Single pupil RGB light source

Abstract

An embodiment of the present disclosure is a system and method for a display. In an embodiment, the display system includes a light source configured to emit a first light, a lens configured to receive the first light, and an image generator configured to receive the first light and emit a second light. The display system further includes a plurality of waveguides, at least two of the plurality of waveguides include an internal coupling grating configured to selectively couple the second light. In some embodiments, the light source can include a single-pupil light source having a reflector and a micro LED array disposed within the reflector.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 135,533, filed January 8, 2021, and Provisional Application No. 63 / 165,663, filed March 24, 2021, the contents of both of which are incorporated by reference in their entireties herein.

[0002] TECHNICAL FIELD This disclosure relates generally to systems and methods for displaying visual information, and more particularly to systems and methods for displaying visual information within a mixed reality environment. [Background technology]

[0003] Virtual environments are ubiquitous in computing environments, finding use in video games (where a virtual environment may represent a game world), maps (where a virtual environment may represent a terrain to be navigated), simulations (where a virtual environment may simulate a real environment), digital storytelling (where virtual characters may interact with one another within a virtual environment), and many other applications. Modern computer users are generally comfortable perceiving and interacting with virtual environments. However, a user's experience with a virtual environment may be limited by the technology for presenting the virtual environment. For example, traditional displays (e.g., 2D display screens) and audio systems (e.g., fixed speakers) may be incapable of realizing a virtual environment in a manner that creates a compelling, realistic, and immersive experience.

[0004] Virtual reality ("VR"), augmented reality ("AR"), mixed reality ("MR"), and related technologies (collectively, "XR") share the ability to present to a user of an XR system sensory information corresponding to a virtual environment represented by data in a computer system. This disclosure contemplates specificity among VR, AR, and MR systems (although some systems may be categorized as VR in one aspect (e.g., visual aspects) and simultaneously categorized as AR or MR in another aspect (e.g., audio aspects). As used herein, a VR system presents a virtual environment that replaces the user's real environment in at least one aspect, e.g., a VR system may present a user with a view of the virtual environment while simultaneously obscuring that view of the real environment, such as with a light-blocking head-mounted display. Similarly, a VR system may present a user with audio corresponding to the virtual environment while simultaneously blocking (attenuating) the audio from the real environment.

[0005] VR systems may suffer from various drawbacks resulting from replacing the user's real environment with a virtual environment. One drawback is motion sickness, which may occur when the user's field of view in the virtual environment no longer corresponds to the state of their inner ear, which detects their balance and orientation in the real (but not the virtual) environment. Similarly, users may suffer disorientation in the VR environment if their own body and limbs (the view on which the user relies to feel "grounded" in the real environment) are not directly visible. Another drawback is the computational burden (e.g., memory, processing power) imposed on VR systems that must present a full 3D virtual environment, especially in real-time applications that seek to immerse the user in the virtual environment. Similarly, such environments may need to reach a very high level of realism to be considered immersive, as users tend to be sensitive to even slight imperfections in the virtual environment, any of which may destroy the user's immersion in the virtual environment. Yet another disadvantage of VR systems is that such applications of the systems cannot take advantage of the wide range of sensory data in the real environment, such as the various sights and sounds experienced in the real world. A related disadvantage is that VR systems may struggle to create shared environments in which multiple users can interact, because users who share a physical space in the real environment may not be able to see or interact with each other directly in the virtual environment.

[0006] As used herein, an AR system presents a virtual environment that overlaps or overlays the real environment in at least one aspect. For example, an AR system may present a user with a view of the virtual environment that is overlaid on the user's view of the real environment, such as with a see-through head-mounted display that presents a displayed image while allowing light to pass through the display into the user's eyes. Similarly, an AR system may present a user with audio corresponding to the virtual environment while simultaneously mixing in audio from the real environment. Similarly, as used herein, an MR system may present a virtual environment that overlaps or overlays the real environment in at least one aspect, similar to an AR system, and additionally allow the virtual environment in the MR system to interact with the real environment in at least one aspect. For example, a virtual character in the virtual environment may flip a light switch in the real environment, causing a corresponding light bulb in the real environment to turn on or off. As another example, a virtual character may react to an audio signal in the real environment (such as with a facial expression). By maintaining the presentation of the real environment, AR and MR systems may avoid some of the aforementioned shortcomings of VR systems, e.g., motion sickness in the user is reduced because visual cues from the real environment (including the user's own body) may remain visible and such systems do not need to present the user with a fully realized 3D environment to be immersive. Additionally, AR and MR systems can create new applications that utilize and augment real-world sensory input (e.g., views and sounds of scenery, objects, and other users).

[0007] It can be difficult to present a virtual environment in a realistic manner to create an immersive experience for a user. For example, head mounted displays are designed to be lightweight and compact to minimize the burden on the user while presenting high quality images with a wide field of view ("FOV"). However, real-world design constraints can result in a trade-off between the size and weight of the optical system of the head wearable device and the quality of the image displayed. The quality of the image can be based, for example, on the efficiency of the optical system, e.g., without losing light, color uniformity, and field of view. Thus, there is a need for a compact optical system, such as for presenting a virtual environment in a VR, AR, or MR system, that is efficient and has a wide field of view. Summary of the Invention [Means for solving the problem]

[0008] Disclosed herein are systems and methods for displays, such as for head-wearable devices. An exemplary display system may include a light source configured to emit a first light, a lens configured to receive the first light, and an image generator configured to receive the first light and emit a second light. The display system may further include a plurality of waveguides, at least one of the plurality of waveguides may include an internal coupling grating configured to selectively couple the second light. In some embodiments, the light source may comprise a single-pupil light source having a reflector and a micro LED array disposed within the reflector. The embodiments disclosed herein may provide a compact and efficient display system. [Brief description of the drawings]

[0009] [Figure 1A] 1A-1C illustrate an example mixed reality environment in accordance with one or more embodiments of the present disclosure. [Figure 1B]1A-1C illustrate an example mixed reality environment in accordance with one or more embodiments of the present disclosure. [Figure 1C] 1A-1C illustrate an example mixed reality environment in accordance with one or more embodiments of the present disclosure.

[0010] [Figure 2A] 2A-2D illustrate components of an example mixed reality system that may be used to generate and interact with a mixed reality environment in accordance with one or more embodiments of the present disclosure. [Figure 2B] 2A-2D illustrate components of an example mixed reality system that may be used to generate and interact with a mixed reality environment in accordance with one or more embodiments of the present disclosure. [Figure 2C] 2A-2D illustrate components of an example mixed reality system that may be used to generate and interact with a mixed reality environment in accordance with one or more embodiments of the present disclosure. [Figure 2D] 2A-2D illustrate components of an example mixed reality system that may be used to generate and interact with a mixed reality environment in accordance with one or more embodiments of the present disclosure.

[0011] [Figure 3A] FIG. 3A illustrates an example mixed reality handheld controller that may be used to provide input to a mixed reality environment in accordance with one or more embodiments of the present disclosure.

[0012] [Figure 3B] FIG. 3B illustrates an example auxiliary unit that may be used with an example mixed reality system in accordance with one or more embodiments of the present disclosure.

[0013] [Figure 4] FIG. 4 illustrates an example functional block diagram of an example mixed reality system in accordance with one or more embodiments of the present disclosure.

[0014] [Diagram 5] FIG. 5 illustrates an example optical system for an example mixed reality system in accordance with one or more embodiments of the present disclosure.

[0015] [Figure 6] FIG. 6 illustrates an example optical system for an example mixed reality system in accordance with one or more embodiments of the present disclosure.

[0016] [Figure 7] FIG. 7 illustrates an example optical system for an example mixed reality system in accordance with one or more embodiments of the present disclosure.

[0017] [Figure 8A] 8A-8C illustrate an example optical system for an example mixed reality system in accordance with one or more embodiments of the present disclosure. [Figure 8B] 8A-8C illustrate an example optical system for an example mixed reality system in accordance with one or more embodiments of the present disclosure. [Figure 8C] 8A-8C illustrate an example optical system for an example mixed reality system in accordance with one or more embodiments of the present disclosure.

[0018] [Figure 9] FIG. 9 illustrates an example reflector for an example optical system in accordance with one or more embodiments of the present disclosure.

[0019] [Figure 10] FIG. 10 illustrates an example light source for an example optical system in accordance with one or more embodiments of the present disclosure.

[0020] [Figure 11A]11A-11B illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 11B] 11A-11B illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0021] [Figure 12A] 12A-12B illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 12B] 12A-12B illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0022] [Figure 13A] 13A-13B illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 13B] 13A-13B illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0023] [Figure 14A] 14A-14B illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 14B] 14A-14B illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0024] [Figure 15A]15A-15H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 15B] 15A-15H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 15C] 15A-15H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 15D] 15A-15H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 15E] 15A-15H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 15F] 15A-15H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 15G] 15A-15H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 15H] 15A-15H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0025] [Figure 16A] 16A-16H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 16B] 16A-16H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 16C] 16A-16H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 16D] 16A-16H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 16E] 16A-16H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 16F] 16A-16H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 16G] 16A-16H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 16H] 16A-16H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0026] [Figure 17A] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 17B] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 17C] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 17D] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 17E] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 17F] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 17G] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 17H] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 17I] 17A-17I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0027] [Figure 18A] 18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 18B] 18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 18C] 18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 18D] 18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 18E]18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 18F] 18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 18G] 18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 18H] 18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 18I] 18A-18I illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0028] [Figure 19A] 19A-19H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 19B] 19A-19H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 19C] 19A-19H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 19D] 19A-19H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 19E] 19A-19H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 19F] 19A-19H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 19G] 19A-19H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure. [Figure 19H] 19A-19H illustrate example illuminance of an example micro-LED array for an example optical system in accordance with one or more embodiments of the present disclosure.

[0029] [Figure 20] FIG. 20 illustrates an example micro LED array for an example optical system in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Detailed Description In the following description of the embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown, by way of illustration, specific embodiments which may be practiced. It is to be understood that other embodiments may be used and structural changes may be made without departing from the scope of the disclosed embodiments. Mixed Reality Environment

[0031] Like all people, users of a mixed reality system exist in a real environment, i.e., the three-dimensional portion of the "real world" and all of its contents are perceivable by the user. For example, the user perceives the real environment using his or her normal human senses, i.e., sight, hearing, touch, taste, and smell, and interacts with the real environment by moving his or her body within the real environment. Locations within the real environment can be described as coordinates in a coordinate space, e.g., the coordinates can comprise latitude, longitude, and altitude relative to sea level, distance in three orthogonal dimensions from a reference point, or other suitable values. Similarly, a vector can describe a quantity that has a direction and a magnitude in the coordinate space.

[0032] A computing device may maintain a representation of the virtual environment, for example, in a memory associated with the device. As used herein, a virtual environment is a computed representation of a three-dimensional space. A virtual environment may include a representation of any objects, actions, signals, parameters, coordinates, vectors, or other properties associated with that space. In some examples, a circuit (e.g., a processor) of a computing device may maintain and update the state of the virtual environment, i.e., the processor may determine the state of the virtual environment at a second time t1 based on data associated with the virtual environment and / or input provided by a user at a first time t0. For example, if an object in the virtual environment is located at a first coordinate at time t0 and has certain programmed physical parameters (e.g., mass, coefficient of friction), and input received from a user indicates that a force should be applied to the object in a certain directional vector, the processor may apply the laws of kinematics and use basic mechanics to determine the location of the object at time t1. The processor may use any suitable information known about the virtual environment and / or any suitable input to determine the state of the virtual environment at time t1. In maintaining and updating the state of the virtual environment, the processor may execute any suitable software, including software related to creating and deleting virtual objects in the virtual environment, software (e.g., scripts) for defining behavior of virtual objects or characters in the virtual environment, software for defining behavior of signals (e.g., audio signals) in the virtual environment, software for creating and updating parameters associated with the virtual environment, software for generating audio signals in the virtual environment, software for handling inputs and outputs, software for implementing network operations, software for applying asset data (e.g., animation data for moving a virtual object over time), or many other possibilities.

[0033] An output device, such as a display or speaker, can present any or all aspects of the virtual environment to the user. For example, the virtual environment can include virtual objects (which may include representations of inanimate objects, people, animals, lights, etc.) that can be presented to the user. The processor can determine a view of the virtual environment (e.g., corresponding to a "camera," with its origin coordinates, viewing axis, and frustum) and render on the display a viewable scene of the virtual environment corresponding to that view. Any suitable rendering technique may be used for this purpose. In some examples, the viewable scene may include only some virtual objects in the virtual environment and exclude certain other virtual objects. Similarly, the virtual environment may include audio aspects that can be presented to the user as one or more audio signals. For example, a virtual object in the virtual environment may generate a sound that originates from the object's location coordinates (e.g., a virtual character may speak or cause a sound effect), or the virtual environment may be associated with a musical cue or ambient sound that may or may not be associated with a particular location. The processor can determine audio signals corresponding to "listener" coordinates, e.g., audio signals corresponding to the synthesis of sounds in the virtual environment and that are mixed and processed to simulate the audio signals that would be heard by a listener at the listener coordinates, and present the audio signals to the user via one or more speakers.

[0034] Because the virtual environment exists only as a computational structure, the user cannot directly perceive the virtual environment using his or her normal senses. Instead, the user can only indirectly perceive the virtual environment, as presented to the user, for example, by a display, a speaker, a tactile output device, etc. Similarly, the user cannot directly touch, manipulate, or otherwise interact with the virtual environment, but can provide input data via input devices or sensors to a processor, which can use the device or sensor data to update the virtual environment. For example, a camera sensor can provide optical data indicating that the user is attempting to move an object in the virtual environment, and the processor can use that data to cause the object to respond appropriately in the virtual environment.

[0035] A mixed reality system can present a user with a mixed reality environment ("MRE") that combines aspects of real and virtual environments, for example, using a see-through display and / or one or more speakers (which may be incorporated, for example, into a wearable head device). In some embodiments, the one or more speakers may be external to the head-mounted wearable unit. As used herein, an MRE is a simultaneous representation of a real environment and a corresponding virtual environment. In some examples, the corresponding real and virtual environments share a single coordinate space, and in some examples, the real coordinate space and the corresponding virtual coordinate space are related to each other by a transformation matrix (or other suitable representation). Thus, a single coordinate (in some examples, together with the transformation matrix) can define a first location in the real environment and also a second corresponding location in the virtual environment, and vice versa.

[0036] In an MRE, a virtual object (e.g., in a virtual environment associated with the MRE) may correspond to a real object (e.g., in a real environment associated with the MRE). For example, if the real environment of the MRE comprises a real lamppost (real object) at some location coordinates, the virtual environment of the MRE may comprise a virtual lamppost (virtual object) at the corresponding location coordinates. As used herein, a real object in combination with its corresponding virtual object constitutes a "mixed reality object." It is not necessary for a virtual object to perfectly match or align with a corresponding real object. In some examples, a virtual object may be a simplified version of a corresponding real object. For example, if the real environment includes a real lamppost, the corresponding virtual object may comprise a cylindrical shape of approximately the same height and radius as the real lamppost (reflecting that a lamppost may be approximately cylindrical in shape). Simplifying virtual objects in this manner may enable computational efficiencies and simplify calculations to be performed on such virtual objects. Furthermore, in some examples of MRE, not all real objects in the real environment may be associated with a corresponding virtual object. Similarly, in some embodiments of the MRE, not all virtual objects in the virtual environment may be associated with corresponding real objects, i.e., some virtual objects may exist solely within the virtual environment of the MRE without any real-world counterpart.

[0037] In some embodiments, virtual objects may have characteristics that differ, sometimes significantly, from those of the corresponding real object. For example, the real environment in the MRE may comprise a green, two-pronged cactus, a thorny inanimate object, while the corresponding virtual object in the MRE may have the characteristics of a green, two-armed virtual character with human facial features and a surly attitude. In this embodiment, the virtual object resembles its corresponding real object in some characteristics (color, number of arms) but differs from the real object in other characteristics (facial features, personality). In this way, virtual objects have the potential to represent real objects in creative, abstract, exaggerated, or fictitious ways, or to impart behaviors (e.g., human personality) to otherwise inanimate real objects. In some embodiments, virtual objects may be purely fictitious creations with no real-world counterpart (e.g., virtual monsters in a virtual environment, perhaps in a location that corresponds to a void in the real environment).

[0038] Compared to a VR system that presents a virtual environment to a user while obscuring the real environment, a mixed reality system that presents an MRE offers the advantage that the real environment remains perceptible while the virtual environment is presented. Thus, a user of a mixed reality system can experience and interact with a corresponding virtual environment using visual and audio cues associated with the real environment. As an example, a user of a VR system may struggle to perceive or interact with a virtual object displayed in the virtual environment because the user cannot directly perceive or interact with it, as described above, whereas a user of an MR system may find it intuitive and natural to interact with a virtual object by seeing, hearing, and touching the corresponding real object in their own real environment. This level of interaction can enhance the user's sense of immersion, connection, and engagement with the virtual environment. Similarly, by presenting a real environment and a virtual environment simultaneously, a mixed reality system can reduce the negative psychological sensations (e.g., cognitive dissonance) and negative physical sensations (e.g., motion sickness) associated with a VR system. Mixed reality systems also offer many possibilities for applications that can augment or modify our experience of the real world.

[0039] 1A illustrates an exemplary real environment 100 in which a user 110 uses a mixed reality system 112. The mixed reality system 112 may comprise, for example, a display (e.g., a see-through display) and one or more speakers, and one or more sensors (e.g., a camera), as described below. The illustrated real environment 100 comprises a rectangular room 104A in which the user 110 is standing, and real objects 122A (lamp), 124A (table), 126A (sofa), and 128A (painting). The room 104A further comprises a location coordinate 106, which may be considered as the origin of the real environment 100. As shown in FIG. 1A, an environment / world coordinate system 108 (comprising an x-axis 108X, a y-axis 108Y, and a z-axis 108Z), with its origin at point 106 (world coordinates), may define a coordinate space for the real environment 100. In some embodiments, the origin 106 of the environment / world coordinate system 108 may correspond to where the mixed reality system 112 was powered on. In some embodiments, the origin 106 of the environment / world coordinate system 108 may be reset during operation. In some examples, the user 110 may be considered a real object in the real environment 100, and similarly, the body parts (e.g., hands, feet) of the user 110 may be considered real objects in the real environment 100. In some examples, the user / listener / head coordinate system 114 (comprising an x-axis 114X, a y-axis 114Y, and a z-axis 114Z) with its origin at point 115 (e.g., user / listener / head coordinate) may define a coordinate space for the user / listener / head on which the mixed reality system 112 is located. The origin 115 of the user / listener / head coordinate system 114 may be defined relative to one or more components of the mixed reality system 112. For example, the origin 115 of the user / listener / head coordinate system 114 may be defined relative to the display of the mixed reality system 112, such as during an initial calibration of the mixed reality system 112. Matrices (which may include translation matrices and quaternion or other rotation matrices) or other suitable representations can characterize the transformation between the user / listener / head coordinate system 114 space and the environment / world coordinate system 108 space.In some embodiments, the left ear coordinates 116 and right ear coordinates 117 may be defined relative to the origin 115 of the user / listener / head coordinate system 114. Matrices (which may include translation matrices and quaternion matrices or other rotation matrices) or other suitable representations can characterize the transformation between the left ear coordinates 116 and right ear coordinates 117 and the user / listener / head coordinate system 114 space. The user / listener / head coordinate system 114 can simplify the representation of location relative to the user's head or head-mounted device, e.g., relative to the environment / world coordinate system 108. Using simultaneous localization and mapping (SLAM), visual odometry, or other techniques, the transformation between the user coordinate system 114 and the environment coordinate system 108 can be determined and updated in real time.

[0040] 1B illustrates an exemplary virtual environment 130 that corresponds to the real environment 100. The shown virtual environment 130 comprises a virtual rectangular room 104B that corresponds to the real rectangular room 104A, a virtual object 122B that corresponds to the real object 122A, a virtual object 124B that corresponds to the real object 124A, and a virtual object 126B that corresponds to the real object 126A. Metadata associated with the virtual objects 122B, 124B, 126B may include information derived from the corresponding real objects 122A, 124A, and 126A. The virtual environment 130 additionally comprises a virtual monster 132, which does not correspond to any real object in the real environment 100. A real object 128A in the real environment 100 does not correspond to any virtual object in the virtual environment 130. A persistent coordinate system 133 (with x-axis 133X, y-axis 133Y, and z-axis 133Z) with its origin at point 134 (persistent coordinate) can define a coordinate space for the virtual content. The origin 134 of the persistent coordinate system 133 may be defined relative to / with respect to one or more real objects, such as real object 126A. A matrix (which may include a translation matrix and a quaternion matrix or other rotation matrix) or other suitable representation can characterize the transformation between the persistent coordinate system 133 space and the environment / world coordinate system 108 space. In some embodiments, virtual objects 122B, 124B, 126B, and 132 may each have their own persistent coordinate point relative to the origin 134 of the persistent coordinate system 133. In some embodiments, multiple persistent coordinate systems may exist, and virtual objects 122B, 124B, 126B, and 132 may each have their own persistent coordinate points relative to one or more persistent coordinate systems.

[0041] Persistent coordinate data may be coordinate data that persists with respect to the physical environment. Persistent coordinate data may be used by an MR system (e.g., MR system 112, 200) to place persistent virtual content, which may not be tied to the movement of a display on which a virtual object is displayed. For example, a two-dimensional screen may display only the virtual object for a certain position on the screen. As the two-dimensional screen moves, the virtual content may move with the screen. In some embodiments, persistent virtual content may be displayed in a corner of a room. When an MR user looks at the corner, they see the virtual content, they look away from the corner (the virtual content may no longer be visible because the virtual content may have moved from within the user's field of view to a location outside the user's field of view due to the movement of the user's head), and when they look back, the virtual content may be seen in the corner (similar to how a real object may behave).

[0042] In some embodiments, the persistent coordinate data (e.g., persistent coordinate system and / or persistent coordinate frame) may include an origin and three axes. For example, the persistent coordinate system may be assigned by the MR system to the center of the room. In some embodiments, the user may move around the room, exit and re-enter the room, etc., but the persistent coordinate system may remain in the center of the room (e.g., because it persists relative to the physical environment). In some embodiments, virtual objects may be displayed using transformations to the persistent coordinate data, which may enable persistent virtual content to be displayed. In some embodiments, the MR system may use simultaneous localization and mapping to generate the persistent coordinate data (e.g., the MR system may assign persistent coordinate systems to points in space). In some embodiments, the MR system may map the environment by generating persistent coordinate data at regular intervals (e.g., the MR system may assign persistent coordinate systems in a grid, where a persistent coordinate system may be within at least 5 feet of another persistent coordinate system).

[0043] In some embodiments, the persistent coordinate data may be generated by the MR system and transmitted to a remote server. In some embodiments, the remote server may be configured to receive the persistent coordinate data. In some embodiments, the remote server may be configured to synchronize persistent coordinate data from multiple observations. For example, multiple MR systems may map the same room with persistent coordinate data and transmit that data to a remote server. In some embodiments, the remote server may use this observation data to generate reference persistent coordinate data, which may be based on one or more observations. In some embodiments, the reference persistent coordinate data may be more accurate and / or reliable than a single observation of the persistent coordinate data. In some embodiments, the reference persistent coordinate data may be transmitted to one or more MR systems. For example, the MR system may use image recognition and / or location data to recognize that it is located in a room that has corresponding reference persistent coordinate data (e.g., because another MR system has previously mapped that room). In some embodiments, the MR system may receive reference persistent coordinate data corresponding to its location from the remote server.

[0044] 1A and 1B, the environment / world coordinate system 108 defines a shared coordinate space for both the real environment 100 and the virtual environment 130. In the illustrated embodiment, the coordinate space has its origin at point 106. Furthermore, the coordinate space is defined by the same three orthogonal axes (108X, 108Y, 108Z). Thus, a first location in the real environment 100 and a second corresponding location in the virtual environment 130 can be described with respect to the same coordinate space. This simplifies identifying and displaying corresponding locations in the real and virtual environments because the same coordinates can be used to identify both locations. However, in some embodiments, the corresponding real and virtual environments need not use a shared coordinate space. For example, in some embodiments (not shown), matrices (which may include translation matrices and quaternion matrices or other rotation matrices) or other suitable representations can characterize the transformation between the real environment coordinate space and the virtual environment coordinate space.

[0045] 1C illustrates an exemplary MRE 150 that simultaneously presents aspects of real environment 100 and virtual environment 130 to user 110 via mixed reality system 112. In the example shown, MRE 150 simultaneously presents to user 110 real objects 122A, 124A, 126A, and 128A from real environment 100 (e.g., via a transparent portion of a display of mixed reality system 112) and virtual objects 122B, 124B, 126B, and 132 from virtual environment 130 (e.g., via an active display portion of a display of mixed reality system 112). As described above, origin 106 acts as the origin for a coordinate space corresponding to MRE 150, and coordinate system 108 defines the x-, y-, and z-axes for the coordinate space.

[0046] In the illustrated example, the mixed reality objects comprise corresponding pairs of real and virtual objects (i.e., 122A / 122B, 124A / 124B, 126A / 126B) that occupy corresponding locations in coordinate space 108. In some examples, both real and virtual objects may be visible to user 110 at the same time. This may be desirable, for example, in cases where a virtual object presents information designed to augment the view of the corresponding real object (such as in a museum application where a virtual object presents a missing portion of an ancient damaged statue). In some examples, the virtual objects (122B, 124B, and / or 126B) may be displayed so as to occlude the corresponding real objects (122A, 124A, and / or 126A) (e.g., via active pixelated occlusion using a pixelated occlusion shutter). This may be desirable, for example, in cases where a virtual object acts as a visual substitute for a corresponding real object (such as in interactive storytelling applications, where inanimate real objects become "living" characters).

[0047] In some examples, real objects (e.g., 122A, 124A, 126A) may be associated with virtual content or helper data that may not necessarily constitute a virtual object. The virtual content or helper data may facilitate processing or handling of the virtual object within a mixed reality environment. For example, such virtual content may include a two-dimensional representation of the corresponding real object, a custom asset type associated with the corresponding real object, or statistical data associated with the corresponding real object. This information may enable or facilitate calculations involving the real object without incurring unnecessary computational overhead.

[0048] In some embodiments, the presentation described above may also incorporate audio aspects. For example, in MRE 150, virtual monster 132 may be associated with one or more audio signals, such as footstep effects, that are generated as the monster walks around MRE 150. As described further below, a processor in mixed reality system 112 may calculate an audio signal corresponding to a mixed and processed combination of all such sounds within MRE 150 and present the audio signal to user 110 via one or more speakers included within mixed reality system 112 and / or one or more external speakers. Exemplary Mixed Reality System

[0049] An exemplary mixed reality system 112 may include a wearable head device (e.g., a wearable augmented reality or mixed reality head device) that includes a display (which may include left and right see-through displays, which may be eyepiece displays, and associated components for coupling light from the displays to the user's eyes), left and right speakers (e.g., positioned adjacent the user's left and right ears, respectively), an inertial measurement unit (IMU) (e.g., mounted on a temple arm of the head device), a quadrature coil electromagnetic receiver (e.g., mounted on the left temple piece), left and right cameras (e.g., depth (time of flight) cameras) oriented away from the user, and left and right eye cameras (e.g., for detecting the user's eye movements) oriented toward the user. However, the mixed reality system 112 may incorporate any suitable display technology and any suitable sensors (e.g., optical, infrared, acoustic, LIDAR, EOG, GPS, magnetic). In addition, the mixed reality system 112 may incorporate networking features (e.g., Wi-Fi capabilities) to communicate with other devices and systems, including other mixed reality systems. The mixed reality system 112 may further include a battery (which may be mounted in an auxiliary unit, such as a belt pack designed to be worn around the waist of a user), a processor, and a memory. The wearable head device of the mixed reality system 112 may include a tracking component, such as an IMU or other suitable sensor, configured to output a set of coordinates of the wearable head device relative to the user's environment. In some examples, the tracking component may provide input to the processor to implement simultaneous localization and mapping (SLAM) and / or visual odometry algorithms. In some examples, the mixed reality system 112 may also include an auxiliary unit 320, which may be a handheld controller 300 and / or a wearable belt pack, as described further below.

[0050] 2A-2D illustrate components of an example mixed reality system 200 (which may correspond to the mixed reality system 112) that may be used to present an MRE (which may correspond to the MRE 150) or other virtual environment to a user. FIG. 2A illustrates a perspective view of a wearable head device 2102 included in the example mixed reality system 200. FIG. 2B illustrates a top view of the wearable head device 2102 mounted on a user's head 2202. FIG. 2C illustrates a front view of the wearable head device 2102. FIG. 2D illustrates an edge view of an example eyepiece 2110 of the wearable head device 2102. As shown in FIGS. 2A-2C, the example wearable head device 2102 includes an example left eyepiece (e.g., a left transparent waveguide set eyepiece) 2108 and an example right eyepiece (e.g., a right transparent waveguide set eyepiece) 2110. Each eyepiece 2108 and 2110 may include a transmissive element through which the real environment may be visible, and a display element for presenting a display (e.g., via image-wise modulated light) that is overlapped with the real environment. In some embodiments, such a display element may include a surface diffractive optical element for controlling the flow of image-wise modulated light. For example, the left eyepiece 2108 may include a left internal coupling grating set 2112, a left orthogonal pupil expansion (OPE) grating set 2120, and a left exit (output) pupil expansion (EPE) grating set 2122. As used herein, pupil may refer to the exit of light from an optical element, such as a grating set or reflector. Similarly, the right eyepiece 2110 may include a right internal coupling grating set 2118, a right OPE grating set 2114, and a right EPE grating set 2116. The image-wise modulated light can be transferred to the user's eyes via the internal coupling gratings 2112 and 2118, the OPEs 2114 and 2120, and the EPEs 2116 and 2122. Each internal coupling grating set 2112, 2118 can be configured to deflect light towards its corresponding OPE grating set 2120, 2114.Each OPE grating set 2120, 2114 can be designed to progressively deflect light downward toward its associated EPE 2122, 2116, thereby extending the exit pupil formed horizontally. Each EPE 2122, 2116 can be configured to progressively redirect at least a portion of the light received from its corresponding OPE grating set 2120, 2114 outward to a user eyebox location (not shown), defined behind the eyepieces 2108, 2110, extending the exit pupil formed in the eyebox vertically. Alternatively, instead of the internal coupling grating sets 2112 and 2118, the OPE grating sets 2114 and 2120, and the EPE grating sets 2116 and 2122, the eyepieces 2108 and 2110 can include gratings and / or other arrangements of refractive and reflective features to control the coupling of the image-wise modulated light into the user's eye.

[0051] In some examples, the wearable head device 2102 can include a left temple arm 2130 and a right temple arm 2132, with the left temple arm 2130 including a left speaker 2134 and the right temple arm 2132 including a right speaker 2136. A quadrature coil electromagnetic receiver 2138 can be located in the left temple assembly or another suitable location in the wearable head unit 2102. An inertial measurement unit (IMU) 2140 can be located in the right temple arm 2132 or another suitable location in the wearable head device 2102. The wearable head device 2102 can also include a left depth (e.g., time-of-flight) camera 2142 and a right depth camera 2144. The depth cameras 2142, 2144 can be preferably oriented in different directions so that both cover a wider field of view.

[0052] 2A-2D, a left source 2124 of image-wise modulated light can be optically coupled into the left eyepiece 2108 through a left internal coupling grating set 2112, and a right source 2126 of image-wise modulated light can be optically coupled into the right eyepiece 2110 through a right internal coupling grating set 2118. The sources 2124, 2126 of image-wise modulated light can include, for example, a fiber optic scanner, a projector including an electronic light modulator such as a digital light processing (DLP) chip or a liquid crystal on silicon (LCoS) modulator, or an emissive display such as a micro light emitting diode (μLED) or micro organic light emitting diode (μOLED) panel that is coupled into the internal coupling grating sets 2112, 2118 using one or more lenses per side. The input coupling grating sets 2112, 2118 can deflect light from image-wise modulated light sources 2124, 2126 to angles above the critical angle for total internal reflection (TIR) ​​for the eyepieces 2108, 2110. The OPE grating sets 2114, 2120 progressively deflect the propagating light downwards by TIR towards the EPE grating sets 2116, 2122. The EPE grating sets 2116, 2122 progressively couple the light towards the user's face, including the pupils of the user's eyes.

[0053] In some examples, as shown in FIG. 2D , the left eyepiece 2108 and the right eyepiece 2110 each include multiple waveguides 2402. For example, each eyepiece 2108, 2110 can include multiple individual waveguides, each dedicated to a separate color channel (e.g., red, blue, and green). In some examples, each eyepiece 2108, 2110 can include multiple sets of such waveguides, each set configured to impart a different wavefront curvature to the emitted light. The wavefront curvature may be convex with respect to the user's eye, for example, to present a virtual object located at a distance in front of the user (e.g., by a distance corresponding to the inverse of the wavefront curvature). In some examples, the EPE grating sets 2116, 2122 can include curved grating grooves to provide a convex wavefront curvature by modifying the Poynting vector of the light exiting across each EPE.

[0054] In some examples, stereoscopically accommodated left and right eye images can be presented to the user through per-image light modulators 2124, 2126 and eyepieces 2108, 2110 to create the perception that the displayed content is three-dimensional. The perceived realism of the presentation of three-dimensional virtual objects can be enhanced by selecting the waveguides (and thus the corresponding wavefront curvatures) such that the virtual objects are displayed at distances that approximate the distances shown by the stereoscopic left and right images. The technique can also reduce motion sickness suffered by some users, which can be caused by differences between the depth perception cues provided by the stereoscopic left and right eye images and the automatic accommodation (e.g., object distance-dependent focus) of the human eye.

[0055] FIG. 2D illustrates an edge view from the top of the right eyepiece 2110 of the exemplary wearable head device 2102. As shown in FIG. 2D, the plurality of waveguides 2402 can include a first subset 2404 of three waveguides and a second subset 2406 of three waveguides. The two subsets 2404, 2406 of waveguides can be distinguished by different EPE gratings that feature different grating line curvatures to impart different wavefront curvatures to the exiting light. Within each of the subsets 2404, 2406 of waveguides, each waveguide can be used to couple a different spectral channel (e.g., one of the red, green, and blue spectral channels) to the user's right eye 2206. (Although not shown in FIG. 2D, the structure of the left eyepiece 2108 is similar to that of the right eyepiece 2110.)

[0056] 3A illustrates an example handheld controller component 300 of a mixed reality system 200. In some examples, the handheld controller 300 includes a grip portion 346 and one or more buttons 350 disposed along a top surface 348. In some examples, the buttons 350 may be configured for use as an optical tracking target to track six degrees of freedom (6DOF) movement of the handheld controller 300, for example, in conjunction with a camera or other optical sensor (which may be mounted in a head unit (e.g., wearable head device 2102) of the mixed reality system 200). In some examples, the handheld controller 300 includes a tracking component (e.g., an IMU or other suitable sensor) for detecting a position or orientation, such as a position or orientation relative to the wearable head device 2102. In some examples, such a tracking component may be positioned in a handle of the handheld controller 300 and / or may be mechanically coupled to the handheld controller. The handheld controller 300 can be configured to provide one or more output signals corresponding to one or more of a button press state, or a position, orientation, and / or movement of the handheld controller 300 (e.g., via an IMU). Such output signals may be used as inputs to a processor of the mixed reality system 200. Such inputs may correspond to the position, orientation, and / or movement of the handheld controller (which in turn corresponds to the position, orientation, and / or movement of the user's hand holding the controller). Such inputs may also correspond to a user pressing a button 350.

[0057] 3B illustrates an example auxiliary unit 320 of the mixed reality system 200. The auxiliary unit 320 can include a battery for providing energy and operating the system 200, and can include a processor for executing programs and operating the system 200. As shown, the example auxiliary unit 320 includes a clip 2128, such as for attaching the auxiliary unit 320 to a user's belt. It will also be apparent that other form factors are suitable for the auxiliary unit 320, including form factors that do not involve mounting the unit on a user's belt. In some embodiments, the auxiliary unit 320 is coupled to the wearable head device 2102 through a multi-tube cable, which may include, for example, electrical wires and optical fibers. A wireless connection between the auxiliary unit 320 and the wearable head device 2102 can also be used.

[0058] In some examples, the mixed reality system 200 can include one or more microphones to detect sounds and provide corresponding signals to the mixed reality system. In some examples, the microphones may be attached to or integrated with the wearable head device 2102 and configured to detect the user's voice. In some examples, the microphones may be attached to or integrated with the handheld controller 300 and / or the auxiliary unit 320. Such microphones may be configured to detect environmental sounds, ambient noise, the user's or a third party's voice, or other sounds.

[0059] FIG. 4 illustrates an example functional block diagram that may correspond to an example mixed reality system, such as the mixed reality system 200 described above (which may correspond to the mixed reality system 112 with respect to FIG. 1). As shown in FIG. 4, the example handheld controller 400B (which may correspond to the handheld controller 300 ("totem")) includes a totem / wearable head device six degree of freedom (6DOF) totem subsystem 404A, and the example wearable head device 400A (which may correspond to the wearable head device 2102) includes a totem / wearable head device 6DOF subsystem 404B. In an example, the 6DOF totem subsystem 404A and the 6DOF subsystem 404B cooperate to determine six coordinates (e.g., offsets in three translational directions and rotations along three axes) of the handheld controller 400B relative to the wearable head device 400A. The six degrees of freedom may be expressed relative to the coordinate system of the wearable head device 400A. The three translational offsets may be represented as X, Y, and Z offsets in such a coordinate system, as a translation matrix, or as some other representation. The rotational degrees of freedom may be represented as a sequence of yaw, pitch, and roll rotations, as a rotation matrix, as a quaternion, or as some other representation. In some examples, the wearable head device 400A, one or more depth cameras 444 (and / or one or more non-depth cameras) included within the wearable head device 400A, and / or one or more optical targets (e.g., buttons 350 of handheld controller 400B as described above or dedicated optical targets included within handheld controller 400B) may be used for 6DOF tracking. In some examples, the handheld controller 400B may include a camera as described above, and the wearable head device 400A may include an optical target for optical tracking in conjunction with the camera.In some examples, the wearable head device 400A and the handheld controller 400B each include a set of three orthogonally oriented solenoids that are used to wirelessly transmit and receive three distinguishable signals. By measuring the relative magnitudes of the three distinguishable signals received at each of the coils used to receive, the 6DOF of the wearable head device 400A relative to the handheld controller 400B can be determined. Additionally, the 6DOF totem subsystem 404A can include an inertial measurement unit (IMU), which is useful for providing improved accuracy and / or more timely information regarding high speed movements of the handheld controller 400B.

[0060] In some embodiments, the wearable system 400 may include a microphone array 407, which may include one or more microphones arranged on the headgear device 400A. In some embodiments, the microphone array 407 may include four microphones. Two microphones may be located on the front of the headgear 400A, and two microphones may be located on the back of the headgear 400A (e.g., one on the left rear and one on the right rear). In some embodiments, the signals received by the microphone array 407 may be transmitted to the DSP 408. The DSP 408 may be configured to perform signal processing on the signals received from the microphone array 407. For example, the DSP 408 may be configured to perform noise reduction, acoustic echo cancellation, and / or beam forming on the signals received from the microphone array 407. The DSP 408 may be configured to transmit the signals to the processor 416.

[0061] In some examples, it may be necessary to transform coordinates from a local coordinate space (e.g., a coordinate space fixed relative to the wearable head device 400A) to an inertial coordinate space (e.g., a coordinate space fixed relative to the real environment), e.g., to compensate for movement of the wearable head device 400A relative to the coordinate system 108. For example, such a transformation may be necessary so that the display of the wearable head device 400A presents virtual objects in an expected position and orientation relative to the real environment (e.g., a virtual person sitting in a real chair facing forward, regardless of the position and orientation of the wearable head device), rather than in a fixed position and orientation on the display (e.g., at the same position in the bottom right corner of the display), preserving the illusion that the virtual objects exist in the real environment (and do not appear unnaturally positioned in the real environment, e.g., as the wearable head device 400A shifts and rotates). In some examples, a compensation transformation between coordinate spaces can be determined by processing imagery from the depth camera 444 using SLAM and / or visual odometry procedures to determine a transformation of the wearable head device 400A relative to the coordinate system 108. In the example shown in FIG. 4, the depth camera 444 can be coupled to the SLAM / visual odometry block 406 and provide imagery to the block 406. The SLAM / visual odometry block 406 implementation can include a processor configured to process this imagery and then determine a position and orientation of the user's head, which can be used to identify a transformation between the head coordinate space and another coordinate space (e.g., an inertial coordinate space). Similarly, in some examples, an additional source of information regarding the user's head pose and location is obtained from the IMU 409. Information from the IMU 409 can be integrated with information from the SLAM / visual odometry block 406 to provide improved accuracy and / or more timely information regarding fast adjustments of the user's head pose and position.

[0062] In some examples, the depth camera 444 can provide 3D imagery to a hand gesture tracker 411, which can be implemented within a processor of the wearable head device 400A. The hand gesture tracker 411 can identify the user's hand gestures, for example, by matching the 3D imagery received from the depth camera 444 to stored patterns representing hand gestures. Other suitable techniques for identifying the user's hand gestures will also be apparent.

[0063] In some embodiments, one or more processors 416 may be configured to receive data from the 6DOF headgear subsystem 404B, the IMU 409, the SLAM / visual odometry block 406, the depth camera 444, and / or the hand gesture tracker 411 of the wearable head device. The processor 416 may also send and receive control signals to the 6DOF totem system 404A. The processor 416 may be wirelessly coupled to the 6DOF totem system 404A, such as in embodiments in which the handheld controller 400B is not tethered. The processor 416 may further communicate with additional components, such as an audio / visual content memory 418, a graphical processing unit (GPU) 420, and / or a digital signal processor (DSP) audio spatializer 422. The DSP audio spatializer 422 may be coupled to a head-related transfer function (HRTF) memory 425. The GPU 420 may include a left channel output coupled to a left source of imagewise modulated light 424 and a right channel output coupled to a right source of imagewise modulated light 426. The GPU 420 may output stereoscopic image data to the imagewise modulated light sources 424, 426, for example, as described above with respect to FIGS. 2A-2D. The DSP audio spatializer 422 may output audio to the left speaker 412 and / or the right speaker 414. The DSP audio spatializer 422 may receive an input from the processor 419 indicating a direction vector from the user to a virtual sound source (e.g., which may be moved by the user via the handheld controller 320). Based on the direction vector, the DSP audio spatializer 422 may determine a corresponding HRTF (e.g., by accessing an HRTF or by interpolating multiple HRTFs). The DSP audio spatializer 422 may then apply the determined HRTF to an audio signal, such as an audio signal corresponding to a virtual sound generated by a virtual object.This can improve the believability and realism of virtual sounds by incorporating the user's relative position and orientation to the virtual sounds in the mixed reality environment, i.e., by presenting virtual sounds that match the user's expectations of what they would hear if the virtual sounds were real sounds in a real environment.

[0064] 4, one or more of the processor 416, GPU 420, DSP audio spatializer 422, HRTF memory 425, and audio / visual content memory 418 may be included in an auxiliary unit 400C (which may correspond to auxiliary unit 320 described above). The auxiliary unit 400C may include a battery 427 to power its components and / or provide power to the wearable head device 400A or handheld controller 400B. Including such components in an auxiliary unit, which may be mounted on the user's waist, can limit the size and weight of the wearable head device 400A, which in turn can reduce fatigue in the user's head and neck.

[0065] 4 presents elements corresponding to various components of an exemplary mixed reality system, various other suitable arrangements of these components will be apparent to those skilled in the art. For example, elements shown in FIG. 4 as being associated with the auxiliary unit 400C may instead be associated with the wearable head device 400A or the handheld controller 400B. Further, some mixed reality systems may omit the handheld controller 400B or the auxiliary unit 400C entirely. Such variations and modifications are to be understood as falling within the scope of the disclosed embodiments. Exemplary Optical Systems

[0066] A wearable head device of an example mixed reality system (e.g., mixed reality system 200) may include an optical system for presenting images to a user via a display. Figures 5-7 and 8A-8C illustrate examples of optical systems that may be used in a wearable head device (e.g., wearable head device 2102).

[0067] 5 illustrates an example optical system 500 that may be used in a wearable head device (e.g., wearable head device 2102). The optical system 500 may include a light source including multiple LEDs 501a-c and a prism 507, an image generator 505, an angled partially transmissive partially reflective surface 509, and a projector lens assembly 503. In some embodiments, the image generator may include a spatial light modulator such as LcoS (liquid crystal on silicon).

[0068] As illustrated in the figure, the plurality of LEDs 501a-c may include at least one of a red LED 501a, a green LED 501b, and a blue LED 501c. The plurality of LEDs may be arranged to project light into a prism 507. In some embodiments, the prism 507 may be an x-cube configured to combine light from each of the LEDs 501a-c and output light 530 to the image generator 505. The prism 507 may introduce some inefficiency if some of the light entering the prism may be lost, e.g., scattered. In addition, the x-cube has image artifacts typically associated with the intersection of various prisms. In some embodiments, the light 530 may pass through a partially transmissive partially reflective surface 509 before being received by the image generator 505. As shown in the figure, the light source, e.g., multiple LEDs 501a-c and prism 507, are positioned such that light 530 emitted by prism 507 is on-axis with respect to axis 535 (i.e., light 530 is aligned along axis 535) and coaxial with the image generator 505.

[0069] The image generator 505 may receive and reflect the light 530 to form an image light 533. The image light 533 output by the image generator 533 may be reflected by the partially transmissive partially reflective surface 509 towards the projector lens assembly 503. A portion of the light 530 and image light 533 passing through and / or reflected by the partially transmissive partially reflective surface 509 may be lost, e.g., scattered or transmitted away from the lens 503. An eyepiece of the head wearable device may be configured to receive and present the image light 533 to the user. In some embodiments, the field of view (FOV) of the optical system 500 may be 55 degrees. This 55 degree FOV of the system 500 may be based on the focal length of the lens assembly 503. As illustrated in FIG. 5, the width (and correspondingly, the focal length) of the lens assembly 503 may be limited by the size, e.g., footprint, of the image generator 505 and the light source 501. In some embodiments, the lens 503 may have a shorter focal length lens 503, which can increase the FOV. However, the available space, e.g., footprint, to reduce the focal length is limited by the prism or beam splitter. In practice, this may limit the achievable field of view to 55 degrees.

[0070] 6 illustrates an example optical system 600 that may be used in a wearable head device (e.g., wearable head device 2102). Optical system 600 may include a light source including an RGB LED array 601, an image generator 605, e.g., a spatial light modulator such as LCoS, an angled partially transmissive partially reflective surface 609, and a projector lens assembly 603. Optical system 600 may be more compact than optical system 500. For example, optical system 600 does not need to include a prism to combine light from the light sources, thereby saving physical space.

[0071] As illustrated in the figure, the light source 601 may include an RGB LED array that emits light 630 to the image generator 605. In some embodiments, the light 630 may pass through a partially transmissive partially reflective surface 609 before being received by the image generator 605. Some of the light 630 and image light 633 that passes through and / or is reflected by the partially transmissive partially reflective surface 609 may be lost, e.g., scattered. In an example, the light source 601 and the image generator 605 are located on the same axis (635) such that light from the light source 601 is delivered to the image generator 605 along this axis. The image light 633 output by the image generator 633 may be reflected by the partially transmissive partially reflective surface 609 towards the projector lens assembly 603. An eyepiece of the head wearable device may be configured to receive the image light 633 and present it to the user. In some embodiments, the field of view (FOV) of the optical system 600 may be up to, for example, 55 degrees.

[0072] 7 illustrates a top-down view of an example optical system 700 that may be used in a wearable head device (e.g., wearable head device 2102). As illustrated in this figure, optical system 700 may include, for example, a light source 701, a lens assembly 703, an image generator 705, e.g., a spatial light modulator such as LCoS, a color filter 719, and a number of waveguides 711. In some embodiments, optical system 700 may further include a polarizer positioned between light source 701 and the number of waveguides 711.

[0073] The multiple waveguides 711 may be arranged in parallel to form a waveguide stack 710. The waveguide stack 710 may be configured such that a first face 723 of the waveguide stack 710 is exposed to a real-world environment 725 and a second face 727 of the stack faces distal to the real-world environment 725, e.g., toward the eye 720 of a user wearing a wearable head device. The optical system 700 may also include a circular polarizer 717 and an optical element stack 707 (referred to herein as "MSP"), which may include a polarizer (e.g., a linear polarizer) between the first and second quarter-wave plates.

[0074] The light source 701 may include one or more LED sources 701a-c. In some embodiments, the LED sources may include LEDs disposed within a reflector, e.g., a CPC reflector. As illustrated in the figure, the light source 701 includes three separate LED sources 701a-c. The three LED sources may each correspond to a primary color, red, green, and blue. In some embodiments, the LED sources may each have an exit pupil or exit aperture of about 1 mm. The light source 701 may be disposed on a first surface 723 of the waveguide stack 710. The light source may be located near the temple region of the head wearable device (such as that shown in FIG. 2A). The light source 701 may be configured to direct light 730 through the waveguide stack 710 and toward the lens assembly 703 and the image generator 705. In comparison to the exemplary optical systems 500 and 600, the light source 701 and image generator 705 as shown are off-axis, eg, the axes of the light source 701 and image generator 705 are not aligned.

[0075] Light 730, generated by light source 701, for example by LED sources 701a-c, reaches image generator 705 by passing through multiple waveguides 711 and lens assembly 703. In some embodiments, optical system 700 can be arranged such that light from light source 701 is transmitted through multiple waveguides 711 but not transmitted through color filters 719 and / or polarizer 717. Light 730 can pass through color filters 719 and / or polarizer 717 after being reflected from image generator 705, as discussed in more detail below. Lens assembly 703 can be configured to direct light 730 to image generator 705. In some embodiments, MSP 707 may be located between lens assembly 703 and image generator 705. Thus, light 730 may pass through MSP 707 before entering image generator 705. The optical system 700 illustrated in FIG. 7 may have a relatively large FOV (e.g., compared to optical systems 500 and 600) because large optical elements such as prisms, beam splitters, and waveguides positioned between the lens and the image generator may be omitted.

[0076] The image generator 705 can reflect the incident light 730 and generate image light 733. In some embodiments, the image generator can be a spatial light modulator such as LCoS. In response to exiting the image generator 705, the image light 733 can pass through the MSP 707. In some embodiments, the MSP 807 can be tilted to minimize the effect of reflections in the system on the image presented to the user. The image light 733 can then enter the lens assembly 703 where it is directed towards the waveguide stack 710. In response to reaching the second face 727 of the waveguide stack 710, the image light 733 can pass through a circular polarizer 717 and / or a color filter 719. The circular polarizer 717 can polarize the image light 733, while the color filter can filter out wavelengths that do not correspond to the wavelengths of the light output by the light source 701. In some embodiments, the optical system 700 may not include a color filter 719, for example, the light 730 may be selectively incoupled into the waveguide stack via an incoupling grating.

[0077] The internal coupling gratings 715a-c can then receive the filtered light. Each internal coupling grating may be configured to diffract or internally couple light of a particular wavelength into a corresponding waveguide. In other words, each of the LED sources 701a-c may output light at a particular wavelength, and the corresponding color filter 719 and internal coupling grating 715 may be tuned to the same wavelength. For example, the color filter 719a may filter out wavelengths that do not correspond to the wavelengths output by the light source 701a, and the internal coupling grating 715a may be configured to diffract light that corresponds to the wavelengths output by the LED source 701a.

[0078] As shown in FIG. 7, the LED sources 701a-c of the optical system 700 are spatially separated. The LED sources 701a-c may be spatially separated in both horizontal and vertical directions. Similarly, the internal coupling gratings 715a-c may be spatially separated both horizontally and vertically. Thus, the light emitted from each of the LED sources may travel along different paths and reach the respective internal coupling gratings 715a-c. For example, the light emitted from the LED source 701a may be spatially separated (vertically and horizontally) from the light emitted from the LED source 701b. Also, the image light received at the internal coupling grating 715a, which corresponds to the light emitted from the LED source 701a, may be spatially separated (vertically and horizontally) from the light received by the internal coupling grating 715b, which corresponds to the light emitted from the LED source 701b. This spatial separation of the light sources and the internal coupling gratings may limit color crosstalk.

[0079] As illustrated in FIG. 7, optical system 700 can provide a relatively compact configuration, for example, compared to optical systems 500 and 600. As discussed above, in the illustrated embodiment, light source 701 and image generator 705 are located off-axis from each other, which allows lens assembly 703 to direct light both to and from image generator 705. Thus, the lens assembly can be adjusted to have a shorter focal length and therefore a wider field of view, and the image generator can be located on the rear surface of the lens assembly. This can reduce the overall depth of optical system 700, for example, compared to optical systems 500 and 600. Furthermore, the FOV of optical system 700 can be larger, for example, a 70-100 degree FOV. In addition, optical system 700 can be more efficient because less light is lost to various optical components, for example, prisms and partially transmissive partially reflective surfaces.

[0080] 8A-8C illustrate an example of an optical system 800 that may be used in a wearable head device (e.g., wearable head device 2102) according to an embodiment of the present disclosure. FIG. 8A shows a top-down view of the optical system 800 that may be used in a wearable head device according to an embodiment of the present disclosure. FIG. 8B shows a perspective view of a waveguide stack of the optical system 800 that may be used in a wearable head device according to an embodiment of the present disclosure. FIG. 8C shows another view of an optical system that may be used in a wearable head device according to an embodiment of the present disclosure. The optical system 800 may be used to output light and / or images, for example, to a user of a wearable head device. As would be understood by one of ordinary skill in the art, each of these views shows an optical system for a monocular. The system may be replicated or otherwise modified for both eyes.

[0081] 8A illustrates a top-down view of an optical system 800 that may be used in a wearable head device according to an embodiment of the present disclosure. The optical system 800 may include, for example, a light source 801, a lens assembly 803, an image generator 805, and a plurality of waveguides 811. The plurality of waveguides 811 may be arranged in parallel to form a waveguide stack 810. The waveguide stack 810 may be configured such that a first side 823 of the waveguide stack 810 is exposed to a real-world environment 825 and a second side 827 of the stack faces distal to the real-world environment 825, for example, toward the eye 820 of a user wearing the wearable head device. The optical system 800 may also include a circular polarizer 817 and an MSP 807. The circular polarizer may be located on a second side 824 of the waveguide stack 810. The MSP 807 may be located between the lens assembly 803 and the LCOS 805. In some embodiments, the optical system 800 may include a color filter (not shown). In some embodiments, the multiple waveguides 811 may be truncated such that the light 830 from the light source 801 does not pass through the waveguide 811 or passes through one or more, but not all, of the waveguides on its path to the image generator 805. This configuration may reduce light loss. In some embodiments, the light source may further include a polarizer between the exit pupil of the CPC reflector and the waveguide.

[0082] The optical system 800 may include a single light source 801. In some embodiments, the light source 801 may include a single CPC reflector with a spatial light modulator, e.g., a micro LED array, disposed inside. The micro LED array may be disposed across the bottom of the CPC reflector or inside the entrance pupil within the CPC reflector. In some embodiments, the reflector may have an exit pupil diameter of about 1-1.3 mm. The micro LED array may be an RGB micro LED array, including multiple red, green, and blue LEDs. The micro LED array may be configured to sequentially turn on and off all of the LEDs corresponding to a specific color. For example, the micro LEDs may be configured to simultaneously turn on and off all green LEDs, simultaneously turn on and off all red LEDs, and simultaneously turn on and off all blue LEDs in a pattern to form a sequential RGB light source. The CPC reflector may collect and shape the light from the micro LED source, which typically has a Lambertian or near-Lambertian angular distribution. In this manner, the CPC reflector may form an exit pupil size that is optimized for the optical system and the ICG. The CPC reflector may also provide light at an optimal angular range corresponding to the FOV of the system. Thus, the light source 801 may provide a uniform and efficient light source in a small, e.g., single source package. Additional description related to micro LED arrays is provided below. The light source may be positioned near the temple region of the head wearable display, such as that shown in FIG. 2A. In some embodiments, the light source may be positioned on other portions of the wearable display.

[0083] The waveguide stack 810 of the optical system 800 may include a plurality of waveguides 811 including an internal coupling grating 815 and an external coupling grating 813. With reference to FIG. 8B, in some embodiments, three or more of the waveguides 811a-c may include an internal coupling grating 815a-c and an external coupling grating 813a-c. In some embodiments, the waveguides 811a-c may each further include an orthogonal pupil expander ("OPE") 814a-c configured to propagate the light 833a-c across the waveguides 811a-c and toward the corresponding external coupling gratings 813a-c. As shown in the figure, the internal coupling gratings 815a-c may be vertically and horizontally spatially aligned, e.g., overlapping.

[0084] In some embodiments, each of the internal coupling gratings 815a-c can selectively diffract a particular wavelength of light 833a-c into the corresponding waveguide 811a-c. For example, each image light 833a-c may correspond to a different wavelength, e.g., light 833a may correspond to a red wavelength, light 833b may correspond to a green wavelength, and light 833c may correspond to a blue wavelength. Thus, the internal coupling grating 815a may be sensitive to the red wavelengths of light 833a, the internal coupling grating 815b may be sensitive to the green wavelengths of light 833b, and the internal coupling grating 815c may be sensitive to the blue wavelengths of light 833c. For example, light 833a may correspond to red light wavelengths, and the internal coupling grating 815a may be configured to selectively diffract light 833a corresponding to red light wavelengths. When the internal coupling grating 815a receives light 833b or 833c, the light may pass through the internal coupling grating 815a without being diffracted into the waveguide 811a. The described configuration is exemplary, and one skilled in the art will recognize that any of the internal coupling gratings may accommodate any suitable wavelength. The OPE 814 may propagate the internally coupled light 835 in the horizontal direction by total internal reflection (TIR) ​​to the external coupling grating 813, where the internally coupled light 835 may be directed out of the waveguide stack 810 and toward the user's eye 820. In addition to the selective color internal coupling grating, the waveguide 811 may be formed to absorb colors that are not desired in that particular waveguide to further limit color crosstalk.

[0085] 7, the internal coupling gratings 815 may be arranged to be spatially overlapping, e.g., aligned. In some cases, when the internal coupling gratings overlap, the size of the projector and the overall optical system can be reduced. Furthermore, a single pupil light source may enable simpler and less expensive alignment and testing equipment.

[0086] Optical system 800 may function in a manner similar to that described above with respect to optical system 700. With reference to FIG. 8C , light source 801 may be disposed on a first surface 823 of waveguide stack 810. Light source 801 may be configured to direct light 830 through waveguide stack 810 and toward lens assembly 803 and image generator 805. Light source 801 and image generator 805 may be configured to be off-axis, e.g., such that the axes of light source 801 and image generator 805 are not aligned. Light 830 passes through lens assembly 803 such that image generator 805 receives light 830 generated by light source 801. Lens assembly 803 can be configured to direct light 830 to image generator 805. In some embodiments, light generator 805 may be disposed on a rear surface of lens assembly 803. In some embodiments, MSP 807 may be located between lens assembly 803 and image generator 805. Thus, light 830 may pass through MSP 807 before entering image generator 805. In some embodiments, MSP 807 may be tilted to minimize the effect of reflections in the system on the image presented to the user.

[0087] The image generator 805 may reflect the incident light 830 and generate image light 833. In response to exiting the image generator 805, the image light 833 may pass through the MSP 807. The image light 833 may then enter the lens assembly 803, where the light 833 may be directed towards the waveguide stack 810. In response to reaching the second side 827 of the waveguide stack 810, the image light 833 may pass through a circular polarizer 817 before entering the second side 827 of the waveguide stack 810.

[0088] The image light 833 received by the waveguide stack 810 may be diffracted by one of the internal coupling gratings 815. For example, if the image light 833 corresponds to a wavelength of the color red, the image light 833 may be diffracted by the internal coupling grating 815, which is configured to diffract light corresponding to the same wavelength. The internally coupled light 835 may then propagate along the waveguide 811 via TIR. The internally coupled light 835 may exit the waveguide 811 via the external coupling grating 813 and be presented to the user's eye 820. In some embodiments, an OPE may be included within the waveguide stack 810, as described with respect to FIG. 8B.

[0089] As discussed above with respect to optical system 700, optical system 800 can provide a relatively compact configuration that provides a uniform image with high throughput, e.g., efficiency. For example, light source 801 as shown is off-axis from image generator 805, so lens assembly 803 can be used to direct light to image generator 805. As shown, image generator 805 can be located behind lens assembly 803, which reduces the overall depth of optical system 800, as compared to, e.g., optical systems 500 and 600. In addition, optical system 800 can be more efficient because less light is lost to various optical components, e.g., prisms and partially transmissive partially reflective surfaces. Furthermore, optical system 800 can be smaller than optical system 700 due to the reduced footprint of light source 801 and spatially aligned internal coupling grating 815.

[0090] FIG. 9 illustrates a reflector 950 according to an embodiment of the present disclosure. The reflector 950 may include a light input aperture 951, a light output aperture 959, and a side surface 953. As shown in the figure, the reflector 950 may have a profile corresponding to a compound parabolic concentrator (CPC). For example, the side surface 953 of the reflector 950 may correspond to the profile of a CPC reflector. In some embodiments, the light input aperture 951 and the light output aperture 959 may be circular, elliptical, or rectangular. The light input aperture may be configured to receive light (e.g., light rays 931, 932, 933) from a light emitter (not shown). The light may reflect from the side surface 953 of the reflector and exit the reflector 950 through the light output aperture 959. In this manner, the reflector 950 collects edge rays. The spatial uniformity of the output light may be designed such that the distribution of light across the image generator is optimal for image quality. It is desirable for the reflector to exhibit improved spatial uniformity. Thus, the CPC may be designed to control the illumination size and angular distribution of light while increasing the efficiency of the system.

[0091] 10 illustrates a light source 1001 according to an embodiment of the present disclosure. The light source 1001 may be a single-pupil RGB light source (which may correspond to the light source 801). As shown in this figure, the light source 1001 may include a reflector 1050 and a micro LED array 1040.

[0092] The reflector 1050 may have a CPC profile, such as that discussed with respect to reflector 950 of Figure 9. In some embodiments, the side 1053 may have an elliptical, hyperbolic, or bicone-shaped profile. The profile of the side 1053 may be configured to provide an angularly controlled light output at the exit of the reflector 1050.

[0093] In some embodiments, the micro LED array 1040 may be positioned across the light input aperture 1051. Although the micro LED array 1040 is illustrated with the micro LED array 1040 outside the reflector 1050, one skilled in the art will understand that the micro LED array may be positioned inside the reflector 1040 at the light input aperture 1051. As explained above, the light generated by the micro LED array 1040 may include light in three primary colors, namely, blue (B), green (G), and red (R). In other words, the micro LED array 1040 may be an RGB micro LED array including a plurality of red, green, and blue LEDs (not shown individually). The plurality of red, green, and blue LEDs may each be arranged to be uniformly distributed across the bottom opening of the reflector 1050. In some embodiments, if more refractive power of a particular wavelength is desired, the number of micro LEDs corresponding to the desired wavelength may be increased and / or the micro LEDs corresponding to the desired wavelength may be larger than the micro LEDs corresponding to other wavelengths.

[0094] A substantially uniform distribution of the LEDs across the light input aperture 1051 may reduce or mitigate the formation of hot spots in the light exiting the light source 1001. For example, three LEDs, i.e., a red LED, a blue LED, and a green LED, may be installed together in a reflector to achieve a single-pupil RGB light source. However, this configuration results in substantial non-uniformity, e.g., hot spots, in the light exiting the light output aperture 1059. These hot spots in the light exiting the light source 1001 may in turn provide non-uniform illumination across the LCOS, which results in localization of color in the image light. In a wearable head device, the hot spots may appear to the user as areas on the display that are oversaturated with a particular color. For example, the display as viewed by the user may have areas that are oversaturated with blue tones. As another example, if the display were to present a true white image to the user, a first region of the image may appear blue, a second region of the image may appear green, and a third region of the image may appear red. This localization of visible color on the display is undesirable and can detract from the user's XR experience. It may be desirable for the display to exhibit greater uniformity of light.

[0095] To improve the uniformity of the light, the light source may include a diffuser to increase the spread, e.g., etendue, of the light exiting the light source. However, the diffuser may cause inefficiencies by scattering the light from the light source and reducing the maximum brightness of the display. Due to the substantially uniform distribution of the multiple micro LEDs, the light source 1001 may provide a uniform light output without an inefficient diffuser. In this manner, the light source 1001 may provide a small, e.g., single-pupil package that is both uniform and efficient. For example, in comparison to the systems 700 and 800 described above, one skilled in the art will appreciate that the three-pupil optical system 700 is likely to be larger than the single-pupil optical system 800. Furthermore, as discussed above, including RGB LED emitters in a single reflector results in a relatively large, inefficient reflector that provides non-uniform light. In comparison, the optical system 800 may provide an efficient and uniform light source in a small single-pupil package that does not need to rely on diffusers or other techniques that may result in light loss. Exemplary Micro LED Array

[0096] A light source, e.g., light source 801 or 1001, may include a micro LED array. A micro LED array may include multiple micro LEDs arranged in a panel. Each micro LED may form a pixel of the micro LED array. A micro LED array may have a number of different configurations. For example, when designing a micro LED array, the size and shape of each micro LED and the pattern or configuration of the micro LEDs within the array may be varied. For example, the micro LEDs may have a circular, rectangular, hexagonal, or radial shape, or any other suitable shape. Additionally, the micro LEDs may be arranged in a variety of configurations, including linear, rectilinear, or hexagonal arrays.

[0097] As discussed above, the micro LED array may be disposed within a reflector, e.g., a CPC reflector, to form a light source, e.g., light source 801 or 1001. The shape of the micro LEDs and the relative configuration of the micro LEDs may affect the illuminance of the light, e.g., light 830, that exits the light source. This in turn may affect the illuminance of the light received at the image generator 805, and ultimately, the light presented to the user. The light that exits the light source may correspond to light, e.g., light 830, that enters the optical system, e.g., optical system 800, through a single pupil of the light source, e.g., light source 801. As discussed above, this light may be reflected by the image generator, e.g., image generator 805, to form the image light to be presented to the user. Thus, changing the size, shape, and configuration of the micro LEDs affects the illuminance of the light that exits the pupil of the light source, e.g., light source 801, and thus the light presented to the user. The individual micro LED emitters can have the same size or can vary in size. The size of the individual micro LED emitters can range from 1 μm to 100 μm. The number of micro LED emitters can be determined by the size of the entrance pupil of the CPC reflector. The entrance pupil size can be related to the exit pupil of the CPC reflector. In some embodiments, the exit pupil size of the CPC reflector can be based on the size and configuration of the optical system, for example, the exit pupil size can be selected to optimize efficiency and modulation transfer function (MTF). In some embodiments, the fill factor of the array can be as high as possible to maximize the achievable optical power output.

[0098] 11A-18I illustrate examples of various configurations of micro LED arrays according to embodiments of the present disclosure. Embodiments of the present disclosure are not limited to the micro LED array configurations disclosed herein, rather, these examples are merely illustrative of types of micro LED array configurations according to embodiments of the present disclosure.

[0099] FIG. 11A illustrates a layout of a micro LED array 1100 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 1100 may be rectangular in shape and the micro LED sources may be rectangular in shape with a height and width of about 30 μm. While this figure illustrates micro LEDs of a single color, one skilled in the art will understand that the micro LED array may include additional micro LED sources corresponding to at least two additional colors. FIG. 11B illustrates the resulting illuminance of image light traversing, e.g., reflected by, an image generator based on a configuration of the optical system 800 including the micro LED array 1100.

[0100] FIG. 12A illustrates a layout of a micro LED array 1200 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 1200 may be rectangular in shape, and the micro LEDs may be rectangular in shape with a width of about 50 μm. While this figure illustrates micro LEDs of a single color, one skilled in the art will understand that the micro LED array may include additional micro LED sources corresponding to at least two additional colors. FIG. 12B illustrates the resulting illuminance of image light traversing, e.g., reflected by, an image generator based on a configuration of the optical system 800 including the micro LED array 1200.

[0101] FIG. 13A illustrates a layout of a micro LED array 1300 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 1300 may be rectangular in shape, and the micro LEDs may be rectangular in shape with a width and height of about 40 μm. While this figure illustrates a single color micro LED source, one skilled in the art will understand that the micro LED array may include additional micro LED sources corresponding to at least two additional colors. FIG. 13B illustrates the resulting illuminance of image light traversing, e.g., reflected by, an image generator based on a configuration of the optical system 800 including the micro LED array 1300.

[0102] FIG. 14A illustrates a layout of a micro LED array 1400 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 1400 may be hexagonal in shape and the micro LEDs may be rectangular in shape with a width of about 30 μm and a height of about 26 μm, although other sizes, e.g., 25-50 μm, may be used. While this figure illustrates a single color micro LED source, one skilled in the art will understand that the micro LED array may include additional micro LED sources corresponding to at least two additional colors. FIG. 14B illustrates the resulting illuminance of image light traversing, e.g., reflected by, an image generator based on a configuration of an optical system 800 including the micro LED array 1400.

[0103] FIG. 15A illustrates a layout of a micro LED array 1500 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 1500 may have a radial configuration and the micro LEDs may be rectangular in shape with a width and height of about 40 μm, although other sizes, e.g., 25-50 μm, may be used. This figure illustrates a configuration of micro LED sources including three colors. FIG. 15B illustrates the resulting illuminance of image light traversing, e.g., reflected by, an image generator based on a configuration of an optical system 800 including the micro LED array 1500. FIG. 15C illustrates a layout of the micro LED array 1500 for a first color of three colors. The figure illustrates the illuminance of light exiting a light source, e.g., an exit pupil of a reflector, for all of the micro LED sources corresponding to the first color emitting simultaneously. (It should be understood that the initial emission power and / or illuminance of each of the micro LED sources may be the same unless otherwise stated.) FIG. 15D illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 15C. FIG. 15E illustrates the illuminance of light exiting the pupil of a reflector with a micro LED array 1500 for a second color of three colors, for example, with a micro LED source corresponding to the second color emitting simultaneously. FIG. 15F illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 15E. FIG. 15G illustrates the illuminance of light exiting the pupil of a reflector with a micro LED array 1500 for a third color of three colors, for example, with a micro LED source corresponding to the third color emitting simultaneously. FIG. 15H illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 15G.

[0104] FIG. 16A illustrates a layout of a micro LED array 1600 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 1600 may have a hexagonal configuration, and the micro LEDs may be rectangular in shape with widths and heights of 25-50 μm. The micro LED array 1600 may include micro LED sources corresponding to the primary colors red, green, and blue. The figure illustrates the illuminance of all micro LED sources in the array 1600, e.g., corresponding to all three colors, measured at the exit pupil of a light source, e.g., a reflector. FIG. 16B illustrates the illuminance of image light reflected by an image generator of an optical system with the micro LED array 1600. FIG. 16C illustrates the layout of the micro LED array 1600 for a first of three colors. The figure illustrates the illuminance of the light of the micro LED array. (It should be understood that the initial emission power and / or illuminance of each of the micro LED sources may be the same unless otherwise stated.) FIG. 16D illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 16C. FIG. 16E illustrates the illuminance of light exiting the pupil of a reflector with a micro LED array 1600 for a second color of three colors, for example, with a micro LED source corresponding to the second color emitting simultaneously. FIG. 16F illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 16E. FIG. 16G illustrates the illuminance of light exiting the pupil of a reflector with a micro LED array 1600 for a third color of three colors, for example, with a micro LED source corresponding to the third color emitting simultaneously. FIG. 16H illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 16G.

[0105] FIG. 17A illustrates a layout of a micro LED array 1700 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 1700 may have a hexagonal configuration, and the micro LEDs may be circular in shape with a diameter of 25-50 μm. The micro LED array 1700 may include micro LED sources corresponding to the primary colors red, green, and blue. This figure illustrates the illuminance of all micro LED sources in the array 1700, for example, corresponding to all three colors. In some embodiments, all micro LEDs in the array may include micro LEDs corresponding to three colors, for example, red, green, and blue. FIG. 17B illustrates the illuminance of image light reflected by an image generator of an optical system with the micro LED array 1700. FIG. 17C illustrates the output of a true color detector that receives the output of the image generator when all of the micro LED sources of the micro LED array 1700 are emitting. FIG. 17D illustrates the layout of the micro LED array 1500 for a first of three colors. The figures illustrate the illuminance of light exiting a light source, e.g., an exit pupil of a reflector, for all of the micro LED sources corresponding to a first color emitting simultaneously. (Unless otherwise stated, it should be understood that the initial emission power and / or illuminance of each of the micro LED sources may be the same.) FIG. 17E illustrates the illuminance of image light reflected by an image generator of an optical system with a single color as shown in FIG. 17D. FIG. 17F illustrates the illuminance of light exiting a pupil of a reflector with a micro LED array 1700 for a second color of three colors, e.g., with a micro LED source corresponding to the second color emitting simultaneously. FIG. 17G illustrates the illuminance of image light reflected by an image generator of an optical system with a single color as shown in FIG. 17F. FIG. 17H illustrates the illuminance of light exiting a pupil of a reflector with a micro LED array 1700 for a third color of three colors, e.g., with a micro LED source corresponding to the third color emitting simultaneously. FIG. 17I illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 17H.

[0106] FIG. 18A illustrates a layout of a micro LED array 1800 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 1800 may have a hexagonal configuration, and the micro LEDs may be rectangular in shape with a width of 25-50 μm. The micro LED array 1800 may include micro LEDs corresponding to the primary colors red, green, and blue. The figure illustrates the illuminance of all of the micro LEDs in the array 1800, e.g., corresponding to all three colors, measured at the exit pupil of a light source, e.g., a reflector. FIG. 18B illustrates the illuminance of image light reflected by an image generator of an optical system with the micro LED array 1800. FIG. 18D illustrates the layout of the micro LED array 1800 for a first color of three colors. The figure illustrates the illuminance of light leaving a light source, e.g., an exit pupil of a reflector, for all of the micro LED sources corresponding to the first color emitting simultaneously. (It should be understood that the initial emission power and / or illuminance of each of the micro LED sources may be the same unless otherwise stated.) FIG. 18D illustrates a layout of a micro LED array 1500 for a first color of three colors. The figure illustrates the illuminance of light exiting a light source, e.g., an exit pupil of a reflector, for all of the micro LED sources corresponding to the first color. (It should be understood that the initial emission power and / or illuminance of each of the micro LED sources may be the same unless otherwise stated.) FIG. 18E illustrates the illuminance of image light reflected by an image generator of an optical system with a single color shown in FIG. 18D. FIG. 18F illustrates the illuminance of light exiting a pupil of a reflector with a micro LED array 1800 for a second color of three colors, e.g., with the micro LED sources corresponding to the second color emitting simultaneously. FIG. 18G illustrates the illuminance of image light reflected by an image generator of an optical system with a single color shown in FIG. 18F. Fig. 18H illustrates the illuminance of light exiting the pupil of a reflector with a micro LED array 1800 for a third of three colors, for example, where a micro LED source corresponding to the third color is emitting simultaneously. Fig. 18I illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in Fig. 18H.

[0107] In some embodiments, the micro LED array may use dithering to reduce the appearance of quantized patterns in the output of the light source exit pupil and increase the visual uniformity of the output across the image generator. FIGS. 19A-19H illustrate an example micro LED array including a slight dither of the micro LED elements from their center position. FIG. 19A illustrates the illuminance of all the micro LEDs contained within the array measured at the exit pupil of the light source, e.g., the exit aperture of a reflector. In some embodiments, the micro LED elements may have a dither of ±5 μm. FIG. 19A illustrates dithering, e.g., compared to FIG. 17D, the spacing of the micro LED elements appears irregular. FIG. 19B illustrates the illuminance of the image light reflected by the image generator of an optical system with a micro LED array 1900. FIG. 19C illustrates the illuminance of the light exiting the pupil of a reflector with a micro LED array 1900 for a single color, e.g., three colors, with the micro LED sources corresponding to the single color emitting simultaneously. FIG. 19D illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 19C. FIG. 19E illustrates a dithering configuration in which each column of a micro LED array is offset by a different amount, and elements within the same column can be offset by the same amount. For example, the column offset can be either 7 μm, 14 μm, or 21 μm. FIG. 19F illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 19E. FIG. 19G illustrates a dithering configuration in which four offset values ​​are repeated. As shown in the figure, the offset can include a set of four columns with offsets of -14 μm, -5 μm, 4 μm, and 13 μm, where this offset configuration can be repeated. FIG. 19H illustrates the illuminance of image light reflected by the image generator of the optical system with a single color shown in FIG. 19G.

[0108] FIG. 20 illustrates a layout of a micro LED array 2000 according to an embodiment of the present disclosure. As shown in this figure, the micro LED array 2000 may have a stripe configuration such that each micro LED comprises multiple stripes that extend across the micro LED array from end to end. For example, the micro LED array may include multiple vertical stripes, where the length of the stripes can vary based on the location of the stripes along the x-axis of the micro LED array. In some embodiments, the stripes may be rectangular in shape with a width of about 10-40 μm. The spacing between the stripes may be about 10 μm or less. In some embodiments, the micro LED array may have a diameter of about 0.7-1.00 mm. In some embodiments, the stripes may be arranged horizontally in columns such that the length of the stripes can vary based on the location of the stripes along the y-axis.

[0109] The micro LED array 2000 may include micro LED sources corresponding to the primary colors red, green, and blue. This figure illustrates an arrangement of all micro LED sources in the array 2000, for example, corresponding to all three colors. In some embodiments, all micro LEDs in the array may include micro LED sources corresponding to three colors, for example, red, green, and blue. In some embodiments, the three colors may be arranged in a repeating set, for example, repeating red-green-blue, repeating blue-red-green, etc. In some embodiments, the widths of the stripes corresponding to different colors may vary. For example, the stripes corresponding to red may have a first width, the stripes corresponding to green may have a second width, and the stripes corresponding to blue may have a third width, where the first, second, and third widths are different. The relative widths of the stripes corresponding to different colors (e.g., wavelengths) may be based on the desired refractive power of the particular color. In some embodiments, the width of the stripes may vary based on their relative location within the micro LED array, for example, narrower stripes located near the center of the micro LED array and wider stripes located near the edges.

[0110] 10, in some embodiments, the micro LED array 1040 may be located within the bottom of the reflector 1050 across the light input aperture 1051. In other embodiments, the micro LED array may be displaced from the bottom of the reflector, e.g., the micro LEDs may be located at different positions along the longitudinal axis of the reflector, the longitudinal axis corresponding to an axis perpendicular to the light input and output apertures of the reflector. In some examples, moving the micro LED array in the z direction may affect the focus and efficiency of the light output outlet, e.g., the exit pupil of the reflector.

[0111] Although the disclosed embodiments have been fully described with reference to the accompanying drawings, it should be noted that various changes and modifications will be apparent to those skilled in the art. For example, elements of one or more implementations may be combined, deleted, modified, or supplemented to form further implementations. Such changes and modifications are to be understood as being included within the scope of the disclosed embodiments as defined by the appended claims.

Claims

1. 1. A display system comprising: a light source configured to emit a first light; a lens configured to receive the first light; an image generator configured to receive the first light and emit a second light; a plurality of waveguides, at least two of the plurality of waveguides each including a respective internal coupling grating configured to selectively couple the second light; Equipped with the light source comprises a single pupil light source comprising a reflector and a micro LED array disposed within the reflector; the micro LED array comprises a plurality of stripes; The plurality of stripes include: a first stripe configured to emit light having a first wavelength, the first stripe being positioned and sized according to the first wavelength; a second stripe configured to emit light having a second wavelength, the second stripe positioned and sized according to the second wavelength; a third stripe configured to emit light having a third wavelength, the third stripe being positioned and sized according to the third wavelength; and Equipped with The first light has the first wavelength, the second wavelength, or the third wavelength.

2. 10. The display system of claim 1 , wherein the micro LED array includes at least a first plurality of micro LED sources configured to emit at the first wavelength and a second plurality of micro LED sources configured to emit at the second wavelength.

3. 10. The display system of claim 1 , wherein at least a first internal coupling grating is configured to internally couple light corresponding to the first wavelength and a second internal coupling grating is configured to internally couple light corresponding to the second wavelength.

4. 10. The display system of claim 1, wherein the light source is configured to emit the first wavelength at a first time and the second wavelength at a second time, the second time being different from the first time.

5. The display system of claim 1, wherein the internal coupling gratings of at least two of the plurality of waveguides are matched.

6. The display system of claim 1 , wherein the light source is offset from the image generator.

7. 10. The display system of claim 1, wherein the reflector comprises a compound parabolic concentrator reflector.

8. A head-wearable device, the head-wearable device comprising a display system, The display system comprises: a light source configured to emit a first light; a lens configured to receive the first light; an image generator configured to receive the first light and emit a second light; a plurality of waveguides, at least two of the plurality of waveguides each including a respective internal coupling grating configured to selectively couple the second light; Equipped with the light source comprises a single pupil light source comprising a reflector and a micro LED array disposed within the reflector; the micro LED array comprises a plurality of stripes; The plurality of stripes include: a first stripe configured to emit light having a first wavelength, the first stripe being positioned and sized according to the first wavelength; a second stripe configured to emit light having a second wavelength, the second stripe positioned and sized according to the second wavelength; a third stripe configured to emit light having a third wavelength, the third stripe being positioned and sized according to the third wavelength; and Equipped with A head-wearable device, wherein the first light has the first wavelength, the second wavelength, or the third wavelength.

9. 9. The head wearable device of claim 8, wherein the micro LED array includes at least a first plurality of micro LED sources configured to emit at the first wavelength and a second plurality of micro LED sources configured to emit at the second wavelength.

10. 9. The head wearable device of claim 8, wherein at least a first internal coupling grating is configured to internally couple light corresponding to the first wavelength and a second internal coupling grating is configured to internally couple light corresponding to the second wavelength.

11. The head wearable device of claim 8 , wherein the light source is configured to emit the first wavelength at a first time and the second wavelength at a second time, the second time being different from the first time.

12. A head-wearable device as described in claim 8, wherein the internal coupling gratings of at least two of the plurality of waveguides are aligned.

13. The head wearable device of claim 8 , wherein the light source is offset from the image generator.

14. The head wearable device of claim 8 , wherein the reflector comprises a compound parabolic concentrator reflector.

15. 1. A display system comprising a single pupil light source, The single pupil light source is a reflector having an entrance aperture and an exit aperture; a micro LED array disposed proximate to the entrance aperture; Equipped with the micro LED array comprises a plurality of stripes; The plurality of stripes include: a first stripe configured to emit light having a first wavelength, the first stripe being positioned and sized according to the first wavelength; a second stripe configured to emit light having a second wavelength, the second stripe positioned and sized according to the second wavelength; a third stripe configured to emit light having a third wavelength, the third stripe being positioned and sized according to the third wavelength; and Equipped with The single-pupil light source is configured to emit a first light, the first light having the first wavelength, the second wavelength, or the third wavelength.

16. 16. The display system of claim 15, wherein the reflector comprises a compound parabolic concentrator reflector.

17. 16. The display system of claim 15, wherein the micro LED array comprises a plurality of micro LED sources, the micro LED sources having at least one of a circular shape, a rectangular shape, and a square shape.

18. 16. The display system of claim 15, wherein the micro LED array is configured to emit light at at least three wavelengths.

19. 16. The display system of claim 15, wherein the micro LED array is positioned across the entrance aperture.

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