PATENT DOCUMENT

Publication Number: US-11768379-B2
Application Number: US-202117147147-A
Country: US
Kind Code: B2

Title: Electronic device with facial sensors

Abstract:
A system may include a head-mounted device. The head-mounted device may have a head-mounted housing that includes a display. The display is configured to display an image for viewing by a user when the user&#39;s eyes are located in eye boxes adjacent to the head-mounted housing. The head-mounted housing may have a compressible opaque light seal. The light seal may have a ring shape and may block stray ambient light around the periphery of the head-mounted housing, thereby ensuring that stray light does not interfere with viewing of the image by the user. Sensors may be provided in the light seal to measure facial expressions and gather other measurements. Information on a measured facial expression of a user can be transmitted to external devices so that the external devices can update corresponding facial expressions on an avatar to reflect the user&#39;s current facial expression.

Claims:
What is claimed is: 
     
       1. A head-mounted device configured to communicate with external equipment, comprising:
 a display configured to display an image for viewing from eye boxes; 
 a head-mounted housing in which the display is mounted, wherein the head-mounted housing has a structure and a light seal that is configured to prevent stray light from interfering with viewing of the image, the light seal has opposing first and second surfaces, and the second surface is coupled to the structure; 
 a facial sensor embedded in the light seal between the first and second surfaces and that is configured to measure a facial expression, wherein a portion of the light seal is interposed between the facial sensor and the first surface; and 
 control circuitry configured to transmit information on the facial expression to external electronic equipment. 
 
     
     
       2. The head-mounted device defined in  claim 1  wherein the light seal comprises a compressible material and wherein the facial sensor comprises capacitive sensor electrodes coupled to the compressible material. 
     
     
       3. The head-mounted device defined in  claim 2  wherein the capacitive sensor electrodes are configured to measure shear forces along the light seal. 
     
     
       4. The head-mounted device defined in  claim 2  wherein the capacitive sensor electrodes are configured to gather facial force measurements. 
     
     
       5. The head-mounted device defined in  claim 1  wherein the facial sensor comprises an electromyography sensor. 
     
     
       6. The head-mounted device defined in  claim 1  wherein the facial sensor comprises a motion sensor. 
     
     
       7. The head-mounted device defined in  claim 1  wherein the facial sensor comprises a sensor selected from the group consisting of: an accelerometer, a compass, and a gyroscope. 
     
     
       8. The head-mounted device defined in  claim 1  wherein the facial sensor comprises an optical sensor. 
     
     
       9. The head-mounted device defined in  claim 8  wherein the optical sensor comprises a light-emitting device configured to emit light and a light detector configured to detect the emitted light after the emitted light has reflected from a face. 
     
     
       10. The head-mounted device defined in  claim 1  wherein the facial sensor comprises a magnetic sensor configured to measure force against the light seal. 
     
     
       11. The head-mounted device defined in  claim 1  further comprising an actuator, wherein the control circuitry is configured to adjust the light seal using the actuator in response to information gathered with the facial sensor. 
     
     
       12. The head-mounted device defined in  claim 11  wherein the actuator comprises an electromagnetic actuator. 
     
     
       13. The head-mounted device defined in  claim 11  wherein the actuator comprises a magnetorheological device. 
     
     
       14. A head-mounted device, comprising:
 a display configured to display an image for viewing from eye boxes; 
 a head-mounted housing in which the display is mounted, wherein the head-mounted housing has a ring-shaped light seal that is configured to prevent stray light from interfering with viewing of the image, wherein the light seal has a periphery, and wherein the light seal comprises a compressible member selected from the group consisting of: an elastomeric polymer member and a foam member; and 
 an optical sensor in the light seal within the periphery of the light seal, wherein the optical sensor is configured to measure an amount of pressure exerted by the head-mounted housing on a face. 
 
     
     
       15. The head-mounted device defined in  claim 14  wherein the optical sensor is configured to detect blood flow associated with facial muscles. 
     
     
       16. The head-mounted device defined in  claim 14  wherein the optical sensor comprises an optical facial sensor including an infrared light-emitting diode that emits infrared light and an infrared light detector that detects the infrared light and wherein the head-mounted device comprises control circuitry configured to perform facial expression measurement operations and health monitoring operations using information from the optical facial sensor. 
     
     
       17. A head-mounted device, comprising:
 a display configured to display an image for viewing from eye boxes; 
 a head-mounted housing in which the display is mounted, wherein the head-mounted housing has a structure and a peripheral ring-shaped light seal that is configured to prevent stray light from interfering with viewing of the image, the peripheral ring-shaped light seal has opposing first and second surfaces, and the second surface is coupled to the structure; and 
 a motion sensor embedded in the light seal that is configured to detect facial expressions, wherein a portion of the peripheral ring-shaped light seal is interposed between the motion sensor and first surface. 
 
     
     
       18. The head-mounted device defined in  claim 17  wherein the motion sensor comprises an accelerometer. 
     
     
       19. The head-mounted device defined in  claim 18  wherein the light seal comprises a compressible member. 
     
     
       20. The head-mounted device defined in  claim 17  further comprising control circuitry configured to transmit the facial expressions to external equipment that displays an avatar with the facial expressions. 
     
     
       21. A head-mounted device, comprising:
 a display configured to display an image for viewing from eye boxes; 
 a head-mounted housing, wherein the display is mounted in the head-mounted housing, the head-mounted housing has a structure and a light seal, the light seal has opposing first and second surfaces, and the second surface is coupled to the structure; and 
 a facial sensor embedded in the light seal between the first and second surfaces, wherein a portion of the light seal is interposed between the facial sensor and the first surface.

Description:
This application claims the benefit of provisional patent application No. 62/990,792, filed Mar. 17, 2020, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to electronic devices, and, more particularly, to wearable electronic devices such as head-mounted devices. 
     BACKGROUND 
     Electronic devices such as head-mounted devices have housings that are configured to be worn on a head of a user. As the user interacts with the head-mounted device, it can be difficult to gather information on the user&#39;s actions. For example, it may be difficult to determine the state of a user&#39;s facial expressions and other information on the user. This can make it challenging or impossible for a head-mounted device to respond satisfactorily to changing conditions. 
     SUMMARY 
     A system may include a head-mounted device. The head-mounted device may have a head-mounted housing. A display is configured to display an image for viewing by a user when the user&#39;s eyes are located in eye boxes adjacent to the head-mounted housing. 
     The head-mounted housing may have a compressible opaque light seal. The light seal may have a ring shape that runs along the peripheral edge of the housing. During use of the head-mounted device, the light seal rests between the user&#39;s face and the head-mounted housing. The light seal blocks stray ambient light around the periphery of the head-mounted housing, thereby preventing the stray light from interfering with viewing of the image by the user. 
     Facial sensors may be provided in the light seal to measure facial expressions and gather other measurements. Information on a measured facial expression of a user can be transmitted to external devices so that the external devices can update corresponding facial expressions on an avatar to reflect the user&#39;s current facial expression. 
     The sensors in the light seal may be formed from capacitive sensor electrodes. Capacitive sensors and other sensors in the light seal may measure contact (touch) between the light seal and a user&#39;s face, may measure applied force, and/or may measure deformation (displacement) of the light seal. 
     If desired, optical sensors may be used to measure the user&#39;s face. For example, a facial optical sensor may use an infrared light-emitting diode or other light emitter to emit light that is reflected from the user&#39;s face and measured by an infrared light detector or other detector. During changes in facial expression, blood flow through the muscles of the user&#39;s face is affected. Optical absorption of the emitted light is affected by blood flow, so an optical facial sensor based on infrared light measurements or other light measurements can measure facial expression changes. 
     Facial expression sensors may also include electromyography sensors, resistive sensors, strain gauges, accelerometers and other motion sensors, magnetic sensors, potentiometers, and other sensors. Actuators in the light seal may be controlled based on facial sensor measurements and other measurements. Facial sensor measurements and other measurements from light-seal sensors can be used for authentication, actuator adjustments, avatar control, health monitoring, sensor calibration, and other activities. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a top view of an illustrative head-mounted device in accordance with an embodiment. 
         FIG.  2    is a rear view of an illustrative head-mounted device in accordance with an embodiment. 
         FIG.  3    is a schematic diagram of an illustrative head-mounted device in accordance with an embodiment. 
         FIG.  4    is a cross-sectional view of a light seal formed from foam in accordance with an embodiment. 
         FIG.  5    is a cross-sectional view of a light seal formed from an elastomeric polymer in accordance with an embodiment. 
         FIG.  6    is a cross-sectional view of a light seal formed from multiple layers of material that have been attached to each other using layers of adhesive in accordance with an embodiment. 
         FIG.  7    is a cross-sectional view of an illustrative light seal showing illustrative locations for sensor circuitry in accordance with embodiments. 
         FIG.  8    is a cross-sectional view of an illustrative housing member with features such as recesses and protrusions for mounting sensors adjacent to a light seal in accordance with an embodiment. 
         FIG.  9    is a cross-sectional view of an illustrative light seal with an electromyography (EMG) sensor in accordance with an embodiment. 
         FIG.  10    is a cross-sectional view of an illustrative light seal with a force sensor formed from a strain gauge in accordance with an embodiment. 
         FIG.  11    is a cross-sectional view of an illustrative light seal with an optical sensor in accordance with an embodiment. 
         FIGS.  12  and  13    are cross-sectional views of an illustrative light seal with a motion sensor such as an inertial measurement unit or accelerometer in accordance with an embodiment. 
         FIG.  14    is a cross-sectional view of a light seal with capacitive sensor electrodes in accordance with an embodiment. 
         FIG.  15    is a cross-sectional view of an illustrative light seal with a shear force sensor formed from capacitive sensor electrodes in accordance with an embodiment. 
         FIG.  16    is a cross-sectional view of an illustrative light seal with a resistive force sensor in accordance with an embodiment. 
         FIG.  17    is a cross-sectional view of an illustrative linear potentiometer for measuring light seal movement in accordance with an embodiment. 
         FIG.  18    is a cross-sectional view of an illustrative magnetic sensor configuration for a light seal in accordance with an embodiment. 
         FIG.  19    is a cross-sectional side view of an illustrative head-mounted device with light seal sensors in an upright (non-tilted) orientation in accordance with an embodiment. 
         FIG.  20    is a cross-sectional side view of the head-mounted device of  FIG.  19    in a tilted position in accordance with an embodiment. 
         FIG.  21    is a side view of an illustrative actuator that may be used to adjust a light seal in accordance with an embodiment. 
         FIG.  22    is a cross-sectional side view of an illustrative magnetorheological device for adjusting a light seal in accordance with an embodiment. 
         FIG.  23    is a flow chart of illustrative operations involved in using a head-mounted device with light seal sensing circuitry in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices such as wearable electronic devices may include displays, speakers, haptic output devices, and other output devices for presenting output to users. These electronic devices may also include sensors for gathering environmental measurements, biometric data, and user input. The sensors may include one or more facial sensors. Facial sensors may, as an example, be mounted in a portion of a head-mounted device that serves as a light seal between the device and a user&#39;s face or may be mounted in other portions of a head-mounted device. 
     A top view of an illustrative head-mounted device is shown in  FIG.  1   . As shown in  FIG.  1   , head-mounted devices such as electronic device  10  may have head-mounted support structures such as housing  12 . Housing  12  may include portions (e.g., support structures  12 T) to allow device  10  to be worn on a user&#39;s head. Support structures  12 T may be formed from fabric, polymer, metal, and/or other material. Support structures  12 T may form a strap or other head-mounted support structures that help support device  10  on a user&#39;s head. A main support structure (e.g., main housing portion  12 M) of housing  12  may support electronic components such as displays  14 . Housing  12  may be configured to be worn on a head of a user and may form glasses, a hat, a helmet, goggles, and/or other head-mounted device. 
     Front face F of housing  12  may face outwardly away from a user&#39;s head and face. Opposing rear face R of housing  12  may face the user. Display  14  is mounted in housing  12 . Display  14  faces inwardly toward eye boxes  13 . During operation, a user&#39;s eyes are placed in eye boxes  13  and the user&#39;s nose is placed in nose region  15 . When the user&#39;s eyes are located in eye boxes  13 , the user may view images being displayed by display  14  through an associated optical system with lenses in housing  12 . Front face F of device  10  faces away from eye boxes  13 . 
     In some configurations, optical components such as display  14  are configured to display computer-generated content that is overlaid over real-world images (e.g., a user may view the real world through the optical components). In other configurations, which are sometimes described herein as an example, real-world light is blocked (e.g., by an opaque housing wall at front face F of housing  12  and/or other portions of device  10 ). To help ensure that displays  14 , lenses, and other inwardly facing optical components are not exposed to undesired stray light that could adversely affect image quality, housing  12  may be provided with a light seal such as light seal  12 R. 
     When device  10  is worn on a user&#39;s head, light seal  12 R rests between main housing portion  12 M (which may, as an example, be formed from rigid components such as components made of metal, rigid polymer, glass, ceramic, and/or other material) and the user&#39;s face. Light seal  12 R is opaque and thereby prevents stray ambient light from entering the interior of device  10  and interfering with the user&#39;s viewing of the image presented by display  14 . 
     To enhance user comfort, light seal  12 R may be formed from soft compressible materials that conform to a user&#39;s face. When device  10  is being worn by a user, light seal  12 R may form a light-tight boundary between the user&#39;s face and main housing portion  12 M. The portion of main housing  12 M that supports light seal  12 R may, if desired, have a curved cross-sectional profile (as shown in  FIG.  1   ). The curved shape of housing portion  12 M may help housing  12 M conform to the curved shape of the user&#39;s head. The curved section of housing portion  12 M adjacent to nose region  15  may help housing  12 M fit comfortably over a user&#39;s nose. 
       FIG.  2    is a rear view of device  10  of  FIG.  1    showing how light seal  12 R may run along the peripheral edge of main housing portion  12 M of device  10  (e.g., to form a light sealing border structure around the perimeter of housing  12  on rear face R). Housing portion  12 M may optionally have a wall portion on rear face R that runs under light seal  12 R. Light seal  12 R may have a rectangular outline, an oval outline, an outline with straight segments and curved segments, and/or other suitable shape. Light seal  12 R may be continuous (e.g., to form a light sealing ring around the outer edge of the rear of housing  12 ) or may have one or more discontinuous segments that run along the periphery of housing  12 . Configurations in which light seal  12 R has a ring shape may sometimes be described herein as an example. 
     A schematic diagram of an illustrative electronic device such as a head-mounted device or other wearable device is shown in  FIG.  3   . Device  10  of  FIG.  3    may be operated as a stand-alone device and/or the resources of device  10  may be used to communicate with external electronic equipment. As an example, communications circuitry in device  10  may be used to transmit facial expression information and/or other information to external electronic devices (e.g., wirelessly or via wired connections). Each of these external devices may include components of the type shown by device  10  of  FIG.  3   . 
     As shown in  FIG.  3   , a head-mounted device such as device  10  may include control circuitry  20 . Control circuitry  20  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  20  may be used to gather input from sensors and other input devices and may be used to control output devices. The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors and other wireless communications circuits, power management units, audio chips, application specific integrated circuits, etc. During operation, control circuitry  20  may use display  14  and other output devices in providing a user with visual output and other output. 
     To support communications between device  10  and external equipment, control circuitry  20  may communicate using communications circuitry  22 . Circuitry  22  may include antennas, radio-frequency transceiver circuitry, and other wireless communications circuitry and/or wired communications circuitry. Circuitry  22 , which may sometimes be referred to as control circuitry and/or control and communications circuitry, may support bidirectional wireless communications between device  10  and external equipment (e.g., a companion device such as a computer, cellular telephone, or other electronic device, an accessory such as a point device, computer stylus, or other input device, speakers or other output devices, etc.) over a wireless link. For example, circuitry  22  may include radio-frequency transceiver circuitry such as wireless local area network transceiver circuitry configured to support communications over a wireless local area network link, near-field communications transceiver circuitry configured to support communications over a near-field communications link, cellular telephone transceiver circuitry configured to support communications over a cellular telephone link, or transceiver circuitry configured to support communications over any other suitable wired or wireless communications link. Wireless communications may, for example, be supported over a Bluetooth® link, a WiFi® link, a wireless link operating at a frequency between 10 GHz and 400 GHz, a 60 GHz link, or other millimeter wave link, a cellular telephone link, or other wireless communications link. Device  10  may, if desired, include power circuits for transmitting and/or receiving wired and/or wireless power and may include batteries or other energy storage devices. For example, device  10  may include a coil and rectifier to receive wireless power that is provided to circuitry in device  10 . 
     Device  10  may include input-output devices such as devices  24 . Input-output devices  24  may be used in gathering user input, in gathering information on the environment surrounding the user, and/or in providing a user with output. Devices  24  may include one or more displays such as display  14 . Display  14  may be an organic light-emitting diode display, a liquid crystal display, a microelectromechanical systems display (e.g., a scanning mirror display), a display having a pixel array formed from crystalline semiconductor light-emitting diode dies (sometimes referred to as microLEDs), and/or other display. 
     Sensors  16  in input-output devices  24  may include force sensors (e.g., strain gauges, capacitive force sensors, resistive force sensors, etc.), audio sensors such as microphones, touch and/or proximity sensors such as capacitive sensors (e.g., a two-dimensional capacitive touch sensor integrated into display  14 , a two-dimensional capacitive touch sensor overlapping display  14 , and/or a touch sensor that forms a button, trackpad, or other input device not associated with a display), and other sensors. If desired, sensors  16  may include optical sensors such as optical sensors that emit and detect light, ultrasonic sensors, optical touch sensors, optical proximity sensors, and/or other touch sensors and/or proximity sensors, monochromatic and color ambient light sensors, image sensors, fingerprint sensors, iris scanning sensors, retinal scanning sensors, and other biometric sensors, temperature sensors, sensors for measuring three-dimensional non-contact gestures (“air gestures”), pressure sensors, sensors for detecting position, orientation, and/or motion (e.g., accelerometers, magnetic sensors such as compass sensors, gyroscopes, and/or inertial measurement units that contain some or all of these sensors), health sensors such as blood oxygen sensors, heart rate sensors, blood flow sensors, and/or other health sensors, radio-frequency sensors, depth sensors (e.g., structured light sensors and/or depth sensors based on stereo imaging devices that capture three-dimensional images), optical sensors such as self-mixing sensors and light detection and ranging (lidar) sensors that gather time-of-flight measurements, humidity sensors, moisture sensors, gaze tracking sensors, electromyography sensors to sense muscle activation, facial sensors, and/or other sensors. In some arrangements, device  10  may use sensors  16  and/or other input-output devices to gather user input. For example, buttons may be used to gather button press input, touch sensors overlapping displays can be used for gathering user touch screen input, touch pads may be used in gathering touch input, microphones may be used for gathering audio input, accelerometers may be used in monitoring when a finger contacts an input surface and may therefore be used to gather finger press input, etc. 
     If desired, electronic device  10  may include additional components (see, e.g., other devices  18  in input-output devices  24 ). The additional components may include haptic output devices, actuators for moving movable housing structures, audio output devices such as speakers, light-emitting diodes for status indicators, light sources such as light-emitting diodes that illuminate portions of a housing and/or display structure, other optical output devices, and/or other circuitry for gathering input and/or providing output. Device  10  may also include a battery or other energy storage device, connector ports for supporting wired communication with ancillary equipment and for receiving wired power, and other circuitry. 
     Light seal  12 R may be formed from one or more materials. These materials may include soft materials that deform (e.g., by compressing, flexing, etc.). This allows light seal  12 R to change shape in response to applied pressure from the portions of the user&#39;s face that contact and press against these materials. The ability of light seal  12 R to deform when device  10  is being worn on a user&#39;s head and housing  12  is pressing against the user&#39;s face may help enhance user comfort. 
       FIG.  4    is a cross-sectional side view of light seal  12 R in an illustrative configuration in which light seal  12 R is formed from open-cell or closed-cell foam containing voids (air pockets)  32 . In the example of  FIG.  5   , light seal  12 R is formed from a ring-shaped strip of elastomeric polymer (e.g., silicone, etc.). To ensure that light seal  12 R is sufficiently soft to be compressed to conform to surface height variations across the user&#39;s face, it may be desirable for light seal  12 R to be formed from one or more materials with a Young&#39;s modulus of elasticity (elastic modulus) of less than 0.1 MPa, less than 1 MPa, or less than 10 MPa (as examples). 
     If desired, more than one material may be incorporated into light seal  12 R. As shown in  FIG.  6   , for example, light seal  12 R may be formed from inner layer  36  and outer layer  38 . Layers  36  and  38  may have ring shapes that run along a ring-shaped protruding edge portion of housing portion  12 M on rear face R of device  10  or other supporting portion of housing  12 . Adhesive  40  may be used to attach layers  36  and  38  together and may be used to attach light seal  12 R to housing portion  12 M. The structure(s) that make up light seal  12 R may be opaque. For example, light seal  12 R may be formed from black foam, silicone or other elastomeric polymers that contain dark colorant (e.g., black dye or pigment, etc.), and/or other light-blocking materials. With this type of configuration, light seal  12 R may block stray light and thereby prevent ambient light in the environment surrounding device  10  such as stray visible light, stray infrared light, and/or stray ultraviolet light from reaching the interior of device  10  while device  10  is being worn on a user&#39;s face. 
     Sensors such as facial sensors may be placed at one or more locations in light seal  12 R. Light seal  12 R may also be provided with one or more openings or other features to accommodate sensors. Consider, as an example, light sensor  12 R of  FIG.  7   . As shown in  FIG.  7   , light seal  12 R may have a first surface such as surface  50  that is attached to housing  12 M and a second surface such as surface  52  that is configured to rest against a user&#39;s face during use of device  10 . Light seal  12 R may be formed from light seal material  46  (e.g., foam, elastomeric material, and/or other compressible material). Light seal  12 R may be formed from a ring-shaped member that rests against a ring-shaped peripheral wall on rear face R of housing portion  12 M. To accommodate sensors such as facial sensors, light seal  12 R may be provided with holes  42  that pass partially through seal  12 R (from surface  50  and/or surface  52  of material  46 ), through-holes  42  that pass completely through material  46  of seal  12 R (e.g., cylindrical openings that pass from surface  50  to surface  52 ), slot-shaped openings  44  that pass completely through material  46  from surface  50  to surface  52  and thereby divide the ring of material  46  forming seal  12 R, and/or slot-shaped openings  44  that extend partly through material  46  from surface  52  or from surface  50 . Sensors such as facial sensors may be placed at illustrative locations such as locations  48  (e.g., at the upper or lower surfaces of openings in seal  12 R, embedded in the middle of material  46 , at surface  50 , at surface  52 , etc.). 
       FIG.  8    is a cross-sectional view of a housing portion such as ring-shaped housing wall structure  12 M′ formed by a rearwardly protruding edge portion of housing portion  12 M or other portion of housing  12 . Structure  12 M′ may extend toward the user&#39;s face around the periphery of housing portion  12 M on rear face R and may have a rear surface  58  that faces the user&#39;s face. Light seal  12 R may be attached to surface  58  using adhesive (as an example). Structure  12 M′ may have protrusions such as protrusion  56  and/or openings such as recess  54  in surface  58  and optional recess  54  in protrusion  56  to receive facial sensors or other sensors (e.g., sensors at locations such as locations  48 ). Any of the openings and protrusions associated with surface  58  of structure  12 M′ may be aligned with any of the holes and/or slots in material  46  of light seal  12 R of  FIG.  7   . 
     Facial sensors may be used to monitor the movement and location of the skin on the user&#39;s face, thereby allowing device  10  to gather information such as facial features (e.g., for biometric authentication operations), facial expressions (e.g., for controlling an avatar), device orientation (e.g., so that sensor data from other sensors may be calibrated), skin-related health data (e.g., data such as information on moisture, temperature, blood oxygen content, heart rate, blood flow, skin color, and other information that may be used in health-related applications), skin pressure (e.g., pressure information that can be used in automatically adjusting the fit of device  10  on the user&#39;s head), and/or other information associated with a user&#39;s face. 
     If desired, rear-facing image sensors in housing portion  12 M may be used to monitor parts of the user&#39;s face. The presence of light seal  12 R may tend to restrict the field of view of such sensors. To expand the coverage of these sensors and/or to gather information other than that available with rear-facing image sensors, one or more sensors  16  (e.g., facial sensors) may be incorporated into device  10  within light seal  12 R (e.g., at locations  48  of  FIGS.  7  and/or  8   ). A single sensor element may be located at a single point along the length of light seal  12 R or multiple sensor elements may be provided along the length of light seal  12 R to provide additional sensor data. For example, an array of sensors (sensor elements) may be formed along the length of light seal  12 R to gather sensor information along the periphery of housing  12 . 
     Any suitable sensors may be used in light seal  12 R to measure facial data (e.g., one or more of sensors  16  and/or other sensors). 
     In the illustrative configuration of  FIG.  9   , electrodes  60  (e.g., metal patches and/or other conductive structures) have been formed on rearwardly facing surface  52  of light seal  12 R. During operation, electrodes  60  may contact the skin of the user&#39;s face. Control circuitry  20  ( FIG.  3   ) may use electrodes  60  to sense electrical activity due to muscle activity in the user&#39;s face. For example, electrodes  60  may form an electromyography (EMG) sensor. With an electromyography facial sensor, facial movement (e.g., when a user smiles) can be electrically measured. 
     Another illustrative facial sensor arrangement is shown in  FIG.  10   . In the example of  FIG.  10   , a force sensor has been formed by embedding strain gauge  62  in light seal  12 R. As the user wears device  10 , the user&#39;s face will apply pressure to light seal  12 R and will tend to deform light seal  12 R. Deformations of light seal  12 R (twisting, bending, etc.) may arise both from the user&#39;s facial shape and changes to the user&#39;s facial expression and/or other real-time changes to the shape of the user&#39;s face. Strain gauge  62  may measure deformations to light seal  12 R in portions of light seal  12 R in the vicinity of strain gauge  62  (e.g., portions of light seal  12 R that overlap strain gauge  62 ). 
     In the example of  FIG.  11   , a facial sensor has been formed from optical components. The sensor of  FIG.  11    includes light emitter  64  and light detector  72 . Light emitter  64  may be a light-emitting diode, laser, lamp, or other light source that emits light  66  towards the skin of the user&#39;s face (face  70 ). Light detector  72  may be a photodetector such as a photodiode. Light detector  72  may measure light  66  after light  66  has reflected (specularly and/or diffusely) from the skin of face  70  (see, e.g., reflected light  68 ). Light  66  (and light  70 ) may be infrared light, visible light, and/or ultraviolet light. In some configurations, the emitted light penetrates face  70  and can therefore measure skin attributes associated with the user&#39;s blood. These attributes may include blood flow, blood oxygen level, and heart rate. Muscle activity may, as an example, affect blood flow in the user&#39;s face that can be measured by measuring infrared light absorption or other light absorption with an optical sensor. As another example, when a patch of skin in face  70  is subjected to pressure from surface  52 , some of the blood near that patch of skin will be forced away, causing the patch of skin to appear lighter in color (less red). Accordingly, an optical sensor such as the sensor of  FIG.  11    can be used to measure how much pressure is being exerted against face  70 . If desired, optical sensors that measure how much emitted light is reflected back towards the sensor may serve as proximity sensors. Detector  72  may also make light absorption measurements (associated with the amount of blood present in face  70 ) to detect facial conditions such as blushing. Blood content and/or other attributes affecting skin hue may, if desired, be assessed by providing detector  72  with multiple color channels and the ability to make spectral measurements. 
     In the example of  FIGS.  12  and  13   , a sensor (sensor  80 ) that measures position, orientation, and/or motion such as an inertial measurement unit (e.g., an accelerometer, compass, and/or gyroscope) has been incorporated into light seal  12 R. When light seal  12 R is not deformed, sensor  74  nominally has an upright orientation as shown in  FIG.  13   . When light seal  12 R is deformed as shown in  FIG.  13   , sensor  74  can measure the angle of deflection of sensor  74  resulting from the deformation of light seal  12 R (e.g., angle MA in the example of  FIG.  13   ). Motion of sensor  74  can be detected using an accelerometer (e.g., to detect when seal  12 R is deformed inwardly by pressure from the user&#39;s face or is deformed outwardly when facial pressure is released and/or to detect movement of sensor  80  along the length of seal  12 R due to shearing forces). 
     If desired, capacitive sensing techniques may be used for forming facial sensors. Consider, as an example, the sensor of  FIG.  14   . As shown in  FIG.  14   , capacitive electrodes may be embedded in light seal  12 R (see, e.g., electrodes  74 ), may be formed on surface  52  (see, e.g., electrodes  76 ), and/or may be formed on surface  50  (see, e.g., electrodes  78 ). Control circuitry  20  may use one or more of these capacitive sensor electrodes to make self-capacitance and/or mutual capacitance measurements. These measurements may be used to produce touch sensor data, force sensor data, and/or displacement data (e.g., data associated with the thickness of seal  12 R). For example, when electrodes  74  are compressed towards each other, the capacitance between electrodes  74  will rise in proportion to the applied force (e.g., electrodes  74  form a force sensor and measure displacement). As another example, when skin is placed against electrodes  76 , changes in measured capacitance reflect the contact (touch) of the skin against electrodes  76  (e.g., electrodes  76  form a touch sensor). 
     In some capacitive sensor arrangement, shear forces (forces along the length of seal  12 R rather than parallel to the surface normal of surface  52 ) may be measured. An illustrative shear force sensor formed from capacitive sensor electrodes  82  is shown in  FIG.  15   . Initially, when no shearing forces are applied by the user&#39;s face to light seal  12 R, electrodes  82  overlap and exhibit a first capacitance value. When shear force is applied to surface  52  in direction  84 , the capacitor electrode  82  on surface  52  moves to position  82 ′, which is out of alignment with the electrode on housing portion  12 M. This reduces the measured capacitance from the first capacitance value to a lower second capacitance value that is proportional to the amount of applied shear force. 
       FIG.  16    is a cross-sectional view of light seal  12 R in an illustrative configuration in which a facial sensor has been implemented using a resistive sensor. As shown in  FIG.  16   , electrodes  92  and material  94  (part of the material of light seal  12 R or separate material) are formed in light seal  12 R. When pressure is applied to material  94  to compress material  94 , the resistance of material  94  changes. Control circuitry  20  can measure the resistance between electrodes  90 . Force measurements (the amount of pressure applied to seal  12 R by the user&#39;s face) can be determined from the changes in resistance that are detected. In this way, the resistive sensor can serve as a touch and/or a force sensor and/or may measure changes in the thickness of seal  12 R. If desired, the sensor of  FIG.  16    and/or other sensors that measure touch, force (and corresponding amounts of displacement), and/or other attributes indicative of the present of the user&#39;s face against seal  12 R may be used as face presence detectors (e.g., to detect when device  10  is being worn by a user and to detect when device  10  is not being worn by a user). 
       FIG.  17    is a cross-sectional side view of an illustrative facial sensor formed from a linear potentiometer. Potentiometer  96  has first portion  100  with a shaft that moves in and out of second portion  98 . The amount that the shaft extends into portion  98  affects the measured resistance of potentiometer  96 . Potentiometer  96  may be placed within light seal  12 R. When light seal  12 R is compressed, the shaft of portion  100  may be forced into portion  98  and the resulting resistance change (and therefore a measure of the applied force) can be determined by control circuitry  20 . When used in this way, potentiometer  96  may serve to measure touch, force, and/or displacement in seal  12 R. 
     If desired, facial sensors for light seal  12 R may be formed using magnetic sensor arrangements. As shown in  FIG.  18   , light seal  12 R may, as an example, be provided with an array of magnets  104  (e.g., permanent magnets, magnetized portions of light seal  12 R, and/or other magnetized structures). Each magnet  104  may have a corresponding magnetic sensor  106  located at a fixed location relative to housing portion  12 M. Sensors  106  may be, as an example, Hall effect magnetic sensors. When a given one of magnets  104  is pressed inwardly due to facial force on light seal  12 R, a corresponding increase in magnetic field may be measured by an associated magnetic sensor  106 . In this way, the magnetic sensor arrangement of  FIG.  18    may measure touch, force, and/or displacement of light seal  12 R. 
       FIGS.  19  and  20    show how light seal facial sensors may be used to measure the orientation of device  10  relative to a user. In the examples of  FIGS.  19  and  20   , facial sensors (e.g., capacitive sensors serving as force and displacement sensors) that measure the local thickness of light seal  12 R have been placed in light seal  12 R. In the configuration of  FIG.  19   , the user&#39;s face  110  is oriented vertically (e.g., the user is facing straight ahead) and device  10  is resting normally on the user&#39;s head. In this scenario, a first sensor measures that light seal  12 R has a thickness D 1  near the top of the user&#39;s head and has a thickness D 2  near the bottom of the user&#39;s head. If the user&#39;s head is tilted downward during use of device  10 , device  10  and housing  12  will tilt at an angle A away from vertical, as shown in  FIG.  20   . The weight of housing  12  and the components of device  10  will cause the amount of force at the top and bottom of the light seal to change when housing  12  is tilted at angle A. In particular, the lower portion of seal  12 R may tend to swing away from face  110 , thereby reducing pressure on this portion of seal  12 R and increasing D 4  to a value larger than D 2 . Displacement value D 3  may, in turn, become smaller than D 1  of  FIG.  19   . Because of the changes of the thickness of light seal  12 R, housing  12  will tilt slightly relative to face  110 , which will tend to misorient display  14  and lenses associated with display  14  relative to the user&#39;s eyes. By using the measured values of D 4  and D 3  relative to the original values of D 2  and D 1 , the amount of shift in the orientation of display  14  relative to the user&#39;s eyes can be determined. Control circuitry  20  can then issue commands to display  14  and/or other components in device  10  (e.g., actuators) to adjust device  10  and/or to shift the displayed image on display  14  and/or otherwise modify the content being displayed on display  14  to compensate for the measured amount of change in display orientation (e.g., control circuitry  20  can calibrate display  14  and/or locally change the thickness of seal  12 R to compensate for measured changes in display orientation based on the measured facial sensor data). 
     Control circuitry  20  may use actuators to adjust the size, shape, stiffness, and/or other attributes of light seal  12 R. For example, actuators may be used to adjust light seal  12 R of  FIG.  20    so that D 4  is equal to D 2  and so that D 3  is equal to D 1 , thereby ensuring that the user&#39;s display  14  is oriented in a desired direction.  FIG.  21    is a cross-sectional side view of an illustrative actuator. As shown in  FIG.  21   , actuator  112  may include a first portion  114  and a second portion  116 . Second portion  116  may move relative to portion  114  in response to control commands received from control circuitry  20  at control signal input  118 . For example, in response to a command to extend portion  116 , portion  116  may move to location  116 ′. Actuator  112 , which may be embedded in light seal  12 R, may be a piezoelectric actuator formed from electroactive polymer or ceramic piezoelectric material or may be an electromagnetic actuator. For example, actuator  112  may be an electromagnetic system such as a solenoid system or other electromagnetic actuator system, may be based on a motor (e.g., a stepper motor). In general, actuator  112  may be any suitable type of actuator (electromagnetic, piezoelectric, thermal, etc.). 
     In the example of  FIG.  22   , actuator  120  is a magnetorheological device. Magnetorheological devices may be based on magnetorheological elastomers, magnetorheological fluids (e.g., fluid in a pocket in seal  12 R), and/or other materials that exhibit a change in elastic modulus as a function of applied magnetic field (the magnetorheological effect). In the example of  FIG.  22   , light seal  12 R is formed from an elastomeric polymer. Magnetic particles  122  are embedded in this polymer. Adjustable magnetic field sources  124  (e.g., coils forming electromagnets that are controlled by control circuitry  20 ) are placed adjacent to light seal  12 R. When control circuitry  20  adjusts the magnetic fields produced by sources  124 , the magnetic fields applied to light seal  12 R are changed and the modulus of light seal  12 R changes. This allows seal  12 R to serve as an electrically controlled actuator to adjust the position (e.g., the thickness) and/or modulus of seal  12 R. 
       FIG.  23    is a flow chart of illustrative operations associated with operating device  10 . During the operations of block  200 , control circuitry  20  can gather sensor measurements from one or more sensors  16  in device  10  such as facial sensors and/or other sensors  16  in light seal  12 R and/or facial image sensors or other sensors  16  located in other portions of housing  12 M. An array of facial sensors may, for example, extend along the seal  12 R (e.g., in a ring around the periphery of housing  12 M). Different sensors measure different portions of the user&#39;s face and gather information such as facial pressure, facial movement (vertical movements toward and away from seal  12 R, shear movements along the surface of seal  12 R, etc.), facial shape (from the measured thickness of seal  12 R at locations along its length), and/or other facial information (skin color, muscle activity, temperature, hear rate, blood flow, blood oxygen level, etc.). 
     During the operations of block  202 , device  10  may, if desired, use the information gathered about the user&#39;s face to authenticate the user. Control circuitry  20  may, for example, compare the facial measurements to known facial measurements previously registered for a particular user. In this way, the user&#39;s identity can be confirmed before device  10  provides the user with access to user-specific content and device functions. 
     During the operations of block  204 , facial sensor measurements (e.g., displacements of the type described in connection with  FIGS.  19  and  20   ) may be used to adjust a display (e.g., to compensate for misalignment, etc.). 
     During the operations of block  206 , actuators in seal  12 R may be adjusted based on facial sensor measurements. For example, discomfort associated with locations on seal  12 R that have elevated amounts of facial pressure can be reduced by selectively decreasing seal thickness in those locations. 
     During the operations of block  208 , health tracking measurements may be used to update a health monitoring application, to issue alerts for a user (“your heart rate is 120 bpm”), and/or to take other suitable health related actions. As an example, if a monitored health-related sensor reading deviates from expected limits, the user may be presented with visual and/or audible alert messages. 
     During the operations of block  210 , skin movement on the user&#39;s face can be used to determine the user&#39;s facial expression and to track how the user&#39;s facial expression is changing. If, for example, shear movement upward near the corners of the user&#39;s mouth is measured by the facial sensors in seal  12 R, control circuitry  20  can determine that the user is making a smile. A computer-generated representation of the user (e.g., an avatar) that is being controlled by control circuitry  20  can be provided with a facial expression that is updated to include a corresponding smile. If the user stops smiling, the avatar can be updated in real time accordingly. 
     Facial expression data from the facial sensors in light seal  12 R may be used separately from any facial expression data gathered by a rearwardly-facing camera in device  10  and/or may be used to supplement facial expression data from an image sensor in device  10  (e.g., to enhance accuracy). By ensuring that the avatar&#39;s facial expression tracks the user&#39;s real-world facial expression, the user&#39;s emotions may be accurately conveyed to others who are viewing the avatar. The avatar that is presented may be displayed for the user on display  14  and/or may be displayed for others on other displays (e.g., by transmitting facial expression information to other equipment such as one or more external electronic devices that wirelessly communicate with device  10 ). As an example, in response to detecting a facial expression using (at least partly) facial sensor data from light seal  12 R, control circuitry  20  may transmit information on the user&#39;s current measured facial expression to a computer, head-mounted device, and/or other electronic device of one or more people other than the user in real time so that the electronic devices of those people can update the displayed avatar accurately in real time. 
     Other actions may be taken in response to measured facial sensor data, if desired (block  212 ). As an example, video playback may be automatically commenced when a facial sensor detects that a user has placed device  10  on the user&#39;s head and/or video playback may be automatically stopped when a facial sensor detects that the user has removed device  10  from the user&#39;s head. 
     These activities that may be taken by device  10  based on facial sensor measurements from sensors in seal  12 R are illustrative. In general, any suitable actions that may be taken in device  10  may be taken based partly or fully on facial sensor measurements. If desired, facial sensor measurements from sensors in light seal  12 R may be supplemented and/or replaced using sensors in device  10  that are not associated with light seal  12 R (e.g., image sensors and/or other facial sensors in main housing portion  12 R). Moreover, sensor data from non-light-seal sensors and light seal facial sensors may be used together (e.g., this data may be fused to help refine and/or confirm the actions to be taken). Configurations in which device  10  takes action based solely on sensor measurements from facial sensors in light seal  12 R are illustrative. 
     As described above, one aspect of the present technology is the gathering and use of information such as information from input-output devices. The present disclosure contemplates that in some instances, data may be gathered that includes personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, twitter ID&#39;s, home addresses, data or records relating to a user&#39;s health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, username, password, biometric information, or any other identifying or personal information. 
     The present disclosure recognizes that the use of such personal information, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver targeted content that is of greater interest to the user. Accordingly, use of such personal information data enables users to calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. For instance, health and fitness data may be used to provide insights into a user&#39;s general wellness, or may be used as positive feedback to individuals using technology to pursue wellness goals. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the United States, collection of or access to certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA), whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services or anytime thereafter. In another example, users can select not to provide certain types of user data. In yet another example, users can select to limit the length of time user-specific data is maintained. In addition to providing “opt in” and “opt out” options, the present disclosure contemplates providing notifications relating to the access or use of personal information. For instance, a user may be notified upon downloading an application (“app”) that their personal information data will be accessed and then reminded again just before personal information data is accessed by the app. 
     Moreover, it is the intent of the present disclosure that personal information data should be managed and handled in a way to minimize risks of unintentional or unauthorized access or use. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, including in certain health related applications, data de-identification can be used to protect a user&#39;s privacy. De-identification may be facilitated, when appropriate, by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or specificity of data stored (e.g., collecting location data at a city level rather than at an address level), controlling how data is stored (e.g., aggregating data across users), and/or other methods. 
     Therefore, although the present disclosure broadly covers use of information that may include personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data. 
     Physical environment: A physical environment refers to a physical world that people can sense and/or interact with without aid of electronic systems. Physical environments, such as a physical park, include physical articles, such as physical trees, physical buildings, and physical people. People can directly sense and/or interact with the physical environment, such as through sight, touch, hearing, taste, and smell. 
     Computer-generated reality: in contrast, a computer-generated reality (CGR) environment refers to a wholly or partially simulated environment that people sense and/or interact with via an electronic system. In CGR, a subset of a person&#39;s physical motions, or representations thereof, are tracked, and, in response, one or more characteristics of one or more virtual objects simulated in the CGR environment are adjusted in a manner that comports with at least one law of physics. For example, a CGR system may detect a person&#39;s head turning and, in response, adjust graphical content and an acoustic field presented to the person in a manner similar to how such views and sounds would change in a physical environment. In some situations (e.g., for accessibility reasons), adjustments to characteristic(s) of virtual object(s) in a CGR environment may be made in response to representations of physical motions (e.g., vocal commands). A person may sense and/or interact with a CGR object using any one of their senses, including sight, sound, touch, taste, and smell. For example, a person may sense and/or interact with audio objects that create 3D or spatial audio environment that provides the perception of point audio sources in 3D space. In another example, audio objects may enable audio transparency, which selectively incorporates ambient sounds from the physical environment with or without computer-generated audio. In some CGR environments, a person may sense and/or interact only with audio objects. Examples of CGR include virtual reality and mixed reality. 
     Virtual reality: A virtual reality (VR) environment refers to a simulated environment that is designed to be based entirely on computer-generated sensory inputs for one or more senses. A VR environment comprises a plurality of virtual objects with which a person may sense and/or interact. For example, computer-generated imagery of trees, buildings, and avatars representing people are examples of virtual objects. A person may sense and/or interact with virtual objects in the VR environment through a simulation of the person&#39;s presence within the computer-generated environment, and/or through a simulation of a subset of the person&#39;s physical movements within the computer-generated environment. 
     Mixed reality: In contrast to a VR environment, which is designed to be based entirely on computer-generated sensory inputs, a mixed reality (MR) environment refers to a simulated environment that is designed to incorporate sensory inputs from the physical environment, or a representation thereof, in addition to including computer-generated sensory inputs (e.g., virtual objects). On a virtuality continuum, a mixed reality environment is anywhere between, but not including, a wholly physical environment at one end and virtual reality environment at the other end. In some MR environments, computer-generated sensory inputs may respond to changes in sensory inputs from the physical environment. Also, some electronic systems for presenting an MR environment may track location and/or orientation with respect to the physical environment to enable virtual objects to interact with real objects (that is, physical articles from the physical environment or representations thereof). For example, a system may account for movements so that a virtual tree appears stationery with respect to the physical ground. Examples of mixed realities include augmented reality and augmented virtuality. Augmented reality: an augmented reality (AR) environment refers to a simulated environment in which one or more virtual objects are superimposed over a physical environment, or a representation thereof. For example, an electronic system for presenting an AR environment may have a transparent or translucent display through which a person may directly view the physical environment. The system may be configured to present virtual objects on the transparent or translucent display, so that a person, using the system, perceives the virtual objects superimposed over the physical environment. Alternatively, a system may have an opaque display and one or more imaging sensors that capture images or video of the physical environment, which are representations of the physical environment. The system composites the images or video with virtual objects, and presents the composition on the opaque display. A person, using the system, indirectly views the physical environment by way of the images or video of the physical environment, and perceives the virtual objects superimposed over the physical environment. As used herein, a video of the physical environment shown on an opaque display is called “pass-through video,” meaning a system uses one or more image sensor(s) to capture images of the physical environment, and uses those images in presenting the AR environment on the opaque display. Further alternatively, a system may have a projection system that projects virtual objects into the physical environment, for example, as a hologram or on a physical surface, so that a person, using the system, perceives the virtual objects superimposed over the physical environment. An augmented reality environment also refers to a simulated environment in which a representation of a physical environment is transformed by computer-generated sensory information. For example, in providing pass-through video, a system may transform one or more sensor images to impose a select perspective (e.g., viewpoint) different than the perspective captured by the imaging sensors. As another example, a representation of a physical environment may be transformed by graphically modifying (e.g., enlarging) portions thereof, such that the modified portion may be representative but not photorealistic versions of the originally captured images. As a further example, a representation of a physical environment may be transformed by graphically eliminating or obfuscating portions thereof. Augmented virtuality: an augmented virtuality (AV) environment refers to a simulated environment in which a virtual or computer-generated environment incorporates one or more sensory inputs from the physical environment. The sensory inputs may be representations of one or more characteristics of the physical environment. For example, an AV park may have virtual trees and virtual buildings, but people with faces photorealistically reproduced from images taken of physical people. As another example, a virtual object may adopt a shape or color of a physical article imaged by one or more imaging sensors. As a further example, a virtual object may adopt shadows consistent with the position of the sun in the physical environment. 
     Hardware: there are many different types of electronic systems that enable a person to sense and/or interact with various CGR environments. Examples include head mounted systems, projection-based systems, heads-up displays (HUDs), vehicle windshields having integrated display capability, windows having integrated display capability, displays formed as lenses designed to be placed on a person&#39;s eyes (e.g., similar to contact lenses), headphones/earphones, speaker arrays, input systems (e.g., wearable or handheld controllers with or without haptic feedback), smartphones, tablets, and desktop/laptop computers. A head mounted system may have one or more speaker(s) and an integrated opaque display. Alternatively, a head mounted system may be configured to accept an external opaque display (e.g., a smartphone). The head mounted system may incorporate one or more imaging sensors to capture images or video of the physical environment, and/or one or more microphones to capture audio of the physical environment. Rather than an opaque display, a head mounted system may have a transparent or translucent display. The transparent or translucent display may have a medium through which light representative of images is directed to a person&#39;s eyes. The display may utilize digital light projection, OLEDs, LEDs, μLEDs, liquid crystal on silicon, laser scanning light sources, or any combination of these technologies. The medium may be an optical waveguide, a hologram medium, an optical combiner, an optical reflector, or any combination thereof. In one embodiment, the transparent or translucent display may be configured to become opaque selectively. Projection-based systems may employ retinal projection technology that projects graphical images onto a person&#39;s retina. Projection systems also may be configured to project virtual objects into the physical environment, for example, as a hologram or on a physical surface. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20210112
Publication Date: 20230926
Grant Date: 20230926
Priority Date: 20200317
Inventors: HOSSAIN, MUHAMMAD F.
RESNICK, SAMUEL A.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/011", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/166", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/172", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0093", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/014", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06V40/166", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/174", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/011", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/166", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06V40/172", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 77747915