Apparatus, system, and method for eye tracking based on speckle patterns formed by coherent light

Abstract

A system comprising (1) an eyewear device dimensioned to be worn by a user and configured to provide an artificial-reality experience to the user, (2) at least one coherent light source coupled to the eyewear device and configured to illuminate an eye of a user, (3) at least one optical sensor configured to generate data that represents images of the eye, and (4) circuitry configured to (A) identify a representation of at least one speckle pattern in the data and (B) determine at least one attribute of the eye based at least in part on the speckle pattern. Various other apparatuses, systems, and methods are also disclosed.

Description

APPARATUS, SYSTEM, AND METHOD FOR EYE TRACKING BASED ON SPECKLE PATTERNS FORMED BY COHERENT LIGHTCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit of and priority to U.S. provisional patent application Ser. No. 63 / 554,121 filed February 15, 2024.TECHNICAL FIELD

[0002] The present disclosure is generally directed to apparatuses, systems, and methods for eye tracking based on speckle patterns formed by coherent light.BACKGROUND

[0003] Current eye-tracking techniques are often incorporated into different types of eyewear devices, such as head-mounted displays (HMDs). For example, these techniques typically include physical components that observe a viewer’s eye movement to determine what the viewer is looking at within a display. In some implementations, these components may include one or more lights that shine onto the viewer’s eyes and one or more optical sensors (e.g., cameras) that observe how the one or more lights are reflected by the viewer’s eyes.SUMMARY

[0004] According to a first aspect, there is provided an eyewear device comprising: at least one coherent light source configured to illuminate an eye of a user; at least one optical sensor configured to generate data that represents images of the eye; and circuitry configured to: identify a representation of at least one speckle pattern in the data; and determine at least one attribute of the eye based at least in part on the speckle pattern.

[0005] The circuitry may be further configured to perform at least one action in response to the at least one attribute of the eye.

[0006] The circuitry may be further configured to track the eye based at least in part on the at least one attribute of the eye.

[0007] The at least one attribute of the eye may comprise at least one of: a state of the eye; an orientation of the eye; a movement of the eye; a position of the eye; or motion dynamics in certain regions of the eye.

[0008] The at least one coherent light source may be further configured to illuminate a surface of the eye that exhibits one or more irregularities that cause light waves to form the speckle pattern by interfering with one another.

[0009] The at least one coherent light source may be further configured to illuminate the surface of the eye with the light waves. The speckle pattern may be formed by a combination of a reference wave and a scattering of the light waves produced by the one or more irregularities.

[0010] The circuitry may be further configured to: detect at least one change in the speckle pattern; and determine the at least one attribute of the eye based at least in part on the atleast one change in the speckle pattern.

[0011] The at least one optical sensor may be further configured to: generate a first data set that represents a first image of the eye at a first moment in time; and generate a second data set that represents a second image of the eye at a second moment in time. The circuitry may be further configured to: detect the at least one change in the speckle pattern based at least in part on the first data set and the second data set; and determine the at least one attribute of the eye based at least in part on the at least one change in the speckle pattern.

[0012] The circuitry may be further configured to: detect at least one change in the speckle pattern; and determine that the eye has moved in a certain direction based at least in part on the at least one change in the speckle pattern.

[0013] The circuitry may be further configured to determine that the eye has moved a certain amount in the certain direction based at least in part on the at least one change in the speckle pattern.

[0014] The circuitry may be further configured to determine that the user is looking at a certain target based at least in part on the speckle pattern.

[0015] According to a second aspect, there is provided a system comprising the eyewear device of the first aspect dimensioned to be worn by a user and configured to provide an artificial-reality experience to the user.

[0016] According to a third aspect, there is provided a method comprising: directing, via circuitry, a coherent light source to illuminate an eye of a user; receiving, via the circuitry, data that represents images of the eye from an optical sensor; identifying, via the circuitry, a representation of at least one speckle pattern in the data; and determining, via the circuitry, at least one attribute of the eye based at least in part on the speckle pattern.BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings illustrate a number of examples and are parts of the specification. Together with the following description, the Drawings demonstrate and explain various principles of the instant disclosure.

[0018] FIG. 1 is an illustration of an exemplary apparatus for eye tracking based on speckle patterns formed by coherent light.

[0019] FIG. 2 is an illustration of an exemplary artificial-reality system for eye tracking based on speckle patterns formed by coherent light.

[0020] FIG. 3 is an illustration of an exemplary implementation of an apparatus for eye tracking based on speckle patterns formed by coherent light.

[0021] FIG. 4 is an illustration of an exemplary artificial-reality system for eye tracking based on speckle patterns formed by coherent light.

[0022] FIG. 5 is an illustration of an exemplary artificial-reality system for eye tracking based on speckle patterns formed by coherent light.

[0023] FIG. 6 is an illustration of an exemplary artificial-reality system for eye tracking based on speckle patterns formed by coherent light.

[0024] FIG. 7 is a flowchart of an exemplary method for integrating antennas that support multiple wireless technologies into artificial-reality devices.

[0025] FIG. 8 is an illustration of exemplary AR system that may be used in connection with embodiments of this disclosure.

[0026] FIG. 9 is an illustration of an exemplary VR system that may be used in connection with embodiments of this disclosure.

[0027] FIG. 10 an illustration of an exemplary system that incorporates an eye-tracking subsystem capable of tracking a user’s eye(s).

[0028] FIG. 1 1 is a more detailed illustration of various aspects of the eye-tracking subsystem illustrated in FIG. 10.

[0029] While the examples described herein are susceptible to various modifications and alternative forms, specific examples have been shown by way of example in the drawings and will be described in detail herein. However, the examples described herein are not intended to be limited to the particular forms disclosed. Rather, the instant disclosure covers all modifications, combinations, equivalents, and alternatives falling within this disclosure.DETAILED DESCRIPTION

[0030] In some examples, in-field eye-tracking systems may include and / or represent waveguides and / or hot mirrors that lead to certain design constraints and / or tradeoffs. For example, on the one hand, eyewear device manufacturers may want to improve light coupling efficiency and / or visibility or to reduce system complexity and / or costs. To do so, eyewear device manufacturers may try to decrease and / or minimize the optical bandwidth by using narrowband light sources, such as lasers and / or vertical-cavity surface-emitting laser (VCSEL) devices. However, on the other hand, eyewear device manufacturers may want to improve the image quality of the eye being tracked. To do so, eyewear device manufacturers may try to avoid narrowband light sources because they introduce speckle patterns that tend to degrade the image quality and / or disrupt traditional eye-tracking algorithms.

[0031] In some examples, to achieve the benefits of narrowband light sources without succumbing to the corresponding drawbacks, eyewear device manufacturers may repurpose speckle patterns produced by the narrowband light sources to supplement the traditional imaging information and / or data about the eye. In other words, instead of impairing the eyetracking algorithm, the speckle patterns may actually supply the optical sensors and / or corresponding circuitry with additional information and / or data capable of being used to enhance the eye-tracking performance.

[0032] Various eye-tracking designs and / or systems may implement the technology necessary to repurpose speckle patterns produced by the narrowband light sources for eye-tracking enhancement. For example, an eyewear device may include and / or implement one or more cameras and / or point scanning sensors that directly capture, detect, and / or sense speckle patterns as illuminated on the eye of a user by a laser or VCSEL device. In another example, an eyewear device may include and / or implement one or more cameras coupled to a waveguide whose aperture is used for speckle-pattern image collection. In a further example, an eyewear device may include and / or implement a hot mirror, near-infrared mirror, and / or holographic combiner that reflects near-infrared light and transmits visible light to facilitate speckle-pattern image collection.

[0033] In some examples, an eyewear device may modify and / or alter traditional eye-tracking algorithms to ensure that spatial and temporal statistics of the speckle field illuminated on the eye are captured. As a result of such capturing, the eyewear device may obtain and / or derive additional signals for segmentation and / or relative displacement (e.g., in the x-direction, y- direction, and / or z-direction) of the eye and / or periocular surfaces. For example, coherent light may illuminate a surface of the eye that exhibits imperfections and / or irregularities. In this example, the coherent light may reflect and / or scatter off these imperfections and / or irregularities, thereby causing light waves to interfere with each other to form a granular speckle pattern.

[0034] In some examples, each unique surface of the eye may produce and / or promote a unique speckle pattern when illuminated by the coherent light. As a result, the eyewear device may analyze, process, and / or evaluate the speckle patterns to track otherwise featureless surfaces of the eye, such as the sclera and / or white of the eye. For example, when coherent light illuminates a featureless and / or rough surface of the eye, the coherent light forms a speckle pattern due to interference of the scattered waves. In this example, the speckle pattern may uniquely identify and / or be used to determine a specific state and / or position of the surface of the eye.

[0035] In some examples, the eyewear device may track the state, position, and / or orientation of the eye or its features based at least in part on changes in the speckle pattern. For example, the eyewear device may compare speckle patterns at different moments in time to one another. In this example, the eyewear device may identify and / or determine changes in the state, position, and / or orientation of the eye based at least in part on differences in the speckle patterns from one moment to another.

[0036] In some examples, the sensitivity of the speckle patterns may be high enough that even tiny changes in the surface position and / or orientation are detectible and / or perceptible by the eyewear device. In one example, the eyewear device may implement speckle interferometry in which the coherent light source emits light that includes a reference wave that is combined with a scattered wave from the eye’s surface to produce the speckle pattern.

[0037] In some examples, the eyewear device may include and / or represent a coherent lightsource (e.g., a laser and / or a VCSEL device) that illuminates the eye of a user. In one example, the eyewear device may include and / or represent an optical sensor (e.g., a camera or a point scanning sensor) that generates data that represents images of the user’s eye. In this example, the eyewear device may include and / or represent circuitry may identify at least one speckle pattern in the plurality of images. Additionally or alternatively, the circuitry may determine at least one attribute (e.g., the state, position, movement, motion dynamics, and / or orientation) of the eye based at least in part on the speckle pattern.

[0038] In some examples, the circuitry may track the eye’s movement based at least in part on the attribute of the eye. In one example, the circuitry may perform one or more actions in response to the attribute of the eye. Examples of such actions include, without limitation, generating virtual content presented via optical elements (e.g., lenses), modifying virtual content presented via optical elements, modifying and / or updating components and / or features of an imaging pipeline, monitoring eye health, predicting gaze motions or directions, initiating a telephone call, sending a text message or other communication, executing a computing command and / or instruction, combinations of one or more of the same, and / or any other suitable actions.

[0039] In some examples, the eye-tracking system, enhanced by speckle pattern analysis, may be used to improve security through advanced spoof protection and / or authentication methods. By analyzing unique speckle patterns generated by the eye's surface and periocular regions, the eye-tracking system may create a robust biometric profile for user authentication. This profile may leverage the distinct characteristics of speckle patterns, which are difficult to replicate, to provide a secure method for verifying user identity. Additionally, continuous monitoring of speckle pattern dynamics may detect attempts at spoofing and / or liveness detection, such as the use of artificial eyes or recorded eye movements, ensuring that only the genuine user gains access to secure content and / or systems.

[0040] In some examples, optical elements may be inserted and / or installed in the eyewear frame. In other words, optical elements may be coupled to, incorporated in, and / or held by the eyewear frame. In one example, optical elements may be configured and / or arranged to provide one or more virtual features for presentation to a user wearing the eyewear frame. These virtual features may be driven, influenced, and / or controlled by the circuitry and / or one or more wireless technologies supported by eyewear device.

[0041] In some examples, the optical elements may each include and / or represent optical stacks, lenses, and / or films. In one example, the optical elements may each include and / or represent various layers that facilitate and / or support the presentation of virtual features and / or elements that overlay real-world features and / or elements. Additionally or alternatively, the optical elements may each include and / or represent one or more screens, lenses, and / or fully or partially see-through components. Examples of the optical elements include, withoutlimitation, electrochromic layers, dimming stacks, transparent conductive layers (such as indium tin oxide films), metal meshes, antennas, transparent resin layers, lenses, films, combinations or variations of one or more of the same, and / or any other suitable optical elements.

[0042] In some examples, the circuitry may include and / or represent one or more electrical and / or electronic circuits capable of processing, applying, modifying, transforming, displaying, transmitting, receiving, and / or executing data for the eyewear device. In one example, the circuitry may be electrically and / or communicatively coupled to the optical elements, the coherent light source(s), and / or the optical sensor(s). In this example, the coherent light sources and / or optical sensors may each be integrated into and / or secured to the eyewear frame and / or optical elements. In certain implementations, the optical sensors may be configured and / or programmed to detect coherent light emitted by the coherent light sources and / or reflected by the user’s eyes (e.g., in the form of speckle patterns).

[0043] In some examples, the eyewear device may include and / or represent an HMD and / or an artificial-reality device or system. Artificial reality may provide a rich, immersive experience in which users are able to interact with virtual objects and / or environments in one way or another. In this context, artificial reality may constitute and / or represent a form of reality that has been altered by virtual objects for presentation to a user. Such artificial reality may include and / or represent virtual reality (VR), AR, mixed reality, hybrid reality, or some combination and / or variation of one or more of the same.

[0044] The following will provide, with reference to FIGS. 1-6, detailed descriptions of exemplary apparatuses, devices, systems, components, and corresponding configurations for eye tracking based on speckle patterns formed by coherent light. In addition, detailed descriptions of methods for eye tracking based on speckle patterns formed by coherent light in connection with FIG. 7. The discussion corresponding to FIGS. 8-11 will provide detailed descriptions of types of exemplary artificial-reality devices, wearables, and / or associated systems capable of eye tracking based on speckle patterns formed by coherent light.

[0045] FIG. 1 illustrates an exemplary apparatus 100 capable of spreading and / or expanding light directed toward displays in eyewear devices. As illustrated in FIG. 1 , apparatus 100 may include and / or represent an eyewear frame 102 dimensioned to be worn by a user. In some examples, eyewear frame 102 may include and / or be equipped with one or more coherent light sources, one or more optical sensors, and / or circuitry. For example, eyewear frame 102 may include and / or be equipped with a coherent light source 104, an optical sensor 108, and / or circuitry 106. In this example, coherent light source 104 may illuminate an eye of a user, and / or optical sensor 108 may generate and / or produce data 1 10 that represents images of the user’s eye. In certain implementations, circuitry 106 may be communicatively and / or electrically coupled or connected to coherent light source 104 and / or optical sensor 108.

[0046] Although not necessarily illustrated in this way in FIG. 1 , apparatus 100 may be equipped with multiple eye-tracking devices and / or features for tracking both eyes of the user. Additionally or alternatively, although not necessarily illustrated in this way in FIG. 1 , apparatus 100 may include and / or represent multiple instances of coherent light source 104 and / or optical sensor 108 for tracking each of the user’s eyes.

[0047] In some examples, circuitry 106 may receive, retrieve, and / or obtain data 1 10 from optical sensor 108. In one example, circuitry 106 may identify and / or detect a representation of at least one speckle pattern in data 1 10. In this example, such a speckle pattern may constitute, establish, and / or represent a constellation or grouping of illuminated features (e.g., imperfections, irregularities, etc.) on a surface of the user’s eye. Additionally or alternatively, such a speckle pattern may constitute, establish, and / or represent a granular interference arrangement and / or capillary map produced by the superposition of various light waves of the same frequency but different phases. In certain implementations, circuitry 106 may determine and / or discover certain attributes and / or features of the user’s eye based at least in part on the speckle pattern.

[0048] In some examples, circuitry 106 may track and / or follow the movements of the user’s eye based at least in part on the attributes and / or features of the user’s eye. Examples of such attributes and / or features include, without limitation, states of the user’s eye, orientations of the user’s eye, movements of the user’s eye, positions of the user’s eye, motion dynamics in certain regions (e.g., the periocular area) of the eye, combinations or variations of one or more of the same, and / or any other suitable attributes and / or features of the user’s eye.

[0049] In some examples, circuitry 106 may perform, execute, and / or implement one or more actions in response to and / or based on the attributes and / or features of the user’s eye. Examples of such actions include, without limitation, generating virtual content presented via optical elements (e.g., lenses), modifying virtual content presented via optical elements, monitoring eye health, predicting gaze motions or directions, initiating a telephone call, sending a text message or other communication, executing a computing command and / or instruction, combinations of one or more of the same, and / or any other suitable actions.

[0050] In some examples, the eye-tracking system, enhanced by speckle pattern analysis, may monitor user health by detecting signs of fatigue, eye strain, tremors, and the speed of pupil dilation through precise eye motion and / or speed detection. Variations in eye motion speed and / or pupil dilation, as captured by speckle patterns, may indicate fatigue, stress, and / or cognitive load, prompting the eye-tracking system to adjust display settings and / or suggest breaks to alleviate discomfort. Furthermore, the detection of change in dynamics of micro-movements, such as tremors, may provide early indicators of neurological conditions.

[0051] In some examples, coherent light source 104 may illuminate a surface of the eye that exhibits one or more features and / or irregularities that cause light waves to form the specklepattern by interfering with one another. For example, coherent light source 104 may subject the surface of the user’s eye to electromagnetic radiation and / or light waves. In one example, the speckle pattern may form from and / or be generated by a combination of a reference wave and / or a scattering of light waves produced by the features and / or irregularities on the surface of the user’s eye. In certain implementations, some changes in the speckle pattern may indicate and / or suggest that the user’s eye has moved and / or rotated in one direction or another.

[0052] In some examples, circuitry 106 may analyze and / or evaluate data 110 over time. In one example, circuitry 106 may detect and / or identify one or more changes in the speckle pattern from one moment in time to another based at least in part on data 110. Additionally or alternatively, circuitry 106 may determine and / or discover certain attributes of the user’s eye based at least in part on the change(s) in the speckle pattern.

[0053] As a specific example, circuitry 106 may determine, discover, and / or detect that the user’s eye has moved and / or rotated to the left, to the right, upward, downward, diagonally, etc. In this example, circuitry 106 may make and / or arrive at this determination, discovery, and / or detection by comparing and / or evaluating data 110 over time (e.g., from one moment to another).

[0054] In some examples, optical sensor 108 may generate and / or produce one set of data that represents an image of the user’s eye at one moment in time. In such examples, optical sensor 108 may subsequently generate and / or produce another set of data that represents another image of the user’s eye at another moment in time. In one example, circuitry 106 may detect and / or identify one or more changes in the speckle pattern reflected by and / or established on the surface of the user’s eye based at least in part on those sets of data. For example, circuitry 106 may detect and / or identify one or more changes in the speckle pattern by comparing those sets of data relative to one another. In this example, circuitry 106 may determine, discover, and / or detect certain attributes, states, and / or features of the user’s eye based at least in part on the change(s) in the speckle pattern.

[0055] In some examples, circuitry 106 may determine that the user’s eye has moved in a certain direction relative to a previous position based at least in part on the change(s) in the speckle pattern. Additionally or alternatively, circuitry 106 may determine that the user’s eye has moved in a certain amount relative to the previous position based at least in part on the change(s) in the speckle pattern. In certain implementations, circuitry 106 may determine that the user is looking at a certain target (e.g., a virtual feature, a real-world feature, object, etc.) based at least in part on the speckle pattern.

[0056] In some examples, circuitry 106 may apply and / or implement various processing techniques on data 110 to detect and / or measure motion and / or speed of the user’s eye. Examples of such processing techniques include, without limitation, image segmentation,optical flow, computer vision, speckle interferometry, speckle displacement, wavelength multiplexing, spatial frequency analyses, global cross-correlation analysis, speckle-contrast analyses, triangulation, Fourier profilometry, phase-shifting profilometry, spectral differentiation, combinations or variations of one or more of the same, and / or any other suitable processing techniques.

[0057] In some examples, circuitry 106 may determine that the user’s eye has moved based at least in part on spatial and / or temporal statistics of the speckle pattern. Additionally or alternatively, circuitry 106 may examine and / or analyze additional signals derived from the spatial or temporal statistics. By doing so, circuitry 106 may perform, implement, and / or achieve image segmentation of the speckle pattern represented in the frames of data 1 10. In one example, circuitry 106 may determine and / or measure the relative displacement of the user’s eye (e.g., XYZ motion and / or translation) from one image frame to the next image frame based at least in part on the image segmentation.

[0058] In some examples, circuitry 106 may perform and / or implement a global crosscorrelation analysis, a speckle-contrast analysis, and / or an optical flow on speckle patterns represented in sequential frames. By doing so, circuitry 106 may detect and / or measure the velocity of motion of the user’s eye between the moments in time at which those frames were captured. Additionally or alternatively, circuitry 106 may detect, measure, and / or predict the magnitude of relative displacement of the user’s eye based at least in part on the velocity of motion of the user’s eye.

[0059] In some examples, the contrast of the speckle pattern represented in the image frames may indicate, suggest, and / or correspond to the speed at which the user’s eye is moving. For example, high-contrast, developed, and / or defined speckles may indicate, suggest, and / or correspond to relatively slow eye motion and / or a stationary eye. In another example, low- contrast, smoothed, and / or blurred speckles may indicate, suggest, and / or correspond to relatively fast eye motion.

[0060] In some examples, circuitry 106 may predict future eye motion and / or position based at least in part on one or more image frames. For example, circuitry 106 may predict the direction and / or speed of the user’s future eye motion if one or more image frames indicate that the user’s eye is currently moving in a certain direction, at a certain speed, and / or with a certain magnitude. In this example, circuitry 106 may perform, execute, and / or implement one or more actions in response to and / or based on the predicted future eye motion, direction, speed, and / or position. Examples of such actions include, without limitation, generating virtual content presented via optical elements (e.g., lenses), modifying virtual content presented via optical elements, modifying and / or updating components and / or features of an imaging pipeline, predicting gaze motions or directions, initiating a telephone call, sending a text message or other communication, executing a computing command and / or instruction,combinations of one or more of the same, and / or any other suitable actions.

[0061] In some examples, circuitry 106 may modify the eye-tracking frame rate to optimize and / or improve the efficiency and / or performance of apparatus 100 based at least in part on the user’s eye motion and / or the needs of apparatus 100. Additionally or alternatively, circuitry 106 may dynamically update the sample size and / or other parameters of the speckle pattern and / or image frames in data 1 10 to optimize and / or improve the efficiency and / or performance of apparatus 100 based at least in part on the user’s eye motion and / or the needs of apparatus 100.

[0062] In some examples, apparatus 100 may include and / or represent an HMD dimensioned to be worn by a user. In one example, the HMD may include and / or represent any type or form of display device or system integrated into eyewear frame 102. For example, the HMD may include and / or represent a pair of smart glasses and / or AR glasses. In this example, the HMD may be worn on or about the user’s face and may display virtual content, such as computergenerated objects and / or AR content, to the user.

[0063] HMDs may present and / or display content in any suitable way, including via a display screen, a liquid crystal display (LCD), a light-emitting diode (LED) display, a microLED display, a plasma display, a projector, a cathode ray tube, an optical mixer, combinations or variations of one or more of the same. HMDs may present and / or display content in one or more media formats. For example, HMDs may display video, photos, computer-generated imagery (CGI), and / or variations or combinations of one or more of the same. Additionally or alternatively, HMDs may include and / or incorporate see-through lenses that enable the user to see the user’s surroundings in addition to such computer-generated content.

[0064] In some examples, HMDs may provide diverse and / or distinctive user experiences. Some HMDs may provide virtual-reality experiences (i.e., they may display computergenerated or pre-recorded content), while other HMDs may provide real-world experiences (i.e., they may display live imagery from the physical world). HMDs may also provide any mixture of live and virtual content. For example, virtual content may be projected onto the physical world (e.g., via optical or video see-through lenses), which may result in AR and / or mixed-reality experiences.

[0065] In some examples, circuitry 106 may include and / or represent one or more electrical and / or electronic circuits capable of processing, applying, modifying, transforming, displaying, transmitting, receiving, and / or executing data and / or signals for apparatus 100. In one example, circuitry 106 may provide data and / or signaling that control activation and / or deactivation of coherent light source 104 to facilitate and / or support CGI presentation in connection with an AR application.

[0066] In some examples, circuitry 106 may launch, perform, and / or execute certain executable files, code snippets, and / or computer-readable instructions to facilitate and / orsupport eye tracking based on speckle patterns formed by coherent light. Although illustrated as a single unit in FIG. 1 , circuitry 106 may include and / or represent a collection of multiple processing units and / or electrical or electronic components that work and / or operate in conjunction with one another. In one example, circuitry 106 may include and / or represent an application-specific integrated circuit (ASIC). Additionally or alternatively, circuitry 106 may include and / or represent a central processing unit (CPU).

[0067] Additional examples of circuitry 106 include, without limitation, processing devices, microprocessors, microcontrollers, graphics processing units (GPUs), field-programmable gate arrays (FPGAs), systems on chips (SoCs), parallel accelerated processors, tensor cores, integrated circuits, chiplets, optical modules, receivers, transmitters, transceivers, optical modules, memory devices, transistors, antennas, resistors, capacitors, diodes, inductors, switches, registers, flipflops, digital logic, connections, traces, buses, semiconductor (e.g., silicon) devices and / or structures, storage devices, audio controllers, portions of one or more of the same, variations or combinations of one or more of the same, and / or any other suitable circuitry.

[0068] In some examples, circuitry 106 may direct and / or cause coherent light source 104 to emit and / or direct light to shine on and / or illuminate a surface of the user’s eye. In one example, the light may travel and / or traverse from coherent light source 104 across, through, and / or to one or more optical elements (e.g., mirrors, reflectors, films, lenses, etc.) on the way to the user’s eye. Such optical elements may diffract, refract, reflect, spread, direct, and / or expand light on the way to the user’s eye. In certain implementations, coherent light source 104 may generate and / or produce the speckle pattern on the surface of the user’s eye via the illumination.

[0069] In some examples, coherent light source 104 may include and / or represent any type or form of device capable of emitting, outputting, and / or producing coherent light and / or electromagnetic radiation. Examples of coherent light source 104 include, without limitation, laser devices, VCSEL devices, collimated light devices, fiber optics, waveguide-driven lasers, combinations or variations of one or more of the same, and / or any other suitable coherent light source.

[0070] In certain implementations, coherent light source 104 may be positioned and / or disposed on the frame of an eyewear device and / or HMD. In other implementations, coherent light source 104 may be positioned and / or disposed on an optical element and / or lens of an eyewear device and / or HMD. Although illustrated as a single unit in FIG. 1 , coherent light source 104 may include and / or represent a collection of multiple coherent light sources that work and / or operate in conjunction with one another to illuminate the user’s eye.

[0071] In some examples, optical sensor 108 may include and / or represent any type or form of device capable of capturing images and / or generating, outputting, and / or producing datathat represents such images. In one example, optical sensor 108 may include and / or represent a camera device. In another example, optical sensor 108 may include and / or represent an image scanning device.

[0072] In some examples, data 1 10 may include and / or represent a sequence of frames that capture, depict, and / or portray images of the user’s eye. In one example, data 110 may include and / or represent a first image frame captured at a first moment in time, a second image frame captured at a second moment in time, a third image frame captured at a third moment in time, etc. In this example, the first and second frames may be temporally adjacent to one another, and the second and third frames may be temporally adjacent to one another. In other words, the second frame may directly follow and / or have been taken directly after the first frame, and the third frame may directly follow and / or have been taken directly after the second frame. Put differently, the second frame may constitute the very next frame relative to the first frame, and the third frame may constitute the very next frame relative to the second frame.

[0073] FIG. 2 illustrates an exemplary artificial-reality system 200 for eye tracking based on speckle patterns formed by coherent light. In some examples, artificial-reality system 200 may include and / or represent certain components and / or features that perform and / or provide functionalities that are similar and / or identical to those described above in connection with FIG. 1. As illustrated in FIG. 2, artificial-reality system 200 may include and / or represent eyewear frame 102 that facilitates, supports, and / or provides artificial-reality experiences for a user. In one example, eyewear frame 102 may include and / or represent a front frame 202, temples 204(1) and 204(2), optical elements 206(1) and 206(2), endpieces 208(1) and 208(2), nose pads 210, and / or a bridge 212.

[0074] In some examples, optical elements 206(1) and 206(2) may be inserted and / or installed in front frame 202. In other words, optical elements 206(1) and 206(2) may be coupled to, incorporated in, and / or held by eyewear frame 102. In one example, optical elements 206(1) and 206(2) may be configured and / or arranged to provide one or more virtual features for presentation to a user wearing artificial-reality system 200. These virtual features may be driven, influenced, and / or controlled by one or more wireless technologies supported by artificial-reality system 200.

[0075] In some examples, optical elements 206(1) and 206(2) may each include and / or represent optical stacks, lenses, and / or films. In one example, optical elements 206(1) and 206(2) may each include and / or represent various layers that facilitate and / or support the presentation of virtual features and / or elements that overlay real-world features and / or elements. Additionally or alternatively, optical elements 206(1) and 206(2) may each include and / or represent one or more screens, lenses, and / or fully or partially see-through components. Examples of optical elements 206(1) and (2) include, without limitation, electrochromic layers, dimming stacks, transparent conductive layers (such as indium tinoxide films), metal meshes, antennas, transparent resin layers, lenses, films, combinations or variations of one or more of the same, and / or any other suitable optical elements.

[0076] FIG. 3 illustrates an exemplary implementation 300 of apparatus 100 for eye tracking based on speckle patterns formed by coherent light. In some examples, implementation 300 may include and / or involve certain components and / or features that perform and / or provide functionalities that are similar and / or identical to those described above in connection with either FIG. 1 or FIG. 2. As illustrated in FIG. 3, a user 302 may wear apparatus 100 for an AR experience. For example, apparatus 100 may reside on, be applied to, and / or be worn on the face of user 302.

[0077] In some examples, optical sensor 108 may be optically coupled to a visually transparent waveguide of apparatus 100 and / or eyewear frame 102. In such examples, apparatus 100 may include and / or represent an aperture 308 that facilitates and / or supports image collection and / or capture. For example, aperture 308 may be implemented on, integrated into, and / or disposed on a visually transparent waveguide of apparatus 100 and / or eyewear frame 102. In this example, the waveguide may be optically coupled between aperture 308 and optical sensor 108. This optical coupling may enable optical sensor 108 to receive imaging information representative of the speckle pattern formed on an eye 304 of user 302 via aperture 308.

[0078] In certain examples, aperture 308 may be positioned and / or located over eye 304 on optical element 206(1). In one example, this position and / or location of aperture 308 may facilitate and / or support a direct view of the eye 304 for imaging by optical sensor 108 without impairing the line of sight of user 302. In other words, rather than positioning optical sensor 108 in the optical path of user 302, apparatus 100 may implement aperture 308 over eye 304 and rely on aperture 308 to pass imaging information about eye 304 to optical sensor 108 via the waveguide.

[0079] FIG. 4 illustrates an exemplary artificial-reality system 400 that facilitates and / or supports eye tracking based on speckle patterns formed by coherent light. In some examples, artificial-reality system 400 may include and / or involve certain components and / or features that perform and / or provide functionalities that are similar and / or identical to those described above in connection with any of FIGS. 1-3. As illustrated in FIG. 4, artificial-reality system 400 may include and / or represent a waveguide 406 that optically couples optical sensor 108 to aperture 308.

[0080] In some examples, artificial-reality system 400 may include and / or represent coherent light source 104 and / or circuitry 106. In one example, optical sensor 108 may effectively scan and / or image eye 304 via information, data, and / or light captured and / or recorded via aperture 308. In this example, such information, data, and / or light may traverse and / or pass from aperture 308 to optical sensor 108 via waveguide 406. In certain implementations, coherentlight source 104 may be positioned and / or disposed on the frame of artificial-reality system 400. Additionally or alternatively, coherent light source 104 may be positioned and / or disposed on optical element 206(1) of artificial-reality system 400.

[0081] In some examples, circuitry 106 may receive, retrieve, and / or obtain data 1 10 from optical sensor 108. In one example, circuitry 106 may identify and / or detect a representation of a speckle pattern 408 in data 1 10. In this example, speckle pattern 408 may constitute, establish, and / or represent a constellation, grouping, and / or field of illuminated features on the surface of eye 304.

[0082] In some examples, coherent light source 104 may illuminate the surface of eye 304, thereby effectively forming and / or producing speckle pattern 408. In one example, speckle pattern 408 may include, be influenced by, and / or account for irregularities 404 of eye 304. In this example, circuitry 106 may use the data that corresponds to and / or represents irregularities 404 as reference points to track the movements, states, and / or positions of eye 304.

[0083] FIG. 5 illustrates an exemplary artificial-reality system 500 that facilitates and / or supports eye tracking based on speckle patterns formed by coherent light. In some examples, artificial-reality system 500 may include and / or involve certain components and / or features that perform and / or provide functionalities that are similar and / or identical to those described above in connection with any of FIGS. 1-4. As illustrated in FIG. 5, artificial-reality system 500 may include and / or represent optical sensor 108 physically fixed and / or coupled to eyewear frame 102.

[0084] In certain implementations, optical sensor 108 may be positioned and / or placed to avoid obstructing and / or impairing an optical path 502 and / or line of sight of the user’s eye. In one example, from this positioning and / or placement, optical sensor 108 may be able to directly obtain, capture, and / or record imaging information about the user’s eye. In this example, optical sensor 108 may do so directly by imaging the user’s eye without the use of an external waveguide and / or aperture.

[0085] FIG. 6 illustrates an exemplary artificial-reality system 600 that facilitates and / or supports eye tracking based on speckle patterns formed by coherent light. In some examples, artificial-reality system 600 may include and / or involve certain components and / or features that perform and / or provide functionalities that are similar and / or identical to those described above in connection with any of FIGS. 1-5. As illustrated in FIG. 6, artificial-reality system 600 may include and / or represent optical sensor 108 physically fixed and / or coupled to eyewear frame 102.

[0086] In some examples, artificial-reality system 600 may include and / or represent an optical interface 604 and / or a reflective surface 606. In one example, optical interface 604 may include and / or represent a holographic combiner that facilities and / or combines virtual andreal-world elements for viewing by a user. Additionally or alternatively, reflective surface 606 may include and / or represent a hot mirror and / or a semitransparent surface or film deposited on and / or applied to optical element 206(1) of eyewear frame 102. In certain implementations, optical interface 604 may be positioned and / or placed between the user’s eye and reflective surface 606 or optical element 206(1).

[0087] In some examples, reflective surface 606 may be configured and / or designed to reflect infrared and / or near infrared light but to transmit visible light. In one example, speckle pattern 408 may be represented and / or captured by light 608. In this example, light 608 may constitute and / or represent infrared light that is reflected by reflective surface 606. Reflective surface 606 may reflect and / or direct light 608 toward optical sensor 108. Accordingly, optical sensor 108 may scan, image, capture, and / or record data representative of speckle pattern 408 based at least in part on light 608. Optical sensor 108 may then transfer such data to circuitry 106 for processing and / or eye tracking.

[0088] In some examples, the various apparatuses, devices, and systems described in connection with FIGS. 1-6 may include and / or represent one or more additional circuits, components, and / or features that are not necessarily illustrated and / or labeled in FIGS. 1-6. For example, the apparatuses, devices, and systems illustrated in FIGS. 1-6 may also include and / or represent additional analog and / or digital circuitry, onboard logic, transistors, radiofrequency (RF) transmitters, RF receivers, RF transceivers, antennas, resistors, capacitors, diodes, inductors, switches, registers, flipflops, digital logic, connections, traces, buses, semiconductor (e.g., silicon) devices and / or structures, processing devices, storage devices, circuit boards, sensors, packages, substrates, housings, waveguides, combinations or variations of one or more of the same, and / or any other suitable components. In certain implementations, one or more of these additional circuits, components, and / or features may be inserted and / or applied between any of the existing circuits, components, and / or features illustrated in FIGS. 1-6 consistent with the aims and / or objectives described herein. Accordingly, the couplings and / or connections described with reference to FIGS. 1-6 may be direct connections with no intermediate components, devices, and / or nodes or indirect connections with one or more intermediate components, devices, and / or nodes.

[0089] In some examples, the phrase “to couple” and / or the term “coupling”, as used herein, may refer to a direct connection and / or an indirect connection. For example, a direct coupling between two components may constitute and / or represent a coupling in which those two components are directly connected to each other by a single node that provides continuity from one of those two components to the other. In other words, the direct coupling may exclude and / or omit any additional components between those two components.

[0090] Additionally or alternatively, an indirect coupling between two components may constitute and / or represent a coupling in which those two components are indirectly connectedto each other by multiple nodes that fail to provide continuity from one of those two components to the other. In other words, the indirect coupling may include and / or incorporate at least one additional component between those two components. In some examples, one or more components and / or features illustrated in FIGS. 1-6 may be excluded and / or omitted from the various apparatuses, devices, and / or systems described in connection with FIGS. 1- 6.

[0091] FIG. 7 is a flow diagram of an exemplary method 700 for eye tracking based on speckle patterns formed by coherent light. In one example, the steps shown in FIG. 7 may be performed during operation of an artificial-reality device. Additionally or alternatively, the steps shown in FIG. 7 may incorporate and / or involve various sub-steps and / or variations consistent with one or more of the descriptions provided above in connection with FIGS. 1-6.

[0092] As illustrated in FIG. 7, method 700 may include and / or involve the step of directing, via circuitry, a coherent light source to illuminate an eye of a user (710). Step 710 may be performed in a variety of ways, including any of those described above in connection with FIGS. 1-6. For example, circuitry incorporated in an artificial-reality device may direct and / or cause a coherent light source to illuminate an eye of a user.

[0093] In some examples, method 700 may also include the step of receiving, via the circuitry, data that represents images of the eye from an optical sensor (720). Step 720 may be performed in a variety of ways, including any of those described above in connection with FIGS. 1-6. For example, the circuitry incorporated in the artificial-reality device may receive and / or obtain data that represents images of the eye from an optical sensor.

[0094] In some examples, method 700 may also include the step of identifying, via the circuitry, a representation of at least one speckle pattern in the data (730). Step 730 may be performed in a variety of ways, including any of those described above in connection with FIGS. 1-6. For example, the circuitry incorporated in the artificial-reality device may identify and / or detect a representation of at least one speckle pattern in the data.

[0095] In some examples, method 700 may also include the step of determining, via the circuitry, at least one attribute of the eye based at least in part on the speckle pattern (740). Step 740 may be performed in a variety of ways, including any of those described above in connection with FIGS. 1 -6. For example, the circuitry incorporated in the artificial-reality device may determine at least one attribute of the eye based at least in part on the speckle pattern.

[0096] Embodiments of the present disclosure may include or be implemented in conjunction with various types of artificial-reality systems. Artificial reality is a form of reality that has been adjusted in some manner before presentation to a user, which may include, for example, a VR, an AR, a mixed reality, a hybrid reality, or some combination and / or derivative thereof. Artificial-reality content may include completely computer-generated content or computer-generated content combined with captured (e.g., real-world) content. The artificial-reality content may include video, audio, haptic feedback, or some combination thereof, any of which may be presented in a single channel or in multiple channels (such as stereo video that produces a three-dimensional (3D) effect to the viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof, that are used to, for example, create content in an artificial reality and / or are otherwise used in (e.g., to perform activities in) an artificial reality.

[0097] Artificial-reality systems may be implemented in a variety of different form factors and configurations. Some artificial-reality systems may be designed to work without near-eye displays (NEDs). Other artificial-reality systems may include an NED that also provides visibility into the real world (such as, e.g., AR system 800 in FIG. 8) or that visually immerses a user in an artificial reality (such as, e.g., VR system 900 in FIG. 9). While some artificialreality devices may be self-contained systems, other artificial-reality devices may communicate and / or coordinate with external devices to provide an artificial-reality experience to a user. Examples of such external devices include handheld controllers, mobile devices, desktop computers, devices worn by a user, devices worn by one or more other users, and / or any other suitable external system.

[0098] Turning to FIG. 8, AR system 800 may include an eyewear device 802 with a frame 810 configured to hold a left display device 815(A) and a right display device 815(B) in front of a user’s eyes. Display devices 815(A) and 815(B) may act together or independently to present an image or series of images to a user. While AR system 800 includes two displays, examples of this disclosure may be implemented in AR systems with a single NED or more than two NEDs.

[0099] In some examples, AR system 800 may include one or more sensors, such as sensor 840. Sensor 840 may generate measurement signals in response to motion of AR system 800 and may be located on substantially any portion of frame 810. Sensor 840 may represent one or more of a variety of different sensing mechanisms, such as a position sensor, an inertial measurement unit (IMU), a depth camera assembly, a structured light emitter and / or detector, or any combination thereof. In some examples, AR system 800 may or may not include sensor 840 or may include more than one sensor. In examples in which sensor 840 includes an IMU, the IMU may generate calibration data based on measurement signals from sensor 840. Examples of sensor 840 may include, without limitation, accelerometers, gyroscopes, magnetometers, other suitable types of sensors that detect motion, sensors used for error correction of the IMU, or some combination thereof.

[0100] In some examples, AR system 800 may also include a microphone array with a plurality of acoustic transducers 820(A)-820(J), referred to collectively as acoustic transducers 820. Acoustic transducers 820 may represent transducers that detect air pressure variationsinduced by sound waves. Each acoustic transducer 820 may be configured to detect sound and convert the detected sound into an electronic format (e.g., an analog or digital format). The microphone array in FIG. 8 may include, for example, ten acoustic transducers: 820(A) and 820(B), which may be designed to be placed inside a corresponding ear of the user, acoustic transducers 820(C), 820(D), 820(E), 820(F), 820(G), and 820(H), which may be positioned at various locations on frame 810, and / or acoustic transducers 820(l) and 820(J), which may be positioned on a corresponding neckband 805.

[0101] In some examples, one or more of acoustic transducers 820(A)-(J) may be used as output transducers (e.g., speakers). For example, acoustic transducers 820(A) and / or 820(B) may be earbuds or any other suitable type of headphone or speaker.

[0102] The configuration of acoustic transducers 820 of the microphone array may vary. While AR system 800 is shown in FIG. 8 as having ten acoustic transducers 820, the number of acoustic transducers 820 may be greater or less than ten. In some examples, using higher numbers of acoustic transducers 820 may increase the amount of audio information collected and / or the sensitivity and accuracy of the audio information. In contrast, using a lower number of acoustic transducers 820 may decrease the computing power required by an associated controller 850 to process the collected audio information. In addition, the position of each acoustic transducer 820 of the microphone array may vary. For example, the position of an acoustic transducer 820 may include a defined position on the user, a defined coordinate on frame 810, an orientation associated with each acoustic transducer 820, or some combination thereof.

[0103] Acoustic transducers 820(A) and 820(B) may be positioned on different parts of the user’s ear, such as behind the pinna, behind the tragus, and / or within the auricle or fossa. Or, there may be additional acoustic transducers 820 on or surrounding the ear in addition to acoustic transducers 820 inside the ear canal. Having an acoustic transducer 820 positioned next to an ear canal of a user may enable the microphone array to collect information on how sounds arrive at the ear canal. By positioning at least two of acoustic transducers 820 on either side of a user’s head (e.g., as binaural microphones), AR system 800 may simulate binaural hearing and capture a 3D stereo sound field around about a user’s head. In some examples, acoustic transducers 820(A) and 820(B) may be connected to AR system 800 via a wired connection 830, and in other examples acoustic transducers 820(A) and 820(B) may be connected to AR system 800 via a wireless connection (e.g., a BLUETOOTH connection). In still other examples, acoustic transducers 820(A) and 820(B) may not be used at all in conjunction with AR system 800.

[0104] Acoustic transducers 820 on frame 810 may be positioned in a variety of different ways, including along the length of the temples, across the bridge, above or below display devices 815(A) and 815(B), or some combination thereof. Acoustic transducers 820 may alsobe oriented such that the microphone array is able to detect sounds in a wide range of directions surrounding the user wearing the AR system 800. In some examples, an optimization process may be performed during manufacturing of AR system 800 to determine relative positioning of each acoustic transducer 820 in the microphone array.

[0105] In some examples, AR system 800 may include or be connected to an external device (e.g., a paired device), such as neckband 805. Neckband 805 generally represents any type or form of paired device. Thus, the following discussion of neckband 805 may also apply to various other paired devices, such as charging cases, smart watches, smart phones, wrist bands, other wearable devices, hand-held controllers, tablet computers, laptop computers, other external compute devices, etc.

[0106] As shown, neckband 805 may be coupled to eyewear device 802 via one or more connectors. The connectors may be wired or wireless and may include electrical and / or nonelectrical (e.g., structural) components. In some cases, eyewear device 802 and neckband 805 may operate independently without any wired or wireless connection between them. While FIG. 8 illustrates the components of eyewear device 802 and neckband 805 in example locations on eyewear device 802 and neckband 805, the components may be located elsewhere and / or distributed differently on eyewear device 802 and / or neckband 805. In some examples, the components of eyewear device 802 and neckband 805 may be located on one or more additional peripheral devices paired with eyewear device 802, neckband 805, or some combination thereof.

[0107] Pairing external devices, such as neckband 805, with AR eyewear devices may enable the eyewear devices to achieve the form factor of a pair of glasses while still providing sufficient battery and computation power for expanded capabilities. Some or all of the battery power, computational resources, and / or additional features of AR system 800 may be provided by a paired device or shared between a paired device and an eyewear device, thus reducing the weight, heat profile, and form factor of the eyewear device overall while still retaining desired functionality. For example, neckband 805 may allow components that would otherwise be included on an eyewear device to be included in neckband 805 since users may tolerate a heavier weight load on their shoulders than they would tolerate on their heads. Neckband 805 may also have a larger surface area over which to diffuse and disperse heat to the ambient environment. Thus, neckband 805 may allow for greater battery and computation capacity than might otherwise have been possible on a stand-alone eyewear device. Since weight carried in neckband 805 may be less invasive to a user than weight carried in eyewear device 802, a user may tolerate wearing a lighter eyewear device and carrying or wearing the paired device for greater lengths of time than a user would tolerate wearing a heavy standalone eyewear device, thereby enabling users to more fully incorporate artificial-reality environments into their day-to-day activities.

[0108] Neckband 805 may be communicatively coupled with eyewear device 802 and / or to other devices. These other devices may provide certain functions (e.g., tracking, localizing, depth mapping, processing, storage, etc.) to AR system 800. In the example of FIG. 8, neckband 805 may include two acoustic transducers (e.g., 820(l) and 820(J)) that are part of the microphone array (or potentially form their own microphone subarray). Neckband 805 may also include a controller 825 and a power source 835.

[0109] Acoustic transducers 820(l) and 820(J) of neckband 805 may be configured to detect sound and convert the detected sound into an electronic format (analog or digital). In the example of FIG. 8, acoustic transducers 820(l) and 820(J) may be positioned on neckband 805, thereby increasing the distance between the neckband acoustic transducers 820(l) and 820(J) and other acoustic transducers 820 positioned on eyewear device 802. In some cases, increasing the distance between acoustic transducers 820 of the microphone array may improve the accuracy of beamforming performed via the microphone array. For example, if a sound is detected by acoustic transducers 820(C) and 820(D) and the distance between acoustic transducers 820(C) and 820(D) is greater than, e.g., the distance between acoustic transducers 820(D) and 820(E), the determined source location of the detected sound may be more accurate than if the sound had been detected by acoustic transducers 820(D) and 820(E).

[0110] Controller 825 of neckband 805 may process information generated by the sensors on neckband 805 and / or AR system 800. For example, controller 825 may process information from the microphone array that describes sounds detected by the microphone array. For each detected sound, controller 825 may perform a direction-of-arrival (DOA) estimation to estimate a direction from which the detected sound arrived at the microphone array. As the microphone array detects sounds, controller 825 may populate an audio data set with the information. In examples in which AR system 800 includes an inertial measurement unit, controller 825 may compute all inertial and spatial calculations from the IMU located on eyewear device 802. A connector may convey information between AR system 800 and neckband 805 and between AR system 800 and controller 825. The information may be in the form of optical data, electrical data, wireless data, or any other transmittable data form. Moving the processing of information generated by AR system 800 to neckband 805 may reduce weight and heat in eyewear device 802, making it more comfortable to the user.

[0111] Power source 835 in neckband 805 may provide power to eyewear device 802 and / or to neckband 805. Power source 835 may include, without limitation, lithium ion batteries, lithium-polymer batteries, primary lithium batteries, alkaline batteries, or any other form of power storage. In some cases, power source 835 may be a wired power source. Including power source 835 on neckband 805 instead of on eyewear device 802 may help better distribute the weight and heat generated by power source 835.

[0112] As noted, some artificial-reality systems may, instead of blending an artificial reality with actual reality, substantially replace one or more of a user’s sensory perceptions of the real world with a virtual experience. One example of this type of system is a head-worn display system, such as VR system 900 in FIG. 9, that mostly or completely covers a user’s field of view. VR system 900 may include a front rigid body 902 and a band 904 shaped to fit around a user’s head. VR system 900 may also include output audio transducers 906(A) and 906(B). Furthermore, while not shown in FIG. 9, front rigid body 902 may include one or more electronic elements, including one or more electronic displays, one or more inertial measurement units (IMUs), one or more tracking emitters or detectors, and / or any other suitable device or system for creating an artificial-reality experience.

[0113] Artificial-reality systems may include a variety of types of visual feedback mechanisms. For example, display devices in AR system 800 and / or VR system 900 may include one or more liquid crystal displays (LCDs), light emitting diode (LED) displays, microLED displays, organic LED (OLED) displays, digital light project (DLP) micro-displays, liquid crystal on silicon (LCoS) micro-displays, and / or any other suitable type of display screen. These artificial-reality systems may include a single display screen for both eyes or may provide a display screen for each eye, which may allow for additional flexibility for varifocal adjustments or for correcting a user’s refractive error. Some of these artificial-reality systems may also include optical subsystems having one or more lenses (e.g., concave or convex lenses, Fresnel lenses, adjustable liquid lenses, etc.) through which a user may view a display screen. These optical subsystems may serve a variety of purposes, including to collimate (e.g., make an object appear at a greater distance than its physical distance), to magnify (e.g., make an object appear larger than its actual size), and / or to relay (to, e.g., the viewer’s eyes) light. These optical subsystems may be used in a non-pupil-forming architecture (such as a single lens configuration that directly collimates light but results in so-called pincushion distortion) and / or a pupil-forming architecture (such as a multi-lens configuration that produces so-called barrel distortion to nullify pincushion distortion).

[0114] In addition to or instead of using display screens, some of the artificial-reality systems described herein may include one or more projection systems. For example, display devices in AR system 800 and / or VR system 900 may include micro-LED projectors that project light (using, e.g., a waveguide) into display devices, such as clear combiner lenses that allow ambient light to pass through. The display devices may refract the projected light toward a user’s pupil and may enable a user to simultaneously view both artificial-reality content and the real world. The display devices may accomplish this using any of a variety of different optical components, including waveguide components (e.g., holographic, planar, diffractive, polarized, and / or reflective waveguide elements), light-manipulation surfaces and elements (such as diffractive, reflective, and refractive elements and gratings), coupling elements, etc.Artificial-reality systems may also be configured with any other suitable type or form of image projection system, such as retinal projectors used in virtual retina displays.

[0115] The artificial-reality systems described herein may also include various types of computer vision components and subsystems. For example, AR system 800 and / or VR system 900 may include one or more optical sensors, such as two-dimensional (2D) or 3D cameras, structured light transmitters and detectors, time-of-flight depth sensors, single-beam or sweeping laser rangefinders, 3D LiDAR sensors, and / or any other suitable type or form of optical sensor. An artificial-reality system may process data from one or more of these sensors to identify a location of a user, to map the real world, to provide a user with context about real- world surroundings, and / or to perform a variety of other functions.

[0116] The artificial-reality systems described herein may also include one or more input and / or output audio transducers. Output audio transducers may include voice coil speakers, ribbon speakers, electrostatic speakers, piezoelectric speakers, bone conduction transducers, cartilage conduction transducers, tragus-vibration transducers, and / or any other suitable type or form of audio transducer. Similarly, input audio transducers may include condenser microphones, dynamic microphones, ribbon microphones, and / or any other type or form of input transducer. In some examples, a single transducer may be used for both audio input and audio output.

[0117] In some examples, the artificial-reality systems described herein may also include tactile (i.e., haptic) feedback systems, which may be incorporated into headwear, gloves, body suits, handheld controllers, environmental devices (e.g., chairs, floormats, etc.), and / or any other type of device or system. Haptic feedback systems may provide various types of cutaneous feedback, including vibration, force, traction, texture, and / or temperature. Haptic feedback systems may also provide various types of kinesthetic feedback, such as motion and compliance. Haptic feedback may be implemented using motors, piezoelectric actuators, fluidic systems, and / or a variety of other types of feedback mechanisms. Haptic feedback systems may be implemented independent of other artificial-reality devices, within other artificial-reality devices, and / or in conjunction with other artificial-reality devices.

[0118] By providing haptic sensations, audible content, and / or visual content, artificial-reality systems may create an entire virtual experience or enhance a user’s real-world experience in a variety of contexts and environments. For instance, artificial-reality systems may assist or extend a user’s perception, memory, or cognition within a particular environment. Some systems may enhance a user’s interactions with other people in the real world or may enable more immersive interactions with other people in a virtual world. Artificial-reality systems may also be used for educational purposes (e.g., for teaching or training in schools, hospitals, government organizations, military organizations, business enterprises, etc.), entertainment purposes (e.g., for playing video games, listening to music, watching video content, etc.),and / or for accessibility purposes (e.g., as hearing aids, visual aids, etc.). The embodiments disclosed herein may enable or enhance a user’s artificial-reality experience in one or more of these contexts and environments and / or in other contexts and environments.

[0119] In some examples, the systems described herein may also include an eye-tracking subsystem designed to identify and track various characteristics of a user’s eye(s), such as the user’s gaze direction. The phrase “eye tracking” may, in some examples, refer to a process by which the position, orientation, and / or motion of an eye is measured, detected, sensed, determined, and / or monitored. The disclosed systems may measure the position, orientation, and / or motion of an eye in a variety of different ways, including through the use of various optical-based eye-tracking techniques, ultrasound-based eye-tracking techniques, etc. An eye-tracking subsystem may be configured in a number of different ways and may include a variety of different eye-tracking hardware components or other computer-vision components. For example, an eye-tracking subsystem may include a variety of different optical sensors, such as two-dimensional (2D) or 3D cameras, time-of-flight depth sensors, single-beam or sweeping laser rangefinders, 3D LiDAR sensors, and / or any other suitable type or form of optical sensor. In this example, a processing subsystem may process data from one or more of these sensors to measure, detect, determine, and / or otherwise monitor the position, orientation, and / or motion of the user’s eye(s).

[0120] FIG. 10 is an illustration of an exemplary system 1000 that incorporates an eyetracking subsystem capable of tracking a user’s eye(s). As depicted in FIG. 10, system 1000 may include a light source 1002, an optical subsystem 1004, an eye-tracking subsystem 1006, and / or a control subsystem 1008. In some examples, light source 1002 may generate light for an image (e.g., to be presented to an eye 1001 of the viewer). Light source 1002 may represent any of a variety of suitable devices. For example, light source 1002 can include a two-dimensional projector (e.g., a LCoS display), a scanning source (e.g., a scanning laser), or other device (e.g., an LCD, an LED display, an OLED display, an active-matrix OLED display (AMOLED), a transparent OLED display (TOLED), a waveguide, or some other display capable of generating light for presenting an image to the viewer). In some examples, the image may represent a virtual image, which may refer to an optical image formed from the apparent divergence of light rays from a point in space, as opposed to an image formed from the light ray’s actual divergence.

[0121] In some examples, optical subsystem 1004 may receive the light generated by light source 1002 and generate, based on the received light, converging light 1020 that includes the image. In some examples, optical subsystem 1004 may include any number of lenses (e.g., Fresnel lenses, convex lenses, concave lenses), apertures, filters, mirrors, prisms, and / or other optical components, possibly in combination with actuators and / or other devices. In particular, the actuators and / or other devices may translate and / or rotate one or more of theoptical components to alter one or more aspects of converging light 1020. Further, various mechanical couplings may serve to maintain the relative spacing and / or the orientation of the optical components in any suitable combination.

[0122] In one example, eye-tracking subsystem 1006 may generate tracking information indicating a gaze angle of an eye 1001 of the viewer. In this example, control subsystem 1008 may control aspects of optical subsystem 1004 (e.g., the angle of incidence of converging light 1020) based at least in part on this tracking information. Additionally, in some examples, control subsystem 1008 may store and utilize historical tracking information (e.g., a history of the tracking information over a given duration, such as the previous second or fraction thereof) to anticipate the gaze angle of eye 1001 (e.g., an angle between the visual axis and the anatomical axis of eye 1001). In some examples, eye-tracking subsystem 1006 may detect radiation emanating from some portion of eye 1001 (e.g., the cornea, the iris, the pupil, or the like) to determine the current gaze angle of eye 1001. In other examples, eye-tracking subsystem 1006 may employ a wavefront sensor to track the current location of the pupil.

[0123] Any number of techniques can be used to track eye 1001. Some techniques may involve illuminating eye 1001 with infrared light and measuring reflections with at least one optical sensor that is tuned to be sensitive to the infrared light. Information about how the infrared light is reflected from eye 1001 may be analyzed to determine the position(s), orientation(s), and / or motion(s) of one or more eye feature(s), such as the cornea, pupil, iris, and / or retinal blood vessels.

[0124] In some examples, the radiation captured by a sensor of eye-tracking subsystem 1006 may be digitized (i.e., converted to an electronic signal). Further, the sensor may transmit a digital representation of this electronic signal to one or more processors (for example, processors associated with a device including eye-tracking subsystem 1006). Eye-tracking subsystem 1006 may include any of a variety of sensors in a variety of different configurations. For example, eye-tracking subsystem 1006 may include an infrared detector that reacts to infrared radiation. The infrared detector may be a thermal detector, a photonic detector, and / or any other suitable type of detector. Thermal detectors may include detectors that react to thermal effects of the incident infrared radiation.

[0125] In some examples, one or more processors may process the digital representation generated by the sensor(s) of eye-tracking subsystem 1006 to track the movement of eye 1001. In another example, these processors may track the movements of eye 1001 by executing algorithms represented by computer-executable instructions stored on non- transitory memory. In some examples, on-chip logic (e.g., an application-specific integrated circuit or ASIC) may be used to perform at least portions of such algorithms. As noted, eyetracking subsystem 1006 may be programmed to use an output of the sensor(s) to track movement of eye 1001. In some examples, eye-tracking subsystem 1006 may analyze thedigital representation generated by the sensors to extract eye rotation information from changes in reflections. In one example, eye-tracking subsystem 1006 may use corneal reflections or glints (also known as Purkinje images) and / or the center of the eye’s pupil 1022 as features to track over time.

[0126] In some examples, eye-tracking subsystem 1006 may use the center of the eye’s pupil 1022 and infrared or near-infrared, non-collimated light to create corneal reflections. In these examples, eye-tracking subsystem 1006 may use the vector between the center of the eye’s pupil 1022 and the corneal reflections to compute the gaze direction of eye 1001. In some examples, the disclosed systems may perform a calibration procedure for an individual (using, e.g., supervised or unsupervised techniques) before tracking the user’s eyes. For example, the calibration procedure may include directing users to look at one or more points displayed on a display while the eye-tracking system records the values that correspond to each gaze position associated with each point.

[0127] In some examples, eye-tracking subsystem 1006 may use two types of infrared and / or near-infrared (also known as active light) eye-tracking techniques: bright-pupil and dark-pupil eye tracking, which may be differentiated based on the location of an illumination source with respect to the optical elements used. If the illumination is coaxial with the optical path, then eye 1001 may act as a retroreflector as the light reflects off the retina, thereby creating a bright pupil effect similar to a red-eye effect in photography. If the illumination source is offset from the optical path, then the eye’s pupil 1022 may appear dark because the retroreflection from the retina is directed away from the sensor. In some examples, bright-pupil tracking may create greater iris / pupil contrast, allowing more robust eye tracking with iris pigmentation, and may feature reduced interference (e.g., interference caused by eyelashes and other obscuring features). Bright-pupil tracking may also allow tracking in lighting conditions ranging from total darkness to a very bright environment.

[0128] In some examples, control subsystem 1008 may control light source 1002 and / or optical subsystem 1004 to reduce optical aberrations (e.g., chromatic aberrations and / or monochromatic aberrations) of the image that may be caused by or influenced by eye 1001. In some examples, as mentioned above, control subsystem 1008 may use the tracking information from eye-tracking subsystem 1006 to perform such control. For example, in controlling light source 1002, control subsystem 1008 may alter the light generated by light source 1002 (e.g., by way of image rendering) to modify (e.g., pre-distort) the image so that the aberration of the image caused by eye 1001 is reduced.

[0129] The disclosed systems may track both the position and relative size of the pupil (since, e.g., the pupil dilates and / or contracts). In some examples, the eye-tracking devices and components (e.g., sensors and / or sources) used for detecting and / or tracking the pupil may be different (or calibrated differently) for different types of eyes. For example, the frequencyrange of the sensors may be different (or separately calibrated) for eyes of different colors and / or different pupil types, sizes, and / or the like. As such, the various eye-tracking components (e.g., infrared sources and / or sensors) described herein may need to be calibrated for each individual user and / or eye.

[0130] The disclosed systems may track both eyes with and without ophthalmic correction, such as that provided by contact lenses worn by the user. In some examples, ophthalmic correction elements (e.g., adjustable lenses) may be directly incorporated into the artificialreality systems described herein. In some examples, the color of the user’s eye may necessitate modification of a corresponding eye-tracking algorithm. For example, eye-tracking algorithms may need to be modified based at least in part on the differing color contrast between a brown eye and, for example, a blue eye.

[0131] FIG. 1 1 is a more detailed illustration of various aspects of the eye-tracking subsystem illustrated in FIG. 10. As shown in this figure, an eye-tracking subsystem 1100 may include at least one source 1104 and at least one sensor 1106. Source 1 104 generally represents any type or form of element capable of emitting radiation. In one example, source 1104 may generate visible, infrared, and / or near-infrared radiation. In some examples, source 1 104 may radiate non-collimated infrared and / or near-infrared portions of the electromagnetic spectrum towards an eye 1 102 of a user. Source 1104 may utilize a variety of sampling rates and speeds. For example, the disclosed systems may use sources with higher sampling rates in order to capture fixational eye movements of a user’s eye 1102 and / or to correctly measure saccade dynamics of the user’s eye 1102. As noted above, any type or form of eye-tracking technique may be used to track the user’s eye 1 102, including optical-based eye-tracking techniques, ultrasound-based eye-tracking techniques, etc.

[0132] Sensor 1106 generally represents any type or form of element capable of detecting radiation, such as radiation reflected off the user’s eye 1 102. Examples of sensor 1 106 include, without limitation, a charge coupled device (CCD), a photodiode array, a complementary metal-oxide-semiconductor (CMOS) based sensor device, and / or the like. In one example, sensor 1106 may represent a sensor having predetermined parameters, including, but not limited to, a dynamic resolution range, linearity, and / or other characteristic selected and / or designed specifically for eye tracking.

[0133] As detailed above, eye-tracking subsystem 1 100 may generate one or more glints. As detailed above, a glint 1 103 may represent reflections of radiation (e.g., infrared radiation from an infrared source, such as source 1 104) from the structure of the user’s eye. In various examples, glint 1103 and / or the user’s pupil may be tracked using an eye-tracking algorithm executed by a processor (either within or external to an artificial-reality device). For example, an artificial-reality device may include a processor and / or a memory device in order to perform eye tracking locally and / or a transceiver to send and receive the data necessary to performeye tracking on an external device (e.g., a mobile phone, cloud server, or other computing device).

[0134] FIG. 1 1 shows an example image 1 105 captured by an eye-tracking subsystem, such as eye-tracking subsystem 1 100. In this example, image 1 105 may include both the user’s pupil 1 108 and a glint 1 1 10 near the same. In some examples, pupil 1108 and / or glint 1 1 10 may be identified using an artificial-intelligence-based algorithm, such as a computer-vision- based algorithm. In one example, image 1105 may represent a single frame in a series of frames that may be analyzed continuously in order to track the eye 1102 of the user. Further, pupil 1 108 and / or glint 1 1 10 may be tracked over a period of time to determine a user’s gaze.

[0135] In one example, eye-tracking subsystem 1 100 may be configured to identify and measure the inter-pupillary distance (IPD) of a user. In some examples, eye-tracking subsystem 1100 may measure and / or calculate the IPD of the user while the user is wearing the artificial-reality system. In these examples, eye-tracking subsystem 1 100 may detect the positions of a user’s eyes and may use this information to calculate the user’s IPD.

[0136] As noted, the eye-tracking systems or subsystems disclosed herein may track a user’s eye position and / or eye movement in a variety of ways. In one example, one or more light sources and / or optical sensors may capture an image of the user’s eyes. The eye-tracking subsystem may then use the captured information to determine the user’s inter-pupillary distance, interocular distance, and / or a 3D position of each eye (e.g., for distortion adjustment purposes), including a magnitude of torsion and rotation (i.e., roll, pitch, and yaw) and / or gaze directions for each eye. In one example, infrared light may be emitted by the eye-tracking subsystem and reflected from each eye. The reflected light may be received or detected by an optical sensor and analyzed to extract eye rotation data from changes in the infrared light reflected by each eye.

[0137] The eye-tracking subsystem may use any of a variety of different methods to track the eyes of a user. For example, a light source (e.g., infrared light-emitting diodes) may emit a dot pattern onto each eye of the user. The eye-tracking subsystem may then detect (e.g., via an optical sensor coupled to the artificial-reality system) and analyze a reflection of the dot pattern from each eye of the user to identify a location of each pupil of the user. Accordingly, the eyetracking subsystem may track up to six degrees of freedom of each eye (i.e., 3D position, roll, pitch, and yaw) and at least a subset of the tracked quantities may be combined from two eyes of a user to estimate a gaze point (i.e., a 3D location or position in a virtual scene where the user is looking) and / or an IPD.

[0138] In some cases, the distance between a user’s pupil and a display may change as the user’s eye moves to look in different directions. The varying distance between a pupil and a display as viewing direction changes may be referred to as “pupil swim” and may contribute to distortion perceived by the user as a result of light focusing in different locations as thedistance between the pupil and the display changes. Accordingly, measuring distortion at different eye positions and pupil distances relative to displays and generating distortion corrections for different positions and distances may allow mitigation of distortion caused by pupil swim by tracking the 3D position of a user’s eyes and applying a distortion correction corresponding to the 3D position of each of the user’s eyes at a given point in time. Thus, knowing the 3D position of each of a user’s eyes may allow for the mitigation of distortion caused by changes in the distance between the pupil of the eye and the display by applying a distortion correction for each 3D eye position. Furthermore, as noted above, knowing the position of each of the user’s eyes may also enable the eye-tracking subsystem to make automated adjustments for a user’s IPD.

[0139] In some examples, a display subsystem may include a variety of additional subsystems that may work in conjunction with the eye-tracking subsystems described herein. For example, a display subsystem may include a varifocal subsystem, a scene-rendering module, and / or a vergence-processing module. The varifocal subsystem may cause left and right display elements to vary the focal distance of the display device. In one example, the varifocal subsystem may physically change the distance between a display and the optics through which it is viewed by moving the display, the optics, or both. Additionally, moving or translating two lenses relative to each other may also be used to change the focal distance of the display. Thus, the varifocal subsystem may include actuators or motors that move displays and / or optics to change the distance between them. This varifocal subsystem may be separate from or integrated into the display subsystem. The varifocal subsystem may also be integrated into or separate from its actuation subsystem and / or the eye-tracking subsystems described herein.

[0140] In one example, the display subsystem may include a vergence-processing module configured to determine a vergence depth of a user’s gaze based on a gaze point and / or an estimated intersection of the gaze lines determined by the eye-tracking subsystem. Vergence may refer to the simultaneous movement or rotation of both eyes in opposite directions to maintain single binocular vision, which may be naturally and automatically performed by the human eye. Thus, a location where a user’s eyes are verged is where the user is looking and is also typically the location where the user’s eyes are focused. For example, the vergenceprocessing module may triangulate gaze lines to estimate a distance or depth from the user associated with intersection of the gaze lines. The depth associated with intersection of the gaze lines may then be used as an approximation for the accommodation distance, which may identify a distance from the user where the user’s eyes are directed. Thus, the vergence distance may allow for the determination of a location where the user’s eyes should be focused and a depth from the user’s eyes at which the eyes are focused, thereby providing information (such as an object or plane of focus) for rendering adjustments to the virtual scene.

[0141] The vergence-processing module may coordinate with the eye-tracking subsystems described herein to make adjustments to the display subsystem to account for a user’s vergence depth. When the user is focused on something at a distance, the user’s pupils may be slightly farther apart than when the user is focused on something close. The eye-tracking subsystem may obtain information about the user’s vergence or focus depth and may adjust the display subsystem to be closer together when the user’s eyes focus or verge on something close and to be farther apart when the user’s eyes focus or verge on something at a distance.

[0142] The eye-tracking information generated by the above-described eye-tracking subsystems may also be used, for example, to modify various aspect of how different computer-generated images are presented. For example, a display subsystem may be configured to modify, based on information generated by an eye-tracking subsystem, at least one aspect of how the computer-generated images are presented. For instance, the computergenerated images may be modified based on the user’s eye movement, such that if a user is looking up, the computer-generated images may be moved upward on the screen. Similarly, if the user is looking to the side or down, the computer-generated images may be moved to the side or downward on the screen. If the user’s eyes are closed, the computer-generated images may be paused or removed from the display and resumed once the user’s eyes are back open.

[0143] The above-described eye-tracking subsystems can be incorporated into one or more of the various artificial-reality systems described herein in a variety of ways. For example, one or more of the various components of system 1000 and / or eye-tracking subsystem 1100 may be incorporated into augmented-reality system 800 in FIG. 8 and / or virtual-reality system 900 in FIG. 9 to enable these systems to perform various eye-tracking tasks (including one or more of the eye-tracking operations described herein).

[0144] The process parameters and sequence of the steps described and / or illustrated herein are given by way of example only and may be varied as desired. For example, while the steps illustrated and / or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed. The various exemplary methods described and / or illustrated herein may also omit one or more of the steps described or illustrated herein or include additional steps in addition to those disclosed.

[0145] The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the examples disclosed herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the scope of the present disclosure. The examples disclosed herein should be considered in all respects illustrative and not restrictive. Reference should be made to any claims appended hereto and their equivalents indetermining the scope of the present disclosure.

[0146] Unless otherwise noted, the terms “connected to” and “coupled to” (and their derivatives), as used in the specification and / or claims, are to be construed as permitting both direct and indirect (i.e., via other elements or components) connection. In addition, the terms “a” or “an,” as used in the specification and / or claims, are to be construed as meaning “at least one of.” Finally, for ease of use, the terms “including” and “having” (and their derivatives), as used in the specification and / or claims, are interchangeable with and have the same meaning as the word “comprising.”

Claims

CLAIMS1 . An eyewear device comprising: at least one coherent light source configured to illuminate an eye of a user; at least one optical sensor configured to generate data that represents images of the eye; and circuitry configured to: identify a representation of at least one speckle pattern in the data; and determine at least one attribute of the eye based at least in part on the speckle pattern.

2. The eyewear device of claim 1 , wherein the circuitry is further configured to perform at least one action in response to the at least one attribute of the eye.

3. The eyewear device of claim 1 or 2, wherein the circuitry is further configured to track the eye based at least in part on the at least one attribute of the eye.

4. The eyewear device of any preceding claim, wherein the at least one attribute of the eye comprises at least one of: a state of the eye; an orientation of the eye; a movement of the eye; a position of the eye; or motion dynamics in certain regions of the eye.

5. The eyewear device of any preceding claim, wherein the at least one coherent light source is further configured to illuminate a surface of the eye that exhibits one or more irregularities that cause light waves to form the speckle pattern by interfering with one another.

6. The eyewear device of claim 5, wherein: the at least one coherent light source is further configured to illuminate the surface of the eye with the light waves; and the speckle pattern is formed by a combination of a reference wave and a scattering of the light waves produced by the one or more irregularities.

7. The eyewear device of any preceding claim, wherein the circuitry is further configured to: detect at least one change in the speckle pattern; and determine the at least one attribute of the eye based at least in part on the at least one change in the speckle pattern.

8. The eyewear device of claim 7, wherein: the at least one optical sensor is further configured to: generate a first data set that represents a first image of the eye at a first moment in time; andgenerate a second data set that represents a second image of the eye at a second moment in time; and the circuitry is further configured to: detect the at least one change in the speckle pattern based at least in part on the first data set and the second data set; and determine the at least one attribute of the eye based at least in part on the at least one change in the speckle pattern.

9. The eyewear device of any preceding claim, wherein the circuitry is further configured to: detect at least one change in the speckle pattern; and determine that the eye has moved in a certain direction based at least in part on the at least one change in the speckle pattern.

10. The eyewear device of claim 9, wherein the circuitry is further configured to determine that the eye has moved a certain amount in the certain direction based at least in part on the at least one change in the speckle pattern.11 . The eyewear device of any preceding claim, wherein the circuitry is further configured to determine that the user is looking at a certain target based at least in part on the speckle pattern.

12. A system comprising the eyewear device of any preceding claim dimensioned to be worn by a user and configured to provide an artificial-reality experience to the user.

13. A method comprising: directing, via circuitry, a coherent light source to illuminate an eye of a user; receiving, via the circuitry, data that represents images of the eye from an optical sensor; identifying, via the circuitry, a representation of at least one speckle pattern in the data; and determining, via the circuitry, at least one attribute of the eye based at least in part on the speckle pattern.

Images