Head-mounted electronic device with alignment sensors

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 movable optical modules that have displays for displaying images to eye boxes. Sensors may be provided in the head-mounted device to detect changes in orientation between respective optical modules, between respective portions of a chassis, display cover layer, or other head-mounted support structure in the housing, between optical components such as cameras, and/or between optical components and housing structures. Information from these sensors can be used to measure image misalignment such as image misalignment associated with misaligned cameras or misalignment between optical module images and corresponding eye boxes.

FIELD

This relates generally to electronic devices, and, more particularly, to electronic devices such as head-mounted devices.

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.

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 modules, between portions of a chassis, display cover layer, or other head-mounted support structure, between optical components such as cameras, and/or between optical components and housing structures. Information from these sensors can be used to measure image misalignment such as image misalignment associated with misaligned cameras or image misalignment between optical module images and the eye boxes to which these images are being provided. During operation of the head-mounted device, images can be warped to compensate for measured misalignment.

DETAILED DESCRIPTION

An electronic device such as a head-mounted device may have a front face that faces away from a user's head and may have an opposing rear face that faces the user's head. Optical modules may be used to provide images to a user's eyes. The positions of the optical modules may be adjusted to accommodate different user interpupillary distances. The head-mounted device may have actuators and optical module guide structures to allow the optical module positions to be adjusted. The head-mounted device may also have other optical components such as front-facing cameras.

A top view of an illustrative head-mounted device is shown inFIG.1. As shown inFIG.1, head-mounted devices such as electronic device10may have head-mounted support structures such as housing12. Housing12may include portions (e.g., head-mounted support structures12T) to allow device10to be worn on a user's head. Support structures12T may be formed from fabric, polymer, metal, and/or other material. Support structures12T may form a strap or other head-mounted support structures to help support device10on a user's head. A main support structure (e.g., a head-mounted housing such as main housing portion12M) of housing12may support electronic components such as displays14.

Main housing portion12M may include housing structures formed from metal, polymer, glass, ceramic, and/or other material. For example, housing portion12M 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 portion12M 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 portion12M may enclose internal components38in interior region34of device10and may separate interior region34from the environment surrounding device10(exterior region36). Internal components38may include integrated circuits, actuators, batteries, sensors, and/or other circuits and structures for device10. Housing12may 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 housing12forms goggles may sometimes be described herein as an example.

Front face F of housing12may face outwardly away from a user's head and face. Opposing rear face R of housing12may face the user. Portions of housing12(e.g., portions of main housing12M) on rear face R may form a cover such as cover12C. The presence of cover12C on rear face R may help hide internal housing structures, internal components38, and other structures in interior region34from view by a user.

Device10may have one or more cameras such as cameras46ofFIG.1. For example, forward-facing (front-facing) cameras may allow device10to monitor movement of the device10relative to the environment surrounding device10(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 device10. 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.

Device10may have any suitable number of cameras46. For example, device10may 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. Cameras46may be sensitive at infrared wavelengths (e.g., cameras46may be infrared cameras), may be sensitive at visible wavelengths (e.g., cameras46may be visible cameras), and/or cameras46may be sensitive at other wavelengths. If desired, cameras46may be sensitive at both visible and infrared wavelengths.

Cameras46that are mounted on front face F and that face outwardly (towards the front of device10and away from the user) may sometimes be referred to herein as forward-facing or front-facing cameras. Cameras46may capture visual odometry information, image information that is processed to locate objects in the user'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 device10, and/or other suitable image data.

Device10may have left and right optical modules40. Optical modules40support 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 display14, lens30, and support structure such as support structure32. Support structure32, 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 displays14and lenses30. Support structures32may, for example, include a left lens barrel that supports a left display14and left lens30and a right lens barrel that supports a right display14and right lens30.

Displays14may include arrays of pixels or other display devices to produce images. Displays14may, 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.

Lenses30may include one or more lens elements for providing image light from displays14to respective eyes boxes13. 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's eyes are located in eye boxes13, displays (display panels)14operate together to form a display for device10(e.g., the images provided by respective left and right optical modules40may be viewed by the user's eyes in eye boxes13so 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's eyes while the user's eyes are located in eye boxes13. For example, it may be desirable to use a camera to capture images of the user's irises (or other portions of the user's eyes) for user authentication. It may also be desirable to monitor the direction of the user'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 device10can capture satisfactory eye images while a user's eyes are located in eye boxes13, each optical module40may be provided with a camera such as camera42and one or more light sources such as light-emitting diodes44or other light-emitting devices such as lasers, lamps, etc. Cameras42and light-emitting diodes44may operate at any suitable wavelengths (visible, infrared, and/or ultraviolet). As an example, diodes44may 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's ability to view images on displays14.

Not all users have the same interpupillary distance IPD. To provide device10with the ability to adjust the interpupillary spacing between modules40along lateral dimension X and thereby adjust the spacing IPD between eye boxes13to accommodate different user interpupillary distances, device10may be provided with optical module positioning systems in housing12. The positioning systems may have guide members and actuators43that are used to position optical modules40with respect to each other.

Actuators43can be manually controlled and/or computer-controlled actuators (e.g., computer-controlled motors) for moving support structures (lens barrels)32relative to each other. Information on the locations of the user's eyes may be gathered using, for example, cameras42. The locations of eye boxes13can then be adjusted accordingly.

As shown in the rear view of device10ofFIG.2, cover12C may cover rear face R while leaving lenses30of optical modules40uncovered (e.g., cover12C may have openings that are aligned with and receive modules40). As modules40are moved relative to each other along dimension X to accommodate different interpupillary distances for different users, modules40move relative to fixed housing structures such as the walls of main portion12M 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 inFIG.3. Device10ofFIG.3may be operated as a stand-alone device and/or the resources of device10may be used to communicate with external electronic equipment. As an example, communications circuitry in device10may 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 device10ofFIG.3.

As shown inFIG.3, a head-mounted device such as device10may include control circuitry20. Control circuitry20may include storage and processing circuitry for supporting the operation of device10. 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 circuitry20may 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 circuitry20may use display(s)14and other output devices in providing a user with visual output and other output.

To support communications between device10and external equipment, control circuitry20may communicate using communications circuitry22. Circuitry22may include antennas, radio-frequency transceiver circuitry, and other wireless communications circuitry and/or wired communications circuitry. Circuitry22, which may sometimes be referred to as control circuitry and/or control and communications circuitry, may support bidirectional wireless communications between device10and 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, circuitry22may 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. Device10may, 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, device10may include a coil and rectifier to receive wireless power that is provided to circuitry in device10.

Device10may include input-output devices such as devices24. Input-output devices24may be used in gathering user input, in gathering information on the environment surrounding the user, and/or in providing a user with output. Devices24may include one or more displays such as display(s)14. Display(s)14may 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.

Sensors16in input-output devices24may 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, sensors16may 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, device10may use sensors16and/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 device10may include additional components (see, e.g., other devices18in input-output devices24). 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. Device10may 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 device10to remain in satisfactory alignment during operation of device10. Consider, as an example, optical modules40and front facing cameras46. Due to a drop event or other event imparting stress on housing portion12M, housing portion12M and the components of housing portion12M may become deformed and misaligned. For example, the left and right optical modules40in device10may become misaligned and/or a pair of front-facing cameras46may become misaligned. This can adversely affect device performance. For example, if the left and right images being viewed by a user become misaligned with respect to each other, these images may not fuse satisfactorily in the user's vision and/or a user may experience discomfort during image viewing. Similarly, misalignment of cameras46can lead to undesired misalignment between captured images.

To ensure that device10is comfortable to wear on a user's head, device10should not be too heavy or too large. Particularly when using lightweight and compact structures to form device10, however, there is a risk that excessive stress on the structures of device10will adversely affect the alignment of optical components of device10. To accommodate potential optical component misalignment, device10may be provided with sensors that can measure misalignment.

Consider, as an example, head-mounted device10ofFIG.4. In the configuration ofFIG.4, device10has been provided with sensor16(e.g., a strain gauge or other sensor). Sensor16may, as an example, be coupled to a portion of housing12M. During operation, sensor16can detect when housing12M has become deformed (e.g., bent) due to a drop event or other stress. As shown inFIG.4, optical modules40provide left and right images to corresponding left and right eye boxes30in directions50and left and right forward-facing cameras46capture corresponding left and right camera images. When housing12M ofFIG.4is not deformed as shown inFIG.4, the images provided by optical modules40in directions50are aligned with eye boxes30, so images for the left and right eyes fuse properly into a single image when viewed by the user's left and right eyes. Cameras46are also aligned satisfactorily.

When housing12M is deformed as shown inFIG.5, however, the images provided in directions50are no longer aligned with eye boxes30and/or the images captured by cameras46are no longer aligned satisfactorily. Due to the presence of sensors such as sensor16, image misalignment associated with display images and/or camera images can be detected in real time and appropriate compensating action taken. As an example, if it is determined that an image from a given optical module40is rotated with respect to a corresponding eye box30, device10(e.g., control circuitry in device10such as control circuitry20ofFIG.3) may apply a corresponding image warping process with a corresponding counterrotation to the image being produced by that optical module. This ensures that the images from optical modules40are properly aligned with eye boxes30and each other, even if optical modules have become physically misaligned. Similarly, images captured by forward facing cameras46may be processed to compensate for detected misalignment between the cameras. Configurations where misalignment between cameras and optical modules and/or other optical component misalignment is detected and compensated may also be used.

One or more sensors may be provided to gather information on the positions of structures in device10. These sensors can produce output that is used in detecting misalignment and may therefore sometimes be referred to as misalignment sensors, position sensors, and/or orientation sensors. The sensors may be strain gauges, optical sensors, radio-frequency sensors, acoustic sensors, magnetic sensors, and/or other sensors that detect deformation of housing12M and/or other portions of device10leading to misalignment of optical components with respect to each other and/or to housing12.

Using a misalignment sensor, the orientation of housing12M and/or one or more optical components in housing12M such as optical modules40and/or cameras46can be measured. Control circuitry20can process the output from one or more orientation sensors in real time and can take suitable action to compensate for the effects of optical component misalignment. As an example, control circuitry20can warp or otherwise modify image data (e.g., display output data associated with one or more optical module displays, captured camera images from one or more cameras, etc.) to digitally compensate for misalignment. During image warping, an image is geometrically distorted (e.g., a geometrical image transform is applied to the image such as a shift, shear, rotation, etc.). In this way, device10can be operated satisfactorily, even if optical components in device10have become misaligned.

Illustrative misalignment sensor configurations are shown inFIGS.6-20.

In the example ofFIG.6, misalignment sensor16has a first portion16-1and a second portion16-2. Shaft16-2′ of portion16-2moves in and out of portion16-1as the distance D between portions16-1and16-2varies. Sensor16may be, for example, a resistance-based sensor (e.g., a potentiometer) that is characterized by a resistance R between its terminals52that is proportional to distance D. Resistance-based sensors and other misalignment sensors16may be configured to measure changes in displacement (e.g., distance D) and/or changes in angular orientation that are indicative of component movement and/or housing deformation and that are therefore indicative of associated image misalignment.

In the example ofFIG.7, sensor16has an emitter54and a detector56for detecting misalignment between structures in device10such as structure64and structure62. Emitter54may emit signals58(e.g., light, radio-frequency signals, acoustic signals such as ultrasonic signals, etc.). Emitted signals58reflect from a reflective surface of structure in device10such as structure62(e.g., a portion of an optical module, a housing structure, a portion of a camera, etc.). Emitted signals58that have reflected from structure62such as reflected signals60are detected by detector56. The strength of the reflected signals in this example is proportional to distance D and can therefore be used by device10(e.g., by sensor16and/or control circuitry20) to measure changes to distance D and/or changes in the angle between structures in device10.

In the example ofFIG.8, scanning light beam sensor16has a patterned target such as target70. Sensor16ofFIG.8is used in detecting changes in the angular orientation between structures80and82. Patterned target70, which may sometimes be referred to as a target, pattern, fiducial, etc., may include, for example, a bar code or other recognizable pattern. Sensor16may include a light emitter such as scanning light beam emitter74. Emitter74may be a scanning laser device or other devices that emits a beam of light76that is scanned across target70in directions78. Detector72detects corresponding reflected light. Because of the recognizable pattern of target70, lateral shifts in the position of target70can be detected. Sensor16can thereby detect when the angle between structures80and82has changed (e.g., because structure80has shifted laterally in direction85).

If desired, a misalignment sensor may include a strain gauge.FIG.9is a cross-sectional side view of an illustrative strain gauge formed from conductive trace84(e.g., a conductive trace with a serpentine path). Trace84is supported by one or more structures in device10(e.g., portions of housing12, optical modules40, cameras46, etc.). When trace84bends, the effective length of trace84and therefore the resistance of trace84changes. A Wheatstone bridge or other resistance measurement circuitry that is coupled to the terminals of trace84may be used by control circuitry20to measure strain.

In the example ofFIG.9, strain gauge metal trace84has been formed using a laser activation process. This process, which may sometimes be referred to as laser direct structuring, involves exposing laser activatable material such as material86(e.g., polymer with sensitizers or other material that is sensitized to light exposure) to laser light in a desired trace pattern, followed by electrodeposition to grow trace84in the exposed areas. Material86may be formed from a different material than other structures in device10(e.g. material86may be a first shot of polymer and supporting material88may be a second shot of polymer that forms a portion of housing12and/or other structure in a head-mounted device) or a single material may be used in forming these structures. In the example ofFIG.10, strain gauge trace84has been formed on layer90. Layer90may be a layer on structure88(e.g., a dielectric coating layer, a layer of light-sensitive polymer, a flexible printed circuit substrate or other substrate that is attached to structure88using adhesive, welds, fasteners, and/or other attachment mechanisms, etc.).

FIG.11is a cross-sectional side view of an illustrative structure in device10(structure88) showing how a sensor such as strain gauge may be embedded within the structure. Structure88may, as an example, have portions88M (e.g., metal portions) and portions88I (e.g., insulating portions formed from polymer or other dielectric). Sensor16may be a strain gauge formed from strain gauge trace84(e.g., a metal trace) formed in insulator90(e.g. a layer of polymer sandwiched between layers88I). In general, strain gauge sensors may be embedded within structures such as structure88forming housing12, forming optical component packages (e.g., portions of optical modules40, portions of cameras46), and/or other structures in device10.

FIG.12is a cross-sectional side view of an illustrative magnetic sensor. Sensor16includes a permanent magnet such as magnet94and a magnetic sensing device such as a Hall effect sensor or other sensor that can measure magnetic fields (e.g. magnetic sensor92). The measured magnetic field strength at sensor92is a function of distance D between magnet94and sensor92, thereby allowing sensor16to measure distance D (as an example).

Time-of-flight measurements may be made using sensor16, if desired. Consider, as an example, sensor16ofFIG.13. Sensor16ofFIG.13includes a signal emitter such as source96and a signal sensor such as detector98. During operation, source96emits signal102(e.g., a pulse) and detects reflected signal104(e.g., the pulse following reflection of the pulse from the surface of structure110in device10(e.g., a portion of support structure12, optical modules40, cameras46, or other structure in device10). The emitted signal from source96may be an optical signal (light), an acoustic signal (sound such as an ultrasonic acoustic signal), or a radio-frequency signal (e.g., a signal having a frequency of 1 MHz-100 GHz or other suitable radio frequency). Detector98(e.g., a photodetector sensitive to light, a microphone sensitive to sound, or an antenna sensitive to radio-frequency signals) measures the time at which reflected signal104is received relative to the time at which source96emitted signal102. Using the known speed of propagation of signals102and104and the measured time of flight of the emitted signal (e.g., the time between pulse transmission and pulse reception), sensor16and/or control circuitry20can determine the distance D between sensor16and structure100.

If desired, a front-facing display and/or other components (e.g., a touch sensor layer) may be provided on front face F. For example, housing portion12M may include a display cover layer that forms a front member that covers front face F. As shown inFIG.14, a display cover layer (e.g., a display cover layer with a curved cross-sectional profile or other suitable shape) such as display cover layer106(e.g., a front portion of housing portion12M) may overlap a pixel array such as pixel array108(sometimes referred to as a display, display layer, display panel, etc.). Pixel array108may be a liquid crystal display panel, an organic light-emitting display panel, a display panel with other light-emitting diodes, etc.

Display cover layer106may be formed from a layer of glass, clear polymer, or other transparent material that allows pixel array108to be viewed through display cover layer106. During operation, pixel array108may be used in presenting images on front face F (e.g., images that are viewable by the user when device10is not being worn on the user's head and images that are viewable by nearby people when device10is being worn on the user's head). To detect bending of display cover layer106, which may cause cameras46or other optical components mounted on or adjacent to display cover layer106to become misaligned with respect to each other or which may be indicative of bending of housing portion12M that causes optical modules40to become misaligned with respect to each other and/or with respect to cameras46, display cover layer106may be provided with one or more sensors such as sensor16.

Sensor16on display cover layer106ofFIG.14may be, for example, a time-of-flight sensor having a signal emitter such as source96and a signal detector such as detector98. During measurement operations, control circuitry20may use source96to emit signal102. Signal102may reflect from reflector110as reflected signal104, which is detected by detector98. Reflector110may be a structure in housing portion12M such as a portion of display cover layer106or a mirror or other structure that is attached to display cover layer106. The time of flight of the signal from source96to reflector110and back to detector98may be used to compute distance D (e.g., the distance separation different portions of housing portion12M such as different left and right side portions or top and bottom portions of display cover layer106). If bending or other deformation of display cover layer106that is associated with image misalignment is detected, compensating adjustments may be made by control circuitry20.

In the illustrative configuration ofFIG.15, sensor16has a light source such as source112. Light source112may be, for example, a light-emitting diode or a laser that emits a beam of light such as light beam118. Device10may be configured so that light beam118reflects from multiple structures in housing portion12M (e.g., multiple reflectors116) before being detected by detector114of sensor16. Structures116may be mirrors or reflective portions of a chassis or other structural support in housing portion12M, reflective portions of optical modules40, a reflective rear portion of a display cover layer or other structure on front face F of device10, and/or other optical component structures and/or housing structures in device10. Detector114may have an array of photodetectors (e.g., a one-dimensional or two-dimensional array of photodiodes), allowing detector114to detect the position at which light beam118strikes detector114. During operation, deformation of housing portion12M and/or components in device10(e.g., changes in the positions of optical modules40in the example ofFIG.15) may result in image misalignment. This misalignment may be detected by detecting changes in the position at which light beam118illuminates the photodetector array of sensor114.

If desired, interferometry (e.g., optical interferometry) may be used in measuring misalignment. Consider, as an example, the interferometer ofFIG.16. As shown inFIG.16, laser interferometer sensor16ofFIG.16may have a coherent light source such as laser120. A first portion of the light emitted by laser120may pass through beam splitter130, may travel along first interferometer arm126, may reflect from structure128, may reflect from beam splitter130, may travel along second interferometer arm122, may reflect from structure124, and may pass through beam splitter130before reaching light detector134. A second portion of the light emitted by light source120may reflect from beam splitter130toward light detector114. Changes in distance D affect the length of interferometer arm126and therefore affect the phase of the first portion of the light reaching detector134. As a result of interference between the first and second portions of the coherent light reaching detector134, the relative phase of the first and second portions of light (and therefore changes in distance D) can be measured by sensor16. Structure128may be a portion of housing12M, a portion of an optical module or other optical component, or other structure in device10from which it is desired to gather a distance measurement.

If desired, a single light source (e.g. laser112ofFIG.16) may be using in making multiple optical measurements (e.g., multiple time-of-flight measurements, multiple light beam angle measurements of the type described in connection withFIG.15, multiple interferometric measurements, etc.). Optical couplers (e.g., beam splitters, prisms, gratings, etc.) may be used in dividing a single light beam from laser112into multiple light beams to use in one or more of these measurements, thereby reducing the number of light sources used in device10. An illustrative configuration in which three prisms140are being used to split a single beam from laser112into three respective misalignment measurement beams is shown inFIG.17.

As described in connection withFIG.14, front-facing cameras46and/or other optical components may be mounted on or adjacent to a portion of housing portion12M such as display cover layer106. This may help align the front-facing cameras or other optical components. To detect misalignment of images being captured by cameras46, sensors16may be coupled to display cover layer106. As shown inFIG.18, for example, front-facing cameras46may be mounted to the inner surface of display cover layer106and may operate through display cover layer106. Placing cameras46against display cover layer106in this way may help align cameras46(e.g., left and right forward-facing cameras in device10) and may help align the images produced by these cameras. Sensors16may be strain gauges formed from metal traces on the inner surface of display cover layer106or may be strain gauges attached to the inner surface of display cover layer106by adhesive (as an example). In the event that display cover layer106deforms during operation of device10, the misalignment of the images being captured by cameras46can be detected in real time. This allows compensating actions to be taken on the misaligned images (e.g., image warping operations on the image data may be performed). Sensors16may be attached to the inner surface of display cover layer106between each pair of respective cameras46and/or at other locations. If desired, deformation of housing portion12M such as deformation of display cover layer106may be used in compensating for optical module misalignment (e.g., in arrangements in which bending of display cover layer106is associated with misalignment between the images from modules40and eye boxes30).

If desired, multiple sensors16may be used to measure the orientation between optical components and/or other structures in device10(e.g., by triangulation). Consider, as an example, the scenario ofFIG.19. In this example, optical modules40include left and right modules. The orientation between a right-facing surface of a left optical module (surface LH) and a corresponding left-facing surface of a right optical module (surface RH) is being measured using three sensors16(e.g., three distance sensors such as optical sensors or other sensors16of the types described in connection withFIGS.4-18). For example, a first distance sensor may measure a first distance L1between point142on surface LH and corresponding point144on surface RH, a second distance sensor may measure a second distance L2between point146on surface LH and corresponding point148on surface RH, and a third distance sensor may measure a third distance L3between point150on surface LH and corresponding point152on surface RH. By using these three distance measurements (L1, L2, and L3), the relative orientation in X, Y, and Z (including any relative tilt about each of these axes and any changes in position) between the left and right optical modules40(and/or any other pair of structures in device10) can be determined.

In general, the relative positions (including displacement and/or angle) between any pair of structures in device10can be measured using one or more sensors16. Consider, as an example, device10ofFIG.20. As shown inFIG.20, sensors16such as strain gauges on front face F of housing portion12M and/or other structures in device10may measure image misalignment associated with images captured by forward facing cameras46. Sensors16may, for example, measure distance D1(and/or orientation angle) between points154and156on display cover layer106(or other portion of housing portion12M). Additional sensors16may measure distances (and/or orientation angles) such as distance D2(and/or angle) between point158(e.g., a portion of a rigid frame in cover12C, a chassis structure such as a rigid frame in housing portion12M, a left housing wall, etc.) and point160(e.g., a portion of lens barrel32or other optical module structure for a left optical module40), distance D2′ (and/or angle) between point162(e.g., a portion of left optical module40) and point164(e.g., a portion of housing portion12M such as a portion of display cover layer106), distance D3(and/or angle) between point166(e.g., a portion of a left optical module40) and point168(e.g., a portion of a right optical module40), and/or other distances and/or angles between respective portions of device10. As these examples demonstrate, one or more sensors16may be used in measuring the relative orientation between a head-mounted support structure of device10(e.g., a chassis or other device housing structure) and an optical component such as optical module40, between a pair of optical modules40, and/or between different portions of a head-mounted support structure. In configurations in which left and right forward-facing cameras46are mounted to respective left and right optical modules40(e.g., in positions46′ ofFIG.20), measuring the relative orientation between optical modules40serves to measure the relative orientation between the forward-facing cameras. In configurations in which forward-facing cameras46are mounted elsewhere in device10, sensors16can measure the relative position between cameras46, the position between each camera46and housing portion12M, and/or the relative position between each camera46and each optical module40(as examples).

Misalignment between respective cameras (and the images captured by the cameras) between a given camera and a given optical module (and their associated images), and/or between respective optical modules may be measured directly (e.g., by an associated sensor) or indirectly (e.g., by using a first sensor to detect a first misalignment such as a misalignment between a first component and housing portion12M and to detect a second misalignment such as a misalignment between housing portion12M and a second component, thereby producing misalignment information corresponding to misalignment between the first and second components).

Illustrative operations involved in operating device10are shown inFIG.21.

During the operations of block170, sensors16may be used to gather information on the orientation of optical components in device10. Each optical component (e.g., each camera46, each optical module40, etc.) may have a respective sensor16and/or sensors16may measure support structure deformation that is associated with changes in the orientations of the optical components. This allows optical-component-to-optical-component misalignment to be monitored. If desired, structures in housing portion12M (e.g., a display cover layer, a frame or other chassis structure, and/or other optical component support structures, etc.) may be provided with one or more sensors16and/or one or more sensors16may be used in measuring optical-component-to-support-structure orientation. In this way, optical-component-to-optical component misalignment and corresponding image misalignment may be measured directly or indirection. Position measurements may be associated with camera-to-camera alignment, camera-to-optical-module alignment, camera-to-housing alignment, optical module-to-housing alignment, optical-module-to-optical-module alignment, and/or housing-to-housing alignment and each of these measurements may be associated with potential misalignment between images, between an image and an eye box, etc.

During the operations of block172, control circuitry20may process image data (captured images from cameras46and/or displayed images on optical modules40) to compensate for misalignment measured by sensors16during the operations of block170. For example, if it is determined that an optical module (e.g., a right-hand optical module) is presenting an image that has become rotated counterclockwise by angle A relative to an eye box, compensating image warping may be performed on the image to rotate the image clockwise by angle A and thereby compensate for the misalignment. Camera images may likewise be warped. The image warping transforms that are applied during misalignment compensation operations may include geometrical transforms such as shifts, shears, rotations, etc.

Consider, as an example, a scenario in which sensors16determine that first and second optical components (e.g., a pair of cameras46, a pair of modules40, a camera and a module, etc.) are misaligned with respect to each other. During the image compensation operations of block172, control circuitry20may, based on the measured misalignment, warp a first image captured by or displayed by the first optical component and/or may warp a second image captured by or displayed by a second optical component, thereby compensating the images for the measured misalignment.

As shown by line174, the optical component orientation measurements of block172to detect component and image misalignment and the corresponding misalignment compensation image processing adjustments that are performed at block172may be performed continuously (e.g., upon detection of a drop event, upon power up, in response to a user-initiated calibration sequence during which a user is asked to move device10so that sensors60can detect misalignment, in accordance with a predetermined schedule, etc.).

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's, home addresses, data or records relating to a user'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.

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.

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'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'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.

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.