PATENT DOCUMENT

Publication Number: US-11719937-B2
Application Number: US-202117230341-A
Country: US
Kind Code: B2

Title: Head-mounted electronic device with self-mixing sensors

Abstract:
A head-mounted device may have a head-mounted housing and optical components supported by the head-mounted housing. The optical components may include cameras, movable optical modules, and other components. Each optical module may include a display that displays an image and a lens that provides the image to a corresponding eye box. Optical self-mixing sensors may be included in the optical modules and other portions of the head-mounted device to measure changes in optical component position. In response to detecting a change in optical component position, actuators in the device may be adjusted to move the optical components or other action may be taken to compensate for the change.

Claims:
What is claimed is: 
     
       1. A head-mounted device, comprising:
 a head-mounted housing; 
 at least one optical module in the head-mounted housing, wherein the optical module has a display and has a lens that is configured to present an image from the display to an eye box; 
 an optical self-mixing sensor configured to measure distance to the lens; and 
 an actuator configured to adjust the lens based on the measured distance. 
 
     
     
       2. The head-mounted device defined in  claim 1  wherein the actuator is configured to move the lens in response to the measured distance. 
     
     
       3. The head-mounted device defined in  claim 2  wherein the lens has a planar portion and wherein the optical self-mixing sensor is configured to emit a beam of light that reflects from the planar portion back to the optical self-mixing sensor. 
     
     
       4. The head-mounted device defined in  claim 2  wherein the optical module comprises a lens barrel configured to support the lens and wherein the optical self-mixing sensor is configured to measure the distance to the lens by measuring a distance between the optical self-mixing sensor and the lens barrel. 
     
     
       5. The head-mounted device defined in  claim 2  wherein the lens has a lens surface and wherein the optical self-mixing sensor is configured to measure the distance to the lens by emitting light that reflects from the surface and detecting the reflected emitted light. 
     
     
       6. The head-mounted device defined in  claim 2  wherein the distance measured by the optical self-mixing sensor is a separation between the lens and the display. 
     
     
       7. The head-mounted device defined in  claim 2  wherein the optical self-mixing sensor is configured to measure lateral movement of the lens relative to the optical self-mixing sensor independently of measuring separation between the lens and the display. 
     
     
       8. The head-mounted device defined in  claim 2 , wherein the actuator is configured to tilt the lens about an axis in response to the measured distance. 
     
     
       9. The head-mounted device defined in  claim 2 , wherein the actuator is configured to move the lens towards the display in response to the measured distance. 
     
     
       10. The head-mounted device defined in  claim 2 , wherein the lens is separated from the display in a first direction and wherein the actuator is configured to move the lens in a second direction that is orthogonal to the first direction in response to the measured distance. 
     
     
       11. A head-mounted device, comprising:
 a head-mounted housing; 
 at least one optical module in the head-mounted housing, wherein the optical module has a display and has a lens that is configured to present an image from the display to an eye box; 
 an optical self-mixing sensor configured to measure distance to the lens; and 
 an actuator configured to move the lens in response to the measured distance, wherein the optical self-mixing sensor comprises a laser diode configured to emit light having a wavelength of 800-1100 nm. 
 
     
     
       12. A head-mounted device, comprising:
 a head-mounted housing; 
 optical modules supported in the head-mounted housing, wherein each optical module has a display and has a lens configured to present an image from the display to a corresponding eye box; 
 optical self-mixing sensors configured to measure the lenses of the optical modules, wherein each optical module has an array of the optical self-mixing sensors, wherein each lens has a lens surface, and wherein the array of optical self-mixing sensors in each optical module measures deformation of the lens surface in that optical module by measuring distances between the optical self-mixing sensors of the array and the lens surface; and 
 actuators, wherein each actuator is associated with a respective one of the optical modules and is configured to move the lens of that optical module relative to the display of that optical module based on the lens measurements. 
 
     
     
       13. The head-mounted device defined in  claim 12  wherein there are at least two of the optical self-mixing sensors for each of the lenses. 
     
     
       14. The head-mounted device defined in  claim 12  wherein each optical self-mixing sensor has a laser that emits light and has a detector and wherein the detectors of the optical self-mixing sensors are each configured to detect the emitted light from that optical self-mixing sensor after the emitted light has reflected from the lens surface.

Description:
This application claims the benefit of provisional patent application No. 63/028,458, filed May 21, 2020, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to electronic devices, and, more particularly, to electronic devices such as head-mounted devices having optical components. 
     BACKGROUND 
     Electronic devices such as head-mounted devices may have displays for displaying images and may have other optical components. 
     SUMMARY 
     A head-mounted device may have a head-mounted housing. Optical components may be supported by the head-mounted housing. The optical components may include cameras such as front-facing cameras and/or optical modules that have displays for displaying images to eye boxes. 
     Optical self-mixing sensors may be provided in the head-mounted device to detect changes in position between portions of the head-mounted device. These changes may include changes in the positions between optical module components such as lenses and displays. These changes may also involve movement of optical components such as cameras. 
     In response to detecting a change in optical component position using the optical self-mixing sensors (e.g., a change indicating that a component or other structure has moved from its desired position), actuators in the device may be adjusted to move the optical components or other action may be taken to compensate for the change. 
    
    
     
       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 diagram of an illustrative self-mixing sensor in accordance with an embodiment. 
         FIG.  5    contains graphs illustrating operation of the self-mixing sensor of  FIG.  4    in accordance with an embodiment. 
         FIG.  6    is a cross-sectional side view of an illustrative display system in accordance with an embodiment. 
         FIG.  7    is a cross-sectional side view of an illustrative camera system in accordance with an embodiment. 
         FIGS.  8 ,  9 ,  10 ,  11 ,  12 , and  13    are cross-sectional side views of illustrative optical systems with self-mixing sensors in accordance with embodiments. 
         FIG.  14    is a flow chart of illustrative operations associated with operating an electronic device with a self-mixing sensor in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device such as a head-mounted device may have optical components. The optical components may include optical modules that are used to provide images to a user&#39;s eyes. The head-mounted device may also have other optical components such as cameras. Components in a head-mounted device have the potential to experience misalignment if the device is subjected to stress during a drop event or other high stress event. To ensure that the device operates satisfactory, optical self-mixing sensors may be used to accurately measure the positions of components in the head-mounted device. Actuators may then move the optical components to compensate for any detected changes in position and/or other compensating action may be taken. 
     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., head-mounted 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 to help support device  10  on a user&#39;s head. A main support structure (e.g., a head-mounted housing such as main housing portion  12 M) of housing  12  may support electronic components such as displays  14 . 
     Main housing portion  12 M may include housing structures formed from metal, polymer, glass, ceramic, and/or other material. For example, housing portion  12 M may have housing walls on front face F and housing walls on adjacent top, bottom, left, and right side faces that are formed from rigid polymer or other rigid support structures and these rigid walls may optionally be covered with electrical components, fabric, leather, or other soft materials, etc. Housing portion  12 M may also have internal support structures such as a frame and/or structures that perform multiple functions such as controlling airflow and dissipating heat while providing structural support. The walls of housing portion  12 M may enclose internal components  38  in interior region  34  of device  10  and may separate interior region  34  from the environment surrounding device  10  (exterior region  36 ). Internal components  38  may include integrated circuits, actuators, batteries, sensors, and/or other circuits and structures for device  10 . 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. Configurations in which housing  12  forms goggles may sometimes be described herein as an example. 
     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. Portions of housing  12  (e.g., portions of main housing  12 M) on rear face R may form a cover such as cover  12 C. The presence of cover  12 C on rear face R may help hide internal housing structures, internal components  38 , and other structures in interior region  34  from view by a user. 
     Device  10  may have one or more cameras such as cameras  46  of  FIG.  1   . For example, forward-facing (front-facing) cameras may allow device  10  to monitor movement of the device  10  relative to the environment surrounding device  10  (e.g., the cameras may be used in forming a visual odometry system or part of a visual inertial odometry system). Forward-facing cameras may also be used to capture images of the environment that are displayed to a user of the device  10 . If desired, images from multiple forward-facing cameras may be merged with each other and/or forward-facing camera content can be merged with computer-generated content for a user. 
     Device  10  may have any suitable number of cameras  46 . For example, device  10  may have K cameras, where the value of K is at least one, at least two, at least four, at least six, at least eight, at least ten, at least 12, less than 20, less than 14, less than 12, less than ten, 4-10, or other suitable value. Cameras  46  may be sensitive at infrared wavelengths (e.g., cameras  46  may be infrared cameras), may be sensitive at visible wavelengths (e.g., cameras  46  may be visible cameras), and/or cameras  46  may be sensitive at other wavelengths. If desired, cameras  46  may be sensitive at both visible and infrared wavelengths. 
     Cameras  46  that are mounted on front face F and that face outwardly (towards the front of device  10  and away from the user) may sometimes be referred to herein as forward-facing or front-facing cameras. Cameras  46  may capture visual odometry information, image information that is processed to locate objects in the user&#39;s field of view (e.g., so that virtual content can be registered appropriately relative to real-world objects), image content that is displayed in real time for a user of device  10 , and/or other suitable image data. 
     Device  10  may have left and right optical modules  40 . Optical modules  40  support electrical and optical components such as light-emitting components and lenses and may therefore sometimes be referred to as optical assemblies, optical systems, optical component support structures, lens and display support structures, electrical component support structures, or housing structures. Each optical module may include a respective display  14 , lens  30 , and support structure such as support structure  32 . Support structure  32 , which may sometimes be referred to as a lens support structure, optical component support structure, optical module support structure, optical module portion, or lens barrel, may include hollow cylindrical structures with open ends or other supporting structures to house displays  14  and lenses  30 . Support structures  32  may, for example, include a left lens barrel that supports a left display  14  and left lens  30  and a right lens barrel that supports a right display  14  and right lens  30 . 
     Displays  14  may include arrays of pixels or other display devices to produce images. Displays  14  may, for example, include organic light-emitting diode pixels formed on substrates with thin-film circuitry and/or formed on semiconductor substrates, pixels formed from crystalline semiconductor dies, liquid crystal display pixels, scanning display devices, and/or other display devices for producing images. 
     Lenses  30  may include one or more lens elements for providing image light from displays  14  to respective eyes boxes  13 . Lenses may be implemented using refractive glass lens elements, using mirror lens structures (catadioptric lenses), using Fresnel lenses, using holographic lenses, and/or other lens systems. 
     When a user&#39;s eyes are located in eye boxes  13 , displays (display panels)  14  operate together to form a display for device  10  (e.g., the images provided by respective left and right optical modules  40  may be viewed by the user&#39;s eyes in eye boxes  13  so that a stereoscopic image is created for the user). The left image from the left optical module fuses with the right image from a right optical module while the display is viewed by the user. 
     It may be desirable to monitor the user&#39;s eyes while the user&#39;s eyes are located in eye boxes  13 . For example, it may be desirable to use a camera to capture images of the user&#39;s irises (or other portions of the user&#39;s eyes) for user authentication. It may also be desirable to monitor the direction of the user&#39;s gaze. Gaze tracking information may be used as a form of user input and/or may be used to determine where, within an image, image content resolution should be locally enhanced in a foveated imaging system. To ensure that device  10  can capture satisfactory eye images while a user&#39;s eyes are located in eye boxes  13 , each optical module  40  may be provided with a camera such as camera  42  and one or more light sources such as light-emitting diodes  44  or other light-emitting devices such as lasers, lamps, etc. Cameras  42  and light-emitting diodes  44  may operate at any suitable wavelengths (visible, infrared, and/or ultraviolet). As an example, diodes  44  may emit infrared light that is invisible (or nearly invisible) to the user. This allows eye monitoring operations to be performed continuously without interfering with the user&#39;s ability to view images on displays  14 . 
     Not all users have the same interpupillary distance IPD. To provide device  10  with the ability to adjust the interpupillary spacing between modules  40  along lateral dimension X and thereby adjust the spacing IPD between eye boxes  13  to accommodate different user interpupillary distances, device  10  may be provided with optical module positioning systems in housing  12 . The positioning systems may have guide members and actuators  43  that are used to position optical modules  40  with respect to each other. 
     Actuators  43  can be manually controlled and/or computer-controlled actuators (e.g., computer-controlled motors) for moving support structures (lens barrels)  32  relative to each other. Information on the locations of the user&#39;s eyes may be gathered using, for example, cameras  42 . The locations of eye boxes  13  can then be adjusted accordingly. 
     As shown in the rear view of device  10  of  FIG.  2   , cover  12 C may cover rear face R while leaving lenses  30  of optical modules  40  uncovered (e.g., cover  12 C may have openings that are aligned with and receive modules  40 ). As modules  40  are moved relative to each other along dimension X to accommodate different interpupillary distances for different users, modules  40  move relative to fixed housing structures such as the walls of main portion  12 M and move relative to each other. 
     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 user input information, sensor 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(s)  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(s)  14 . Display(s)  14  may include one or more display devices such as organic light-emitting diode display panels (panels with organic light-emitting diode pixels formed on polymer substrates or silicon substrates that contain pixel control circuitry), liquid crystal display panels, microelectromechanical systems displays (e.g., two-dimensional mirror arrays or scanning mirror display devices), display panels having pixel arrays formed from crystalline semiconductor light-emitting diode dies (sometimes referred to as microLEDs), and/or other display devices. 
     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 such as a touch sensor that forms a button, trackpad, or other input device), 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 (e.g., cameras), 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, three-dimensional camera systems such as depth sensors (e.g., structured light sensors and/or depth sensors based on stereo imaging devices that capture three-dimensional images) and/or optical sensors such as self-mixing sensors and light detection and ranging (lidar) sensors that gather time-of-flight measurements (e.g., time-of-flight cameras), humidity sensors, moisture sensors, gaze tracking sensors, electromyography sensors to sense muscle activation, facial sensors, interferometric sensors, time-of-flight sensors, magnetic sensors, resistive sensors, distance sensors, angle 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 (e.g., voice commands), 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. 
     It is desirable for optical components in device  10  to remain in satisfactory alignment during operation of device  10 . Due to a drop event or other event imparting stress on device  10 , there is a risk that the positions of displays, lenses, cameras, other optical components, and/or other structures in device  10  will move relative to their initial positions. To ensure that device  10  operates satisfactorily, even if subjected to large amounts of stress, device  10  may use sensors to measure component positions. In response to measuring a change in component position, device  10  (e.g., control circuitry  20 ) can take compensating action (e.g., by using an actuator to adjust the position of the component to ensure that the component is positioned satisfactorily, by warping image data associated with a camera or display to compensate, etc.). In an illustrative configuration, which may sometimes be described herein as an example, one or more actuators may be used to reposition a moved optical component so that the optical component remains in its desired position even when device  10  is subjected to drop events and other high stress events. Configurations in which actuators use measured position information while moving lenses, displays, and/or other components to adjust focus and/or otherwise adjust the operation of the optical components may also be described herein as examples. 
     It may be desirable to measure relatively small changes in component position, so that components can be maintained in desired positions. For example, it may be desirable to maintain the position of a lens or other component in its original position within a tolerance of less than 30 microns, less than 20 microns, less than 7 microns, or less than 3 microns (as examples). In maintaining tight tolerances for the optical components in device  10 , it may be desirable to take correspondingly accurate position measurements. In an illustrative configuration, which is described herein as an example, optical position sensors such as optical self-mixing sensors are used to measure component positions within these tight tolerances (e.g., with an accuracy of better than 10 microns, better than 2 microns, or better than 1 micron, or other suitable accuracy). Submicron position measurement accuracy or other satisfactory measurement precision allows lenses, displays, cameras, and/or other optical components to be placed in desired locations without introducing significant misalignment errors. 
     An illustrative optical self-mixing sensor is shown in  FIG.  4   . Self-mixing sensor  70 , which may sometimes be referred to as an optical self-mixing position sensor or self-mixing orientation sensor may be used to measure distance and therefore determine the relative position between the sensor and a target structure. In some configurations, angular orientation may be measured using one or more self-mixing sensors. For example, angular tilt may be measured by measuring two or more distances. Tilt about one axis may, as an example, be measured using a pair of distance measurements made at different respective locations on a component, whereas tilt about two axes may be measured using three such distance measurements. Arrangements in which self-mixing sensors are referred to as measuring distance, displacement, or position may sometimes be described herein as an example. In general, position, angular orientation, changes in position and/or orientation, and/or other self-mixing sensor measurements may be directly gathered and/or may be derived from the measurements of distance from self-mixing sensors. 
     In the example of  FIG.  4   , self-mixing sensor  70  is being used to measure the separation (distance D) between sensor  70  and target  82 . Target structures in device  10  such as target  82  of  FIG.  4    may be portions of lenses (e.g., lenses  30  of  FIG.  1   ), portions of support structures (e.g., a lens barrel or other support structure  32  for a lens and/or other optical module components), display structures (e.g., displays  14 ), portions of cameras (e.g., cameras  46  and/or cameras  42 ), and/or other structures in device  10  (e.g., housing structures in portion  12 M). Self-mixing sensors such as sensor  70  may be mounted on or adjacent to housing structures (e.g., a structure in portion  12 M) and/or sensor  70  may be mounted on or adjacent to lenses (e.g., lenses  30  of  FIG.  1   ), portions of support structures (e.g., lens barrel  32 ), display structures (e.g., displays  14 ), portions of cameras, and/or other structures in device  10  (e.g., housing structures in portion  12 M). In this way, distance D may correspond to a display-to-lens measurement or housing-to-lens measurement that reveals information on lens alignment and/or may otherwise be used in measuring distances between lenses, cameras, displays, housing structures, etc. In the event that measurements with one or more sensors  70  reveal that a component is misaligned relative to its desired position, compensating action may be taken. For example, control circuitry  20  may use an actuator to move a lens, display, camera, or other component in device  10  to compensate for measured changes in component position. If, as an example, lens  30  is 30 microns too far from display  14 , lens  30  may be moved towards display  14  by 30 microns. 
     As shown in the illustrative configuration of  FIG.  4   , self-mixing sensor  74  may include a laser such as vertical cavity surface emitting laser  80  (e.g., self-mixing proximity sensor  70  may be a coherent self-mixing sensor having a diode laser or other coherent or partially coherent source of light or other electromagnetic radiation). Laser  80  may have thin-film interference filter mirrors  74  (sometimes referred to as Bragg reflectors) each of which is formed from a stack of thin-film layers of alternating index of refraction. Active region  76  may be formed between mirrors  74 . The lower mirror in laser  80  may have a nominal reflectivity of less than 100% to allow some of the light of laser  80  to reach overlapped photodiode  72  or, in configurations in which photodiode  72  is located elsewhere in sensor  70  (e.g., laterally adjacent to laser  80 ), the lower mirror may have a nominal reflectivity of 100%. The upper mirror in laser  80  may have a slightly lower reflectivity, so that laser  80  emits light  84  towards target  82 . Laser  80  may be controlled by applying a drive signal to terminals  86  using control circuitry  20  (e.g., a drive circuit in circuitry  20 ). Sensing circuitry (e.g., photodiode  72  and/or associated sensing circuitry in circuitry  20 ) can measure the light output of laser  80  (as an example). 
     Emitted light  46  may have an infrared wavelength of 850-1200 nm, 800 nm to 1100 nm, 920-960 nm, at least 800 nm, at least 900 nm, at least 1000 nm, less than 1200 nm, less than 1100 nm, less than 1000 nm, or less than 900 nm, or other suitable wavelength (e.g., a visible wavelength, an ultraviolet wavelength, an infrared wavelength, a near-infrared wavelength, etc.). When emitted light  84  illuminates target  82 , some of emitted light  84  will be reflected backwards towards sensor  70  as reflected light  86  (e.g., light that is specularly reflected from target  82  and/or that is backscattered from a matte surface in target  82 ). 
     Sensor  70  of  FIG.  4    includes a light sensitive element (e.g., a light detector such as photodiode  72 ). Photodiode  72  in the example of  FIG.  4    is located under laser  80 , but configurations in which photodiode  72  is adjacent to laser  80 , is located on a separate substrate than laser  80 , is located above active area  76 , and/or has other configurations may be used, if desired. The terminals of photodiode  72  may be coupled to sensing circuitry in control circuitry  20 . This circuitry gathers photodiode output signals that are produced in response to reception of reflected light (specularly reflected and/or backscattered portions of emitted light  84 ) such as reflected light  86 . In addition to using a photodiode, self mixing can be detected using laser junction voltage measurements (e.g., if the laser is driven at a constant bias current) or laser bias current (e.g., if the laser is driven at a constant voltage). 
     Target  82  is located at a distance D from proximity sensor  70 . Some of light  84  that is reflected or backscattered from target  82  as reflected light  86  reenters the laser cavity of laser  80  (i.e., this fed back light mixes with the light in the laser cavity), perturbing the electric field coherently and causing a perturbation to the carrier density in laser  80 . These perturbations in laser  80  cause coherent self-mixing fluctuations in the power of emitted light  84  and associated operating characteristics of laser  80  such as laser junction voltage and/or laser bias current. These fluctuations may be monitored. For example, the fluctuations in the power of light  86  may be monitored using photodiode  72 . In the example of  FIG.  4   , photodiode  72  is an integrated monolithic photodiode that is formed under laser  80 , but other configurations may be used, if desired. 
     Control circuitry  20  is configured to supply drive current for laser  80  and includes circuitry for sensing the response of photodiode  72 . Sensed photodiode output may include measurements of diode current and/or voltage. A modulation scheme may be used for driving laser  80  for the purpose of inducing a wavelength modulation and a photodiode output processing scheme (using measurements of photodiode current, junction voltage, bias current, etc.) may be used in processing the measured self-mixing fluctuations in output power to allow control circuitry  20  to determine the distance D between sensor  70  and target  82  in accordance with the principles of self-mixing interferometry. 
     A modulation scheme for driving laser  80  may, for example, use a triangular wave drive signal that, due to the dependence of output wavelength on drive current magnitude of laser  80 , continuously varies the wavelength of light  84  between a first wavelength WL 1  and a second wavelength WL 2  during each half-period of the triangular wave. The wavelength variations of light  84  cause the self-mixing interference signal of laser  80  to exhibit ripples. If desired, other modulation schemes may be used for driving laser  80  (e.g., sinusoidal driving schemes, etc.). 
     The processing scheme used on the photodiode signal uses a frequency extraction transform to extract the period of the ripples, from which distance D may be calculated. Distance D may, for example, be determined with an accuracy of better than 50 microns, better than 20 microns, better than 10 microns, better than 5 microns, better than 2 microns, better than 1 micron, or other suitable accuracy. Due to this high accuracy, measurements of where a lens or other optical component is located within device  10  can be determined with sufficient precision to allow actuators to move the lens and/or other optical component to compensate for undesired drop-induced movement or to take other suitable compensating action. The frequency extraction transform can have a temporal resolution (e.g., wavelet transform) or not (e.g., Fourier transform). 
     An illustrative signal processing approach for sensor  70  shown in  FIG.  5   . 
     The first (uppermost) trace of  FIG.  5    shows how laser drive current Id for laser  80  may be modulated using an alternating-current (AC) signal such as a triangle wave. This modulates the temperature of laser  80  and therefore the output wavelength of light  84 . For example, the wavelength of light  84  may vary between a first value WL 1  (when drive signal Id is at a minimum) and wavelength WL 2  (when drive signal Id is at a maximum). In accordance with the principles of self-mixing interferometry, the modulation of the wavelength of light  84  allows the self-mixing proximity sensor to measure target distance D without varying distance D. 
     The second (second to uppermost) trace of  FIG.  5    shows how the resulting output signal PDout from photodiode  72  contains self-mixing interference ripples  60 . In configurations in which laser current or laser voltage are measured, the self-mixing interference ripples will appear in the measured current or voltage. 
     Control circuitry  20  (e.g., a sense circuit based on an operational amplifier circuit or other sensing circuitry) may be configured to differentiate signal PDout (or the measured current or voltage of laser  80 ). As a result, control circuitry  20  (e.g., the sense circuit of circuitry  20 ) may produce an output signal Vsig, as shown in the third (third from uppermost) trace of  FIG.  5   . The signal Vsig is ideally a square wave onto which ripples  60  are imposed. To facilitate subsequent signal processing (e.g., processing to perform a frequency extraction transform), the mean of signal Vsig during high periods  64  may be subtracted from signal Vsig during high periods  64  (digitally or using analog circuitry in control circuitry  20 ), thereby equalizing the direct-current (DC) component in periods  62  and  64 , as shown by signal V in the fourth (lowermost) trace of  FIG.  5   . 
     A frequency-extraction transform such as a fast Fourier transform (FFT) or other frequency-extraction transform (e.g., a Hilbert transform, a continuous or discrete wavelet transform, a multiple signal classification method, etc.) may be applied to signal V to determine the frequency of ripples  60 . With one illustrative approach, the ripple frequency can be determined by identifying the frequency associated with a peak in the FFT amplitude curve. Frequencies with lower peaks in the FFT output can be assumed to be associated with noise and can be ignored. A more accurate frequency assessment can be made by fitting a curve to the peaks in the curve (e.g., processing the output amplitude of the FFT algorithm at each of the output frequencies of the FFT algorithm to identify the ripple frequency). For example, a curve such as a Gaussian curve may be fit to the frequency peaks of the output of the FFT process to accurately identify a ripple frequency fp. The frequency fp may then be used in calculating target distance D. In some illustrative configurations, other types of demodulation may be used to determine distance D. For example, IQ demodulation may be used in scenarios in which laser  80  is modulated sinusoidally. If desired, a separate phase modulator (e.g., a separate electro-optic modulator such as a lithium niobite electro-optic modulator) may be used in modulating light  84 . These self-mixing modulation and signal processing arrangements and/or other arrangements may allow distances such as distance D to be measured in device  10  so that this distance information may be used in adjusting components in device  10 . 
     Accurate distance measurements of the type that may be produced using sensor  70  may be used in providing real-time feedback on optical component positions within device  10 . For example, the positions of lenses, displays, image sensors, and/or other optical components and/or the housing structures used in supporting such components may be measured using sensors such as sensor  70 , so that control circuitry  20  can adjust actuators to reposition such as components and/or can take other appropriate action. 
     Consider, as an example, the arrangement of  FIG.  6   . In the example of  FIG.  6   , multiple sensors  70  are being used to measure the position of lens  30  relative to display  14  (e.g., a pixel array) in optical module  40 . A first sensor  70  may measure distance D 1  between display  14  and lens  30  (e.g., along a right-hand edge of lens  30 ) and a second sensor  70  may measure distance D 2  between display  14  and lens  30  (e.g., along a left-hand edge of lens  30 ). A third sensor  70  may, if desired, measure the separation between lens  30  and display  14  (e.g. so that the angular orientation of lens  30  in all dimensions may be determined). 
     By using sensors  70 , the separation of lens  30  from display  14  and the orientation of lens  30  relative to display  14  may be measured. Using this type of arrangement, undesired movement of lens  30  relative to display  14 , undesired movement of lens  30  relative to a housing chassis or other structural members in housing portion  12 M, undesired movement of display  14  relative to lens  30  and/or housing portion  12 M, and/or other undesired movements of portions of optical module  40  in device  10  may be detected. 
     If desired, sensors  70  may also be used to actively monitor the position of lens  30  during lens position adjustments that are being made to vary the distances of virtual images as the user is viewing content on display  14  from eye box  13 . Such lens position adjustments may be made, for example, to adjust the focus of module  40  and thereby adjust the amount of accommodation needed by a user to view the image on display  14 . Control circuitry  20  may, as an example, adjust lens focus to minimize or eliminate vergence-accommodation mismatch as three-dimensional content associated with the left and right images on left and right optical modules  40  is being presented to the user. 
     In the illustrative configuration of  FIG.  7   , sensors  70  are being used to monitor the relative position between camera lens  30 ′ in a camera (camera  46  in the example of  FIG.  7   ) and camera image sensor  461  while camera  46  is capturing an image of real-world object  90 . A first sensor  70  may, for example, measure distance D 1  while a second sensor measure distance D 2 . Additional sensors(s)  70  may be used, if desired. In this way, the position of lens  30 ′, image sensor  461 , and/or associated housing structures may be measured during operation of device  10  so that appropriate action may be taken (e.g., compensating movements of lens  30 ′, image sensor  461 , etc.). 
       FIG.  8    is a cross-sectional side view of a portion of an illustrative optical module with sensors  70 . In the example of  FIG.  8   , optical module  40  includes lens  30  (e.g., a catadioptric lens or other lens) and display  14  (e.g., a display with an array of organic light-emitting diodes). Lens  30  may be supported in optical module support structure  32  (e.g., a lens barrel). Self-mixing sensors  70  and display  14  may be supported by support structures  92  and  94 , respectively. Display  14  and support structure  94  may be coupled to support structure  32  (e.g., structure  94  may be part of a lens barrel structure) or, as shown in  FIG.  8   , structure  94  may be a structure that is separate from support structure  32  (e.g., a support structure in housing portion  12 M, a display substrate for a display panel associated with display  14 ) and that is optionally coupled to support structure  32 . 
     During operation, control circuitry  20  may measure the position of lens  30  using sensors  70 . For example, sensors  70  may be mounted directly to a support structure such as support structure  92  of  FIG.  8    (e.g. a chassis or other housing structure in housing portion  12 M) that is separate from support structure  32  of optical module  40  and which therefore serves to establish a fixed reference frame from which the position of lens  30  may be measured. In arrangements in which display  14  and support  94  are attached to support  92 , the sensing arrangement of  FIG.  8    may allow sensors  70  to measure the relative position between lens  30  and display  14 . 
     In response to the information on the position of lens  30  gathered by sensor(s)  70 , control circuitry  20  can adjust the position of lens  30  (e.g., the position of lens  30  relative to support structure  92  and display  14 ) using actuators  96 . Actuators  96  may, if desired, be mounted between support structure  92  (which serves as the fixed reference frame) and lens  30 . Actuators  96  may be piezoelectric actuators, electromagnetic actuators (e.g., motors), and/or other computer-controlled positioners. Two or more, three or more, or other suitable number of actuators  96  may be used to position lens  30 . For example, three actuators  96  spaced 120° apart from each other around the perimeter of lens  30  may be used to adjust the orientation of lens  30 . Actuators  96  may adjust the separation along axis Z between display  14  and lens  30  and/or may be configured to shift lens  30  laterally (e.g., along dimensions X and/or Y). 
     Adhesive may be used in mounting lens  30  to support structure  32 . In this type of arrangement, there may be a potential for glue shrinkage to affect the relative position between lens  30  and support structure  32 . This can affect the measurement of the position of lens  30 , because the arrangement of  FIG.  8    involves indirect lens position measurements (measurements in which lens position is determined by measuring lens barrel position and inferring lens position from measured lens barrel position), rather than direct lens position measurements. 
     If desired, the position of lens  30  may be measured directly (rather than indirectly through support structure  32  as shown in  FIG.  8   ).  FIG.  9    is a cross-sectional side view of an illustrative optical module in which the position of lens  30  relative to structure  92  is measured directly (e.g., because light  84  reflects directly from the inwardly facing surface of lens  30 ). 
     Other directly lens position sensing arrangements may be used, if desired. In the example of  FIG.  10   , there are multiple sensors  70  (e.g., one or more sets of three sensors  70 - 1 ,  70 - 2 , and  70 - 3 ) for measuring displacement in different directions. In this illustrative configuration, each sensor  70 - 1  may emit light  84  that propagates on the X-Z plane and therefore measures lens position along this first direction, each sensor  70 - 2  may emit light  84  that propagates on the Y-Z plane and therefore measures lens position along this second direction that is different than the first direction, and each sensor  70 - 3  may emit light  84  that propagates in the Z direction (e.g. a direction that is different than the first and second directions). With this configuration, sensors  70 - 1  and  70 - 2  can detect lateral motion of lens  30  (e.g., motion along the X and Y axes of  FIG.  10   ). Each sensor  70 - 3  measures distance along only the Z dimension (in this example), thereby decoupling these Z-axis measurements from the lateral position measurements made using sensors  70 - 1  and  70 - 2 . 
     In the example of  FIG.  11   , an array of self-mixing sensors  70  (e.g., a dense array of at least 10, at least 100, fewer than 1000, fewer than 50, or other suitable number) has been provided in device  10 . Sensors  70  may face the inwardly-facing surface of lens  30  (e.g., lens surface  98 ). During operation, sensors  70  can sense the position of surface  98  and thereby measure deformations to the shape of surface  98 . This information may be used dynamically by control circuitry  20  (e.g., to adjust lens  30  by deforming the shape of surface  98  and/or by moving lens  30 , to adjust display  14 , and/or to adjust other structures in device  10  using actuators, to adjust image data such as by warping displayed images on display  14  to counteract lens distortion, etc.). If desired, the array of sensors  70  of  FIG.  11    may be located behind display  14  (e.g., display  14  may be partially transparent so that light from sensors  70  can pass through display  14 ). 
     Another illustrative arrangement is shown in  FIG.  12   . As shown in the configuration of  FIG.  12   , one or more sensors  70  may be mounted on support structure  94  (e.g. a housing support structure, display panel substrate for display  14 , and/or other structure forming part of display  14  and/or directly attached to and/or supporting display  14 ). 
       FIG.  13    shows how lens  30  may be provided with a planar surface such as surface  98 P or other surface that deviates from inner optical surface  98  of lens  30 . Planar surface  98 P may help enhance optical feedback to sensor  70  by increasing the amount of emitted light from sensor  70  that is reflected from the surface of lens  30  towards sensor  70 . In the absence of a surface such as surface  98 P that is oriented to reflect light  84  back to sensor  70 , light  84  may tend to reflect in a direction that is not as well aligned with sensor  70 . 
     Sensors  70  can be used to measure the positions of lenses  30  in optical modules  40  and/or other lenses (e.g., camera lenses). For example, one or more sensors  70  may be used to measure the position of a left lens in a left optical module and one or more sensors  70  may be used to measure the position of a right lens in a right optical module. Control circuitry  20  can measure lens position separately for left and right optical modules  40  and can adjust lens position separately for the left and right optical modules using individually adjustable actuators  96 . The ability to control left and right lens-to-display separation separately can assist users with vision defects such as users with different optical powers (eye glass prescriptions) for their left and right eyes, thereby reducing or eliminating the need for providing modules  40  with user-specific corrective lenses. 
     If desired, actuators  96  may be used to shake (e.g., vibrate) lenses (e.g., lenses  30 ) to dislodge dust and/or other debris from the surfaces of the lenses. This actuator-based cleaning arrangement may be particularly helpful in cleaning inwardly facing lens surfaces such as surface  98  of lens  30 , because these surface may not be easily accessed by the user. Vibrations to clean lenses such as lenses  30  in optical modules  40  may be applied to the lenses each time device  10  is powered up and/or at other suitable times. 
     Illustrative operations associated with using device  10  are shown in  FIG.  14   . 
     At suitable times (e.g. upon power up, in response to detection of a drop event with an inertial measurement unit and/or other sensor in device  10 , in response to a user command, according to a schedule, etc.) measurements of position may be made by control circuitry  20  (block  110 ). 
     During the operations of block  110 , sensors  70  may measure distances D between sensors  70  and adjacent structures in device  10 . Distances D may correspond to distances between sensors  70  and structures such as the lens surfaces and/or lens barrels for lenses  30 , displays  14  (e.g., display substrates and/or other display structures), cameras, support structures in device  10  for supporting portions of optical modules  40  such as lenses  30  and/or displays  14 , support structures in device  10  for supporting other optical components, and/or other structures. Sensors  70  may be coupled to lenses  30 , displays  14 , lens barrels (support structures  32 ), display support structures, housing structures such as structures for supporting cameras, cameras, and/or other structures in device  10 . In this way, information on the relative and/or absolute positions of these structures and therefore associated information on the translational and/or angular alignment and orientation of these structures may be gathered (e.g., information on misalignment of these structures relative to their desired alignment such as information on lens alignment, display alignment, optical module alignment, lens surface shape, camera alignment, housing structure alignment, and/or other information on how structures in device  10  may be misaligned relative to their desired positions). In systems with variable focus (e.g., systems in which the distance between lenses  30  and displays  14  in optical modules  40  is adjusted to adjust focus to place computer-generated content on displays  14  at various different virtual image distances to help reduce vergence-accommodation mismatch), information can be gathered by sensors  70  on misalignment resulting from deviations between the positions of lenses  30  and their desired adjusted locations). 
     During the operations of block  112 , control circuitry  20  may adjust adjustable components in device  10  based on the measurements from sensors  70 . For example, actuators in device  10  may be adjusted to reposition lenses  30 , displays  14 , optical modules  40 , support structures  32 , cameras  46 , support structures in housing portion  14 M, and/or other structures in device  10 . In this way, detected misalignment in the position of a component (e.g., misalignment of lenses, displays, support structures, portions of lenses leading to lens deformation, image sensors, camera lenses, other portions of cameras  46 , and/or other components and/or structures in device  10  relative to each other) can be corrected. In an illustrative configuration, in response to detecting that lens  30  is not currently in its desired position, actuators  96  may move lens to the desired position (e.g., lens  30  may be moved laterally in dimensions X and/or Y, vertically in dimension Z, angularly by tilting about X, Y, and/or Z axes, etc.). If desired, the shape of lens  30  may be changed using actuators (e.g., by applying force that deforms lens  30 ). This allows an undesired lens shape to be corrected. 
     In addition to or instead of moving or otherwise physically adjusting all or some of the components in optical modules  40 , cameras in device  10 , and/or other optical components and/or housing structures in device  10  in response to the data gathered using self-mixing sensors  70 , control circuitry  20  may make adjustments to image data and/or other data handled by device  10 . For example, if measurements from sensors  70  indicate that display  14  has shifted to the left from its desired position, control circuitry  20  can warp (shift, rotate, and/or shear) the data for the image being displayed by display  14  to shift the image back to the right by a corresponding amount. In this way, detected optical component misalignments can be corrected digitally (e.g., by processing captured image data from cameras  46  and/or by processing image data being supplied to displays  14  to adjust images for measured misalignment). 
     As indicated by line  114 , the operations of blocks  110  and  112  may be performed continuously (e.g., according to a schedule, in response to detected drop events, in response to user input, etc.). In this way, optical components in device  10  may be maintained in satisfactory alignment, even if the positions of these devices is affected by drop events or other high-stress conditions. 
     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: 20210414
Publication Date: 20230808
Grant Date: 20230808
Priority Date: 20200521
Inventors: Mutlu, Mehmet
ISIKMAN, SERHAN O.
GRANGER, ZACHARY A.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01B9/02092", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B17/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/017", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B27/0172", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B27/0176", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0163", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/0161", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B27/0176", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01B9/02092", "inventive": true, "first": false, "tree": "[]"}, {"code": "G03B17/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0163", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/0161", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01B9/02092", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B2027/0138", "inventive": false, "first": false, "tree": "[]"}, {"code": "G03B17/12", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 76197660