0307] In some embodiments, in addition to providing variable wavefront divergence for placing virtual content on different depth planes, or as an alternative, the zoom lens elements 1530, 1540 and waveguide structure 1032 can advantageously provide a net refractive power equal to the user's prescription refractive power for a corrective lens. Thus, the eyepiece 1020 can be used as an alternative to a lens for correcting refractive errors, including myopia, hyperopia, presbyopia, and astigmatism. Further details regarding the use of zoom lens elements as an alternative to corrective lenses can be found in U.S. Application No. 15 / 481,255, filed April 6, 2017, the entire disclosure of which is incorporated herein by reference.

[0308] Now for reference Figure 31B In some embodiments, eyepiece 1020 may include a static rather than a variable lens element. Figure 31B Similarly, waveguide structure 1032 may include a single waveguide (e.g., which can relay light of different colors) or multiple waveguides (e.g., each of which can relay light of a single component color). Likewise, waveguide structure 1034 may include a single waveguide (e.g., which can relay light of different colors) or multiple waveguides (e.g., each of which can relay light of a single component color). One or both of waveguide structures 1032 and 1034 may have refractive power and may output light with a specific wavefront divergence, or may simply output collimated light.

[0309] Continue to refer to Figure 31B In some embodiments, the eyepiece 1020 may include static lens elements 1532, 1534, and 1542. Each of these lens elements is positioned in the path of light entering the eye 210 from the surrounding environment through waveguide structures 1032 and 1034. Additionally, lens element 1532 is positioned between waveguide structure 1032 and the eye 210. Lens element 1532 modifies the wavefront divergence of the light output from waveguide structure 1032 to the eye 210.

[0310] Lens element 1534 modifies the wavefront divergence of light output from waveguide structure 1034 to eye 210. It will be understood that light from waveguide structure 1034 also passes through lens element 1532. Therefore, the wavefront divergence of light output from waveguide structure 1034 is modified by lens elements 1534 and 1532 (and waveguide structure 1032 in the case where waveguide structure 10032 has refractive power). In some embodiments, lens elements 1532, 1534, and waveguide structure 1032 provide a specific net refractive power for light output from waveguide structure 1034.

[0311] The illustrated embodiment provides two different levels of wavefront divergence, one for light output from waveguide structure 1032 and a second for light output from waveguide structure 1034. Therefore, a virtual object can be placed on two different depth planes, corresponding to different levels of wavefront divergence. In some embodiments, additional levels of wavefront divergence, and thus additional depth planes, can be provided by adding an additional waveguide structure between lens element 1532 and eye 210, and an additional lens element between the additional waveguide element and eye 210. Further levels of wavefront divergence can be similarly added by adding further waveguide structures and lens elements.

[0312] Continue to refer to Figure 31BIt will be understood that lens elements 1532, 1534 and waveguide structures 1032, 1034 provide net refractive power that may distort the user's view of the world. Therefore, lens element 1542 can be used to counteract the refractive power and distortion of ambient light. In some embodiments, the refractive power of lens element 1542 is set to counteract the total refractive power provided by lens elements 1532, 1534 and waveguide structures 1032, 1034. In some other embodiments, the net refractive power of lens element 1542; lens elements 1532, 1534; and waveguide structures 1032, 1034 is equal to the user's prescription refractive power for corrective lenses.

[0313] In some embodiments, and as Figure 32A and 32B As shown, even when using different microdisplays to generate light of different component colors, the optical combiner can be omitted from the projection system 1500. For example, microdisplays 1030a-1030c can each route light to the eyepiece 1020 via a dedicated associated projection optics in projection optics 1070a-1070c. As shown, microdisplay 1030a has an associated projection optics 1070a that focuses light onto an associated coupling optics 1022a, microdisplay 1030b has an associated projection optics 1070b that focuses light onto an associated coupling optics 1022b, and microdisplay 1030c has an associated projection optics 1070c that focuses light onto an associated coupling optics 1022c.

[0314] It will be understood that several exemplary benefits can be achieved in embodiments that do not use the optical combiner 1500. As an example, light collection can be improved because the microdisplays 1030a-1030c can be placed closer to the projection optics 1070a-1070c when the intermediate optical combiner 1500 is omitted. Therefore, higher light utilization efficiency and image brightness can be achieved. Additionally, optical aberrations (such as crosstalk) and inefficiencies (due to the requirement for a large acceptance angle and the inefficiency of reflected light) associated with light propagation through the X-cube can be advantageously avoided. As another example, the projection system 1500 can be simplified and customized for light of specific component colors. For example, the optical design for each corresponding projection optics 1070a-1070C can be individually calibrated for each component color of light generated by the microdisplays 1030a-1030c. In this way, the projection system 1500 can avoid the need for achromatic adjustments to the projection optics.

[0315] As another example of benefits, and such as Figure 32AAs shown, light from each of the projection optics 1070a-1070c can be advantageously focused more specifically onto the corresponding associated coupling optics 1022a-1022c. Figures 32A to 32B The example allows for more precise focusing of each component color onto the corresponding coupling elements 1022a-1022c. The projection optics 1070a-1070c for each component color can be configured to precisely focus light onto the corresponding coupling elements 1022a-1022c. In some embodiments, this precise focusing can improve image quality by providing a well-focused image for each component color.

[0316] Figure 32A An example of a light projection system 1500 without an optical combiner (e.g., the optical combiner 1050 described above) is shown. In the example shown, three microdisplays 1030a-1030c provide light (e.g., component color light) to corresponding projection optics 1070a-1070c. Light from each microdisplay 1030a-1030c can be routed through the projection optics 1070a-1070c and focused onto corresponding coupling elements 1022a-1022c included in an eyepiece 1020. It will be understood that each microdisplay 1030a-1030c can have a different structure, wherein each microdisplay includes an array of nanowire LEDs formed on different backplates.

[0317] Figure 32B Another example of a wearable display system with a light projection system without an optical combiner is shown. In some embodiments, microdisplays 1030a-1030c can be formed as a single integrated unit, for example, microdisplays 1030a-1030c are placed on a single backplane 1093. In some embodiments, the backplane 1093 can be a silicon backplane, which may include electrical components for the microdisplays 1030a-1030c, and may include various electronic devices, such as CMOS devices for controlling the nanowire LEDs of the microdisplays 1030a-1030c.

[0318] As discussed in this article, reference Figure 32A and 32BIt will be understood that, in some embodiments, the illustrated eyepiece 1020 may be formed by a single waveguide, rather than by three waveguides. In such embodiments, a single waveguide may support coupling in, propagation in, and output of multiple colors (e.g., two or three colors). The single waveguide may include each of the coupling optics 1022a, 1022b, 1022c at different locations aligned with the light output of the associated corresponding microdisplays 1030a, 1030b, 1030c. As discussed herein, in some embodiments, the single waveguide may be formed of a high-refractive-index material (e.g., silicon carbide) for optical transmission.

[0319] Various exemplary embodiments of the invention are described herein. These examples are referred to in a non-limiting sense. They are provided to illustrate a wider applicability of the invention. Various changes may be made to the described invention and equivalents may be substituted without departing from the spirit and scope of the invention.

[0320] For example, while advantageously used with AR displays that provide images across multiple depth planes, the virtual content disclosed herein can also be displayed by a system that provides images on a single depth plane. Additionally, the display system described herein can also be used as a virtual reality display in which light from the surrounding environment does not pass through the eyepiece.

[0321] As another example, it will also be understood that each of the illustrated eyepieces 1020 having multiple waveguides may also simply include only a single waveguide. In some embodiments, the single waveguide may be formed of a high refractive index material that transmits light, such as silicon carbide (SiC). The single waveguide may include a single coupling optics element to couple light, for example, multiple different component colors. In other embodiments, the single waveguide may include multiple spatially separated coupling optics elements, each of which may be configured to couple light of different component colors. In some other embodiments, at least one of the coupling optics elements may be configured to couple light of multiple different component colors.

[0322] Furthermore, numerous modifications can be made to adapt particular circumstances, materials, composition of substances, processes, process actions (one or more), or steps (one or more) to the purposes, spirit, or scope of the invention. Moreover, as will be understood by those skilled in the art, each individual variation described and illustrated herein has discrete components and features that can be readily separated from or combined with features of any of the other several embodiments without departing from the scope or spirit of this disclosure. All such modifications are intended to be within the scope of the claims associated with this disclosure.

[0323] This invention includes methods that can be performed using a subject device. The methods may include actions of providing such suitable devices. Such provision can be performed by a user. In other words, the "providing" action only requires the user to obtain, access, approach, locate, set, activate, power on, or otherwise perform actions to provide the necessary means in this method. The methods described herein can be performed in any logically possible order of events and in the order in which events are recorded.

[0324] The exemplary aspects of the invention, along with details regarding material selection and manufacturing, have been described above. Further details of the invention can be understood in conjunction with the patents and disclosures mentioned above, as well as those generally known or understood by those skilled in the art. Additional actions, as commonly or logically used, can also be applied to the method-based aspects of the invention.

[0325] Furthermore, although the invention has been described with reference to several examples that optionally include various features, the invention is not limited to the invention as described or indicated with respect to each variation thereof. Various changes may be made to the described invention and equivalents may be substituted (whether set forth herein or not included for some reason of brevity) without departing from the true spirit and scope of the invention. Additionally, where a range of values ​​is provided, it should be understood that every intermediate value between the upper and lower limits of the range, and any other claimed value or intermediate value within the claimed range, is covered in the invention.

[0326] Furthermore, it should be anticipated that any optional feature of the described variant of the invention may be set forth and claimed independently or in combination with any one or more of the features described herein. References to singular items include the possibility of multiple identical items. More specifically, as used herein and in the associated claims, unless otherwise specifically stated, the singular forms “a,” “an,” “the,” and “the” include plural indicators. In other words, the use of articles allows for “at least one” of the subject matter items described above and in the claims associated with this disclosure. It should also be noted that such claims may be drafted to exclude any optional elements. Thus, this statement is intended to serve as a prior basis for using specialized terms such as “merely,” “only,” or using the “negative” restriction in conjunction with the recitation of claim elements. Without using such specialized terms, the term “comprising” in the claims associated with this disclosure should allow for the inclusion of any additional elements—regardless of whether a given number of elements are enumerated in such a claim, or the addition of a feature may be considered as a transformation of the nature of the elements set forth in such a claim.

[0327] Therefore, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the widest scope consistent with the disclosure, principles and novel features disclosed herein.

Claims

1. A head-mounted display system, comprising: Headband; X-Cube Prism A plurality of monochromatic nanowire LED microdisplays supported by the frame, wherein each monochromatic nanowire LED microdisplay is configured to output image light having component colors and facing different sides of the X-cube prism, and wherein the X-cube prism is configured to receive image light of each component color from the monochromatic nanowire LED microdisplays and output image light of each component color from the output side of the X-cube prism in different directions; and An eyepiece supported by the frame, wherein the eyepiece is configured to receive the image light from each monochrome nanowire LED microdisplay and to direct the image light to the user's eyes when the frame is mounted on the user.

2. The head-mounted display system according to claim 1, wherein The eyepiece includes multiple coupled optical elements, and The output side of the X-cube prism faces the coupled optical element.

3. The head-mounted display system of claim 2, wherein, The reflective surface of the X-cube prism is configured to direct light from the monochrome nanowire LED microdisplay onto different areas of the eyepiece.

4. The head-mounted display system of claim 3, wherein, The plurality of coupled optical elements have a spatial arrangement that provides different optical paths from the X-cube prism to the coupled optical elements, wherein the spatial arrangement of the region corresponds to the spatial arrangement of the coupled optical elements.

5. The head-mounted display system of claim 1, wherein, The eyepiece includes a plurality of waveguides forming a waveguide stack, each waveguide in the waveguide stack comprising: A coupling optical element, configured to couple light from the monochromatic nanowire LED microdisplay into the waveguide; and A coupling optical element is configured to couple the coupled light out of the waveguide.

6. The head-mounted display system of claim 5, wherein, The waveguide stack includes multiple sets of waveguides, wherein each set of waveguides includes a dedicated waveguide for component colors.

7. The head-mounted display system of claim 1, further comprising: A variable focus lens element, wherein a waveguide including diffractive light-coupled-in and-coupled-out optical elements is located between a first variable focus lens element and a second variable focus lens element, wherein the first variable focus lens element is configured to modify the wavefront divergence of light output from the waveguide, and wherein the second variable focus lens element is configured to modify the wavefront divergence of light from the external world propagating through the second variable focus lens element.

8. The head-mounted display system of claim 1, further comprising: A color filter between two adjacent waveguides of the waveguide stack of the eyepiece, wherein, in the optical path extending from the X-cube prism, the first waveguide of the adjacent waveguides precedes the second waveguide of the adjacent waveguides, wherein the color filter is configured to selectively absorb light of a wavelength corresponding to the wavelength of light coupled by the coupling optics of the first waveguide of the adjacent waveguides.

9. The head-mounted display system according to claim 8, further comprising: The third waveguide in the optical path, following the second waveguide in the adjacent waveguides; as well as Other color filters are configured to selectively absorb light of a wavelength corresponding to the wavelength of light coupled to the coupled optical element of the second waveguide in the adjacent waveguide.

10. The head-mounted display system of claim 1, wherein, Each monochrome nanowire LED microdisplay comprises a spaced array of monochrome nanowire microLEDs on a common substrate backplane.

11. The head-mounted display system of claim 10, wherein, The eyepiece includes multiple waveguides. The waveguides are stacked together. Each waveguide includes a coupled optical element. The spatial arrangement of the coupled optical elements includes different coupled optical elements located at different intervals on different waveguides. The spatial arrangement of the monochromatic nanowire micro-LED array is matched with the spatial arrangement of the coupled optical element.

12. A head-mounted display system, comprising: A waveguide assembly that includes one or more waveguides; as well as An image projection system comprising an X-cube prism and multiple monochromatic nanowire LED microdisplays is disclosed, the image projection system being configured to project an image onto the waveguide assembly, wherein each monochromatic nanowire LED microdisplay is configured to output image light having component colors and facing different sides of the X-cube prism, and wherein the X-cube prism is configured to receive image light of each component color from the monochromatic nanowire LED microdisplays and output image light of each component color from the output side of the X-cube prism in different directions. Each waveguide in the waveguide assembly includes: A coupling optical element configured to couple light from the image projection system into the waveguide; and A coupling optical element is configured to couple the coupled light out of the waveguide. The waveguide component is configured to output coupled light with a variable wavefront divergence corresponding to multiple depth planes.

13. The head-mounted display system of claim 12, wherein, Each of the LEDs in the monochromatic nanowire LED microdisplay has an angular emission profile of less than 50°.

14. The head-mounted display system of claim 12, further comprising: Projection optics configured to converge light from the monochromatic nanowire LED microdisplay onto the coupling optics of the one or more waveguides.

15. The head-mounted display system of claim 12, wherein, The individual light emitters in the light emitter are configured to emit light of one of the multiple component colors. The waveguide assembly includes multiple sets of waveguides. Each set of waveguides includes a dedicated waveguide for each component color, and each set of waveguides includes a coupling optical element configured to output light with wavefront divergence corresponding to a common depth plane, wherein different sets of waveguides output light with different wavefront divergence amounts corresponding to different depth planes.

16. The head-mounted display system according to claim 12, further comprising: A variable focus lens element, wherein the waveguide assembly is located between a first variable focus lens element and a second variable focus lens element, wherein the first variable focus lens element is configured to modify the wavefront divergence of light output from the waveguide assembly, and wherein the second variable focus lens element is configured to modify the wavefront divergence of light from the external world to the second variable focus lens element.

17. The head-mounted display system according to claim 12, further comprising: At least some of the main surfaces of the waveguides have absorbing color filters, wherein the absorbing color filters on the main surfaces of the waveguides are configured to absorb light of wavelengths coupled into the corresponding waveguides, wherein the waveguides are arranged in a stacked manner.

18. The head-mounted display system according to claim 12, wherein, The waveguide assembly includes a stack of waveguides, wherein the coupled optical element is configured to couple light, wherein the coupled light propagates substantially in a propagation direction through an associated waveguide, wherein the coupled optical element occupies a region having a width parallel to the propagation direction and a length along an axis intersecting the propagation direction, wherein the length is greater than the width.

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