Head-mounted electronic device with self-mixing sensor

Abstract

A head-mounted device can have a head-mounted housing and optical components supported by the head-mounted housing. The optical components can include cameras, movable optical modules, and other components. Each optical module can include a display that displays an image and a lens that provides the image to a corresponding eyebox. Optical self-mixing sensors can 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 can be adjusted to move the optical component or other actions can be taken to compensate for the change.

Description

[0001] This application claims priority to U.S. Patent Application No. 17 / 230,341 filed April 14, 2021 and U.S. Provisional Patent Application No. 63 / 028,458 filed May 21, 2020, which are hereby incorporated by reference in their entirety. TECHNICAL FIELD

[0002] The present disclosure relates generally to electronic devices, and more particularly to electronic devices with optical components, such as head-mounted devices. BACKGROUND

[0003] Electronic devices, such as head-mounted devices, can have displays for displaying images, and can have other optical components. SUMMARY

[0004] A head-mounted device is disclosed that can have a head-mounted housing. An optical component can be supported by the head-mounted housing. The optical component can include a camera, such as a forward-facing camera, and / or an optical module with a display for displaying images to an eye box.

[0005] An optical self-mixing sensor can be provided in a head-mounted device to detect changes in position between parts of the head-mounted device. These changes can include changes in position between optical module components, such as lenses and displays. These changes can also involve movement of optical components, such as cameras.

[0006] In response to detecting a change in optical component position using the optical self-mixing sensor (e.g., a change indicating that a component or other structure has moved from its expected position), an actuator in the device can be adjusted to move the optical component or other actions can be taken to compensate for the change. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a top view of an illustrative head-mounted device in accordance with an embodiment.

[0008] Figure 2 is a rear view of an illustrative head-mounted device in accordance with an embodiment.

[0009] Figure 3 is a schematic diagram of an illustrative head-mounted device in accordance with an embodiment.

[0010] Figure 4 is a diagram of an illustrative self-mixing sensor in accordance with an embodiment.

[0011] Figure 5 includes a graph illustrating operation of a self-mixing sensor in accordance with an embodiment. Figure 4 includes a graph illustrating operation of a self-mixing sensor in accordance with an embodiment.

[0012] Figure 6 This is a cross-sectional side view of an illustrative display system based on one implementation scheme.

[0013] Figure 7 This is a cross-sectional side view of an exemplary camera system according to one implementation scheme.

[0014] Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 This is a cross-sectional side view of an exemplary optical system with a self-mixing sensor according to an implementation scheme.

[0015] Figure 14 This is a flowchart illustrating an exemplary operation associated with operating an electronic device having a self-mixing sensor, according to one implementation scheme. Detailed Implementation

[0016] Electronic devices, such as head-mounted devices, may have optical components. These optical components may include optical modules for providing an image to a user's eyes. Head-mounted devices may also have other optical components, such as cameras. If a head-mounted device is subjected to stress during a drop event or other high-stress event, components within the device may experience misalignment. To ensure satisfactory device operation, optical self-mixing sensors can be used to accurately measure the position of components within the head-mounted device. An actuator can then move the optical components to compensate for any detected changes in position and / or may take other compensatory actions.

[0017] Figure 1 A top view of an illustrative head-mounted device is shown. (See attached image.) Figure 1 As shown, a head-mounted device, such as electronic device 10, may have a head-mounted support structure, such as housing 12. Housing 12 may include portions (e.g., head-mounted support structure 12T) for allowing the device 10 to be worn on a user's head. Support structure 12T may be formed of fabric, polymer, metal, and / or other materials. Support structure 12T may form a strap or other head-mounted support structure to help support the device 10 on the user's head. The main support structure of housing 12 (e.g., a head-mounted housing such as main housing portion 12M) may support electronic components such as display 14.

[0018] The main housing portion 12M can include a housing structure formed from metal, polymer, glass, ceramic, and / or other materials. For example, the housing portion 12M can have a housing wall on the front face F and housing walls on the adjacent top, bottom, left, and right faces formed from rigid polymer or other rigid support structure, and these rigid walls can optionally be covered with electronic components, fabric, leather, or other soft materials, etc. The housing portion 12M can also have internal support structures such as frames and / or structures that perform a variety of functions such as controlling airflow and heat dissipation while providing structural support. The walls of the housing portion 12M can enclose the internal components 38 in the internal region 34 of the device 10, and can separate the internal region 34 from the environment (external region 36) surrounding the device 10. The internal components 38 can include integrated circuits, actuators, batteries, sensors, and / or other circuitry and structures for the device 10. The housing 12 can be configured to be worn on a user's head, and can form eyewear, a hat, a helmet, goggles, and / or other head-mounted device. Configurations in which the housing 12 forms goggles are sometimes described herein as examples.

[0019] The front face F of the housing 12 can face outward away from a user's head and face. The opposite back face R of the housing 12 can face a user. Portions of the housing 12 located on the back face R (e.g., portions of the main housing 12M) can form a cover, such as the cover 12C. The presence of the cover 12C on the back face R can help hide internal housing structures, internal components 38, and other structures in the internal region 34 from view by a user.

[0020] The device 10 can have one or more cameras, such as the cameras 46. Figure 1 For example, forward (front-facing) cameras can allow the device 10 to monitor movement of the device 10 relative to the environment surrounding the device 10 (e.g., the cameras can be used to form part of a vision odometry system or a vision-inertial odometry system). Forward-facing cameras can also be used to capture images of the environment for display to a user of the device 10. If desired, images from multiple forward-facing cameras can be merged with each other and / or forward-facing camera content can be merged with computer-generated content for the user.

[0021] The device 10 can have any suitable number of cameras 46. For example, the device 10 can have K cameras, where K has a value of 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. The cameras 46 can be sensitive at infrared wavelengths (e.g., the cameras 46 can be infrared cameras), can be sensitive at visible wavelengths (e.g., the cameras 46 can be visible cameras), and / or the cameras 46 can be sensitive at other wavelengths. If desired, the cameras 46 can be sensitive at both visible and infrared wavelengths.

[0022] A camera 46 mounted on the front face F and facing outward (toward the front of the device 10 and away from the user) can sometimes be referred to herein as a front-facing or front camera. The camera 46 can capture visual ranging information, image information processed to locate objects in the user's field of view (e.g., so that virtual content can be properly registered with respect to real-world objects), image content for display in real-time for the user of the device 10, and / or other suitable image data.

[0023] The device 10 can have left and right optical modules 40. The optical modules 40 support electronic and optical components such as light-emitting components and lenses, and thus can sometimes be referred to as optical assemblies, optical systems, optical component support structures, lens and display support structures, electronic component support structures, or housing structures. Each optical module can include a respective display 14, lens 30, and support structure such as support structure 32. The support structure 32, which can sometimes be referred to as a lens support structure, optical component support structure, optical module support structure, optical module portion, or lens barrel, can include a hollow cylindrical body structure with an open end or other support structure for housing the display 14 and lens 30. The support structure 32 may, for example, include a left lens barrel supporting the left display 14 and left lens 30 and a right lens barrel supporting the right display 14 and right lens 30.

[0024] The display 14 can include an array of pixels or other display device to produce an image. The display 14 may, for example, include organic light-emitting diode pixels formed on a substrate with thin film circuitry and / or formed on a semiconductor substrate, pixels formed from crystalline semiconductor dies, liquid crystal display pixels, scanning display devices, and / or other display devices for producing an image.

[0025] The lens 30 can include one or more lens elements for providing image light from the display 14 to a respective eyebox 13. The lens can be implemented using refractive glass lens elements, using catadioptric lens structures (catadioptric lenses), using Fresnel lenses, using holographic lenses, and / or other lens systems.

[0026] The displays (display panels) 14 operate together to form the display of the device 10 when the user's eyes are positioned in the eyeboxes 13 (e.g., the user's eyes can view the images provided by the respective left and right optical modules 40 in the eyeboxes 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 the right optical module when the user views the displays.

[0027] It can be desirable to monitor the user's eyes when the user's eyes are located in the eyebox 13. For example, it can be desirable to use a camera to capture images of the user's iris (or other parts of the user's eyes) for user authentication. It can also be desirable to monitor the direction of the user's gaze. Gaze tracking information can be used as a form of user input and / or can be used to determine where in the image the image content resolution should be locally enhanced in a foveated imaging system. To ensure that the device 10 is able to capture satisfactory eye images when the user's eyes are located in the eyebox 13, each optical module 40 can be provided with a camera (such as the camera 42) and one or more light sources (such as light emitting diodes 44) or other light emitting devices (such as lasers, lamps, etc.). The camera 42 and light emitting diodes 44 can operate at any suitable wavelengths (visible, infrared, and / or ultraviolet). For example, the diodes 44 can emit infrared light that is not visible (or is barely visible) to the user. This allows eye monitoring operations to be performed continuously without interfering with the user's ability to view images on the display 14.

[0028] Not all users have the same interpupillary distance IPD. To provide the device 10 with the ability to adjust the interpupillary distance between the modules 40 along the lateral dimension X, and thus the distance IPD between the eyeboxes 13, to accommodate different user interpupillary distances, the device 10 can be provided with an optical module positioning system in the housing 12. The positioning system can have guide members and actuators 43 for positioning the optical modules 40 relative to each other.

[0029] The actuators 43 can be manually controlled and / or computer controlled actuators (e.g., computer controlled motors) for moving the support structures 32 (lens barrels) relative to each other. Information about the position of the user's eyes can be gathered using, for example, the camera 42. The position of the eyeboxes 13 can then be adjusted accordingly.

[0030] As shown in a rear view of the device 10 of Figure 2 The cover 12C can cover the back face R while leaving the lenses 30 of the optical modules 40 uncovered (e.g., the cover 12C can have openings aligned with and receiving the modules 40). As the modules 40 are moved relative to each other along the dimension X to accommodate different interpupillary distances of different users, the modules 40 are moved relative to a fixed housing structure such as the wall of the main portion 12M and relative to each other.

[0031] Figure 3 A schematic diagram of an illustrative electronic device such as a head-mounted device or other wearable device is shown in FIG. 1. Figure 3Device 10 can operate as a standalone device and / or resources of device 10 can be available to communicate with external electronic equipment. For example, communication circuitry in device 10 can be used to transmit user input information, sensor information, and / or other information to external electronic devices (e.g., wirelessly or via a wired connection). Each of these external devices can include Figure 3 components of the type shown in device 10.

[0032] As shown in FIG. 1, a head-mounted device such as device 10 can include control circuitry 20. Control circuitry 20 can include storage and processing circuitry to support operation of device 10. This storage and processing circuitry can 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), and / or the like. Processing circuitry in control circuitry 20 can be used to gather input from sensors and other input devices, and can be used to control output devices. The processing circuitry can be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors and other wireless communication circuitry, power management units, audio chips, application-specific integrated circuits, and / or the like. During operation, control circuitry 20 can use display 14 and other output devices to provide visual output and other output to a user. Figure 3

[0033] To support communication between device 10 and external equipment, control circuitry 20 can use communication circuitry 22 to communicate. Circuitry 22 can include antennas, radio-frequency transceiver circuitry, and other wireless communication circuitry and / or wired communication circuitry. Circuitry 22 (which can sometimes be referred to as control circuitry and / or control and communication circuitry) can support two-way wireless communication 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 pointing device, computer stylus, or other input device, a speaker or other output device, etc.) via a wireless link. For example, circuitry 22 can include radio-frequency transceiver circuitry such as wireless local area network transceiver circuitry configured to support communication via a wireless local area network link, near-field communication transceiver circuitry configured to support communication via a near-field communication link, cellular telephone transceiver circuitry configured to support communication via a cellular telephone link, or transceiver circuitry configured to support communication via any other appropriate wired or wireless communication link. For example, communication can be via a Bluetooth® link, link, ​Wireless communication is supported by the link, a wireless link operating at frequencies between 10 GHz and 400 GHz, a 60 GHz link or other millimeter wave link, a cellular telephone link, or other wireless communication link. Device 10, if desired, can include power supply circuitry for transmitting and / or receiving wired and / or wireless power, and can include a battery or other energy storage device. For example, device 10 can include a coil and a rectifier to receive wireless power provided to circuitry in device 10.

[0034] Device 10 can include input-output devices such as device 24. Input-output device 24 can be used to gather user input, to gather information about a user’s surroundings, and / or to provide output to a user. Device 24 can include one or more displays, such as display 14. Display 14 can include one or more display devices, such as an organic light-emitting diode display panel (a panel formed with organic light-emitting diode pixels on a polymer or silicon substrate that contains pixel control circuitry), a liquid crystal display panel, a microelectromechanical systems display (e.g., a two-dimensional mirror array or a scanning mirror display device), a display panel with an array of pixels formed from crystalline semiconductor light-emitting diode dies (sometimes referred to as microLEDs), and / or other display devices.

[0035] The sensors 16 in the input-output devices 24 can 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 touch sensors forming buttons, touchpads, or other input devices, and other sensors. If desired, the sensors 16 can include optical sensors such as optical sensors that emit and detect light, ultrasonic sensors, optical touch sensors, optical proximity sensors, and / or other touch and / or proximity sensors, monochrome 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 contactless gestures ("mid-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 containing 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 stereoscopic 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, line-of-sight tracking sensors, electromyography sensors that 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, the device 10 can use the sensors 16 and / or other input-output devices to gather user input. For example, buttons can be used to gather button press input, touch sensors overlaid with a display can be used to gather user touch screen input, touchpads can be used to gather touch input, microphones can be used to gather audio input (e.g., voice commands), accelerometers can be used to monitor when a finger contacts an input surface and thus can be used to gather finger press input, etc.

[0036] If desired, the electronic device 10 can include additional components (see, e.g., other devices 18 in the input-output devices 24). The additional components can 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 the housing and / or display structures, other optical output devices, and / or other circuitry for gathering input and / or providing output. The device 10 can also include a battery or other energy storage device, connector ports for supporting wired communication with auxiliary equipment and for receiving wired power, and other circuitry.

[0037] It can be 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 in which stress is placed on device 10, there is a risk that the position of a display, lens, camera, other optical component, and / or other structure in device 10 will move relative to its initial position. To ensure that device 10 operates satisfactorily, even when subjected to substantial stress, device 10 can use sensors to measure component position. In response to measuring a change in component position, device 10 (e.g., control circuit 20) can take compensating action (e.g., by using actuators to adjust the position of a component to ensure that the component is satisfactorily positioned, by warping image data associated with a camera or display to compensate, etc.). In illustrative configurations that can be described herein as examples from time to time, one or more actuators can be used to reposition an optical component that has moved 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 operation of optical components can also be described herein as examples.

[0038] It can be desirable to measure relatively small changes in component position so that a component can be maintained in a desired position. For example, it can be desirable to maintain the position of a lens or other component within a tolerance of less than 30 microns, less than 20 microns, less than 7 microns, or less than 3 microns of its original position (as examples). In maintaining tight tolerances for optical components in device 10, it can be desirable to make correspondingly accurate position measurements. In illustrative configurations described herein as examples, optical position sensors such as optical self-mixing sensors are used to measure component position within these tight tolerances (e.g., with accuracies better than 10 microns, better than 2 microns, or better than 1 micron or other suitable accuracy). Sub-micron position measurement accuracy or other satisfactory measurement precision allows lenses, displays, cameras, and / or other optical components to be placed in desired positions without introducing significant misalignment errors.

[0039] Figure 4An illustrative optical self-mixing sensor is shown. The self-mixing sensor 70, sometimes referred to as an optical self-mixing position sensor or self-mixing orientation sensor, can be used to measure distances and thus determine the relative position between the sensor and the target structure. In some configurations, one or more self-mixing sensors can be used to measure angular orientation. For example, angular tilt can be measured by measuring two or more distances. For instance, a pair of distance measurements taken at different corresponding locations on a component can be used to measure tilt about one axis, while three such distance measurements can be used to measure tilt about two axes. Arrangements in which the self-mixing sensors are referred to as measuring distances, displacements, or positions may sometimes be described herein as examples. Typically, position, angular orientation, changes in position and / or orientation, and / or other self-mixing sensor measurements can be directly acquired and / or derived from measurements of distances from the self-mixing sensor.

[0040] exist Figure 4 In the example, the self-mixing sensor 70 is being used to measure the distance (D) between the sensor 70 and the target 82. The target structure in device 10 (such as...) Figure 4 Target 82) could be a portion of a lens (e.g., Figure 1 The lens 30), a portion of the support structure (e.g., the lens barrel or other support structure 32 for the lens and / or other optical module components), a display structure (e.g., display 14), a portion of the camera (e.g., camera 46 and / or camera 42), and / or other structures in the device 10 (e.g., the housing structure in portion 12M). A self-mixing sensor, such as sensor 70, may be mounted on or adjacent to the housing structure (e.g., the structure in portion 12M), and / or sensor 70 may be mounted on the lens (e.g., the lens 30), a portion of the support structure (e.g., the lens barrel or other support structure 32 for the lens and / or other optical module components), a display structure (e.g., display 14), a portion of the camera (e.g., camera 46 and / or camera 42), and / or other structures in the device 10 (e.g., the housing structure in portion 12M). Figure 1 The lens 30, the support structure (e.g., lens barrel 32), the display structure (e.g., display 14), the camera section, and / or other structures in device 10 (e.g., the housing structure in section 12M) are mounted on or near it. In this way, the distance D can correspond to the display-to-lens measurement result or the housing-to-lens measurement result, which shows information about lens alignment and / or can also be used to measure the distance between the lens, camera, display, housing structure, etc. If the measurement results of one or more sensors 70 show that a component is misaligned relative to its desired position, a compensatory action can be taken. For example, control circuitry 20 can use actuators to move the lens, display, camera, or other component in device 10 to compensate for the measured change in the component's position. If, for example, lens 30 is 30 micrometers away from display 14, lens 30 can be moved 30 micrometers toward display 14.

[0041] like Figure 4As shown in the illustrative configuration of FIG. 1, self-mixing sensor 74 can include a laser such as vertical cavity surface emitting laser 80 (e.g., self-mixing proximity sensor 70 can be a coherent self-mixing sensor with a diode laser or other coherent or partially coherent source of light or other electromagnetic radiation). Laser 80 can have thin film interference mirrors 74 (sometimes referred to as Bragg reflectors) each formed from a stack of thin film layers of alternating refractive index. An active region 76 can be formed between mirrors 74. The lower mirror in laser 80 can have a nominal reflectivity less than 100% to allow some light from laser 80 to reach an overlaying photodiode 72, or in configurations where photodiode 72 is located elsewhere in sensor 70 (e.g., laterally adjacent to laser 80), the lower mirror can have a nominal reflectivity of 100%. The upper mirror in laser 80 can have a slightly lower reflectivity so that laser 80 emits light 84 toward a target 82. Laser 80 can be controlled by applying a drive signal to a terminal 86 using control circuit 20 (e.g., a drive circuit in circuit 20). Sensing circuitry (e.g., photodiode 72 and / or associated sensing circuitry in circuit 20) can measure the light output of laser 80 (as an example).

[0042] The infrared wavelengths of emitted light 46 can be 850-1200 nm, 800-1100 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 wavelengths (e.g., visible wavelengths, ultraviolet wavelengths, infrared wavelengths, near-infrared wavelengths, etc.). When emitted light 84 illuminates target 82, some of the emitted light will reflect back toward sensor 70 as reflected light 86 (e.g., specularly reflected light from target 82 and / or backscattered light from a matte surface in target 82).

[0043] Figure 4 Sensor 70 includes a light sensitive element (e.g., a photodetector such as photodiode 72). Figure 4 Photodiode 72 in the example of FIG. 1 is located below laser 80, but if desired, configurations can be used in which photodiode 72 is adjacent to laser 80, on a separate substrate outside of laser 80, above active region 76, and / or has other configurations. Terminals of photodiode 72 can be coupled to sensing circuitry in control circuit 20. This circuitry acquires a photodiode output signal that is generated in response to receiving reflected light (specularly reflected and / or backscattered portions of emitted light 84) such as reflected light 86. In addition to using a photodiode, laser junction voltage measurements (e.g., if laser is driven with a constant bias current) or laser bias current (e.g., if laser is driven with a constant voltage) can be used to detect self-mixing.

[0044] Target 82 is located at a distance D from proximity sensor 70. A portion of light 84 that is reflected or backscattered as reflected light 86 from target 82 re-enters the laser cavity of laser 80 (i.e., such backfeed light mixes with light in the laser cavity), coherently perturbing the electric field and causing perturbations in carrier density in laser 80. These perturbations in laser 80 cause coherent self-mixing fluctuations in the power of emitted light 84 and in the associated operating characteristics of laser 80, such as laser junction voltage and / or laser bias current. These fluctuations can be monitored. For example, the power fluctuations of light 86 can be monitored using photodiode 72. In Figure 4 In the example, photodiode 72 is an integrated monolithic photodiode formed beneath laser 80, although other configurations can be used if desired.

[0045] Control circuit 20 is configured to supply a drive current for laser 80, and includes circuitry for sensing the response of photodiode 72. The sensed photodiode output can include measurements of diode current and / or voltage. A modulation scheme can be used to drive laser 80 for inducing wavelength modulation, and a photodiode output processing scheme (using measurements of photodiode current, junction voltage, bias current, etc.) can be used to process the self-mixing fluctuations in the measured output power to allow control circuit 20 to determine the distance D between sensor 70 and target 82 in accordance with the principles of self-mixing interferometry.

[0046] The modulation scheme used to drive laser 80 may, for example, use a triangular wave drive signal that, due to the dependence of the output wavelength on the drive current magnitude of laser 80, continuously changes the wavelength of light 84 between a first wavelength WL1 and a second wavelength WL2 during each half cycle of the triangular wave. The wavelength changes of light 84 cause the self-mixing interference signal of laser 80 to exhibit a ripple. Other modulation schemes can be used to drive laser 80 if desired (e.g., a sinusoidal drive scheme, etc.).

[0047] The processing scheme for the photodiode signal uses a frequency extraction transform to extract the period of the ripple from which the distance D can be computed. The distance D can be determined, for example, 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 the position of a lens or other optical component within device 10 can be determined with sufficient precision to allow an actuator 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 time resolution (e.g., a wavelet transform) or no time resolution (e.g., a Fourier transform).

[0048] Figure 5 An exemplary signal processing method for sensor 70 is shown in the figure.

[0049] Figure 5 The first (topmost) trace illustrates how an alternating current (AC) signal (such as a triangular wave) can be used to modulate the laser drive current Id of laser 80. This modulates the temperature of laser 80 and thus modulates the output wavelength of light 84. For example, the wavelength of light 84 can vary between a first value WL1 (when the drive signal Id is minimum) and a wavelength WL2 (when the drive signal Id is maximum). According to the principle of self-mixing interferometry, the modulation of the wavelength of light 84 allows a self-mixing proximity sensor to measure the target distance D without changing the distance D.

[0050] Figure 5 The second (second uppermost) trace illustrates how the resulting output signal PDout from photodiode 72 contains self-mixing interference ripple 60. In a configuration for measuring laser current or laser voltage, the self-mixing interference ripple will appear in the measured current or voltage.

[0051] Control circuit 20 (e.g., a sensing circuit based on operational amplifier circuitry or other sensing circuitry) can be configured to distinguish the signal PDout (or the measured current or voltage of laser 80). Therefore, control circuit 20 (e.g., the sensing circuitry of circuit 20) can generate an output signal Vsig, such as... Figure 5 The third (topmost) trace is shown. The signal Vsig is ideally a square wave to which ripple 60 is applied. To facilitate subsequent signal processing (e.g., processing to perform frequency extraction transformation), the average value of the signal Vsig during the high period 64 can be subtracted from the signal Vsig during the high period 64 (digitally or using analog circuitry in control circuitry 20), thereby equalizing the DC component in periods 62 and 64, as shown by... Figure 5 The signal V in the fourth (lowest) trace is shown.

[0052] 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.) can be applied to the signal V to determine the frequency of the ripple 60. With one illustrative method, the ripple frequency can be determined by identifying the frequency associated with a peak in the FFT amplitude curve. It can be assumed that the frequencies with lower peaks in the FFT output are associated with noise and can be ignored. A more accurate frequency evaluation 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 output frequency of the FFT algorithm to identify the ripple frequency). For example, a curve such as a Gaussian curve can be fit to the frequency peaks of the output of the FFT process to accurately identify the ripple frequency fp. The frequency fp can then be used to calculate the target distance D. In some illustrative configurations, other types of demodulation can be used to determine the distance D. For example, IQ demodulation can be used in scenarios where the laser 80 is sinusoidally modulated. If desired, a separate phase modulator (e.g., a separate electro-optical modulator such as a lithium niobate electro-optical modulator) can be used to modulate the light 84. These self-mixing modulation and signal processing arrangements and / or other arrangements can allow distances such as the distance D to be measured in the device 10 so that this distance information can be used to adjust components in the device 10.

[0053] Accurate distance measurements of the type that can be produced using the sensor 70 can be used to provide real-time feedback on the position of optical components within the device 10. For example, sensors such as the sensor 70 can be used to measure the position of lenses, displays, image sensors, and / or other optical components and / or housing structures used to support such components so that the control circuit 20 can adjust actuators to reposition the components and / or other appropriate actions can be taken.

[0054] For example, consider the arrangement of Figure 6 In the example of Figure 6 A first sensor 70 can measure the distance Dl between the display 14 and the lens 30 (e.g., along the right-hand edge of the lens 30), and a second sensor 70 can measure the distance D2 between the display 14 and the lens 30 (e.g., along the left-hand edge of the lens 30). If desired, a third sensor 70 can measure the separation between the lens 30 and the display 14 (e.g., so that the angular orientation of the lens 30 in all dimensions can be determined).

[0055] By using sensor 70, the distance between lens 30 and display 14 and the orientation of lens 30 relative to display 14 can be measured. Using this type of arrangement, undesired movement of lens 30 relative to display 14, undesired movement of lens 30 relative to other structural members in housing chassis or housing portion 12M, undesired movement of display 14 relative to lens 30 and / or housing portion 12M, and / or other undesired movement of portions of optical module 40 in device 10 can be detected.

[0056] If needed, sensor 70 can also be used to actively monitor the position of lens 30 during ongoing lens position adjustment to change the distance of the virtual image as the user views the content on display 14 from eye-fitting frame 13. Such lens position adjustment can be performed, for example, to adjust the focus of module 40, and thereby adjust the amount of adaptation required for the user to view the image on display 14. For example, control circuitry 20 can adjust the lens focus to minimize or eliminate vergence-accommodation mismatch when the 3D content associated with the left and right images on the left and right optical modules 40 is being presented to the user.

[0057] exist Figure 7 In this exemplary configuration, sensor 70 is being used to monitor the camera as camera 46 captures an image of real-world object 90. Figure 7 The relative position between the camera lens 30' and the camera image sensor 46I in the example camera 46). A first sensor 70 may, for example, measure distance D1, while a second sensor measures distance D2. Additional sensors 70 may be used if necessary. In this way, the positions of the lens 30', image sensor 46I, and / or associated housing structures can be measured during operation of the device 10, allowing appropriate actions to be taken (e.g., compensating for movement of the lens 30', image sensor 46I, etc.).

[0058] Figure 8 This is a cross-sectional side view of a portion of an exemplary optical module having sensor 70. Figure 8 In this example, the optical module 40 includes a lens 30 (e.g., a reflective or refractive lens or other lens) and a display 14 (e.g., a display with an organic light-emitting diode array). The lens 30 may be supported within an optical module support structure 32 (e.g., a lens barrel). The self-mixing sensor 70 and the display 14 may be supported by support structures 92 and 94, respectively. The display 14 and the support structure 94 may be coupled to the support structure 32 (e.g., structure 94 may be part of the lens barrel structure), or as... Figure 8As shown, structure 94 can be a structure separate from support structure 32 (e.g., a support structure in housing portion 12M, a display substrate of a display panel associated with display 14) and optionally coupled to support structure 32.

[0059] During operation, control circuitry 20 can use sensor 70 to measure the position of lens 30. For example, sensor 70 can be mounted directly to a support structure, such as support structure 92 (e.g., a chassis or other housing structure in housing portion 12M) that is separate from support structure 32 of optical module 40 and thus serves to establish a fixed reference coordinate system from which the position of lens 30 can be measured. Figure 8 In arrangements in which display 14 and support 94 are attached to support 92, Figure 8 The sensing arrangement of

[0060] In response to information gathered by sensor 70 regarding the position of lens 30, control circuitry 20 can use actuator 96 to adjust the position of lens 30 (e.g., the position of lens 30 relative to support structure 92 and display 14). If desired, actuator 96 can be mounted between support structure 92 (which serves as a fixed reference coordinate system) and lens 30. Actuator 96 can be a piezoelectric actuator, an electromagnetic actuator (e.g., a motor), and / or other computer-controlled positioner. Two or more, three or more, or other suitable number of actuators 96 can be used to position lens 30. For example, three actuators 96 spaced 120° apart from one another around the perimeter of lens 30 can be used to adjust the orientation of lens 30. Actuator 96 can adjust the spacing along axis Z between display 14 and lens 30, and / or can be configured to shift lens 30 laterally (e.g., along dimensions X and / or Y).

[0061] Adhesive can be used to mount lens 30 to support structure 32. In this type of arrangement, there can be a possibility of 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 Figure 8 The arrangement of

[0062] If desired, the position of lens 30 can be measured directly (rather than indirectly through measurement of lens barrel position and inference of lens position from the measured lens barrel position as Figure 8 shown. Figure 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 is reflected directly from the inward-facing surface of lens 30).

[0063] If necessary, other direct lens position sensing arrangements can be used. Figure 10 In this example, 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 exemplary configuration, each sensor 70-1 emits light 84 that propagates in the XZ plane and thus measures the lens position along this first direction; each sensor 70-2 emits light 84 that propagates in the YZ plane and thus measures the lens position along this second direction, different from the first direction; and each sensor 70-3 emits light 84 that propagates in the Z direction (e.g., a direction different from the first and second directions). Using this configuration, sensors 70-1 and 70-2 can detect lateral movement of the lens 30 (e.g., along...). Figure 10 (Motion along the X and Y axes). Each sensor 70-3 measures distance only along the Z dimension (in this example), thus separating these Z-axis measurements from the lateral position measurements made using sensors 70-1 and 70-2.

[0064] exist Figure 11 In the example, an array of self-mixing sensors 70 (e.g., a dense array having at least 10, at least 100, less than 1000, less than 50, or other suitable number of items) has been provided in device 10. Sensors 70 may face an inward-facing surface of lens 30 (e.g., lens surface 98). During operation, sensors 70 may sense the position of surface 98 and thereby measure the deformation of the shape of surface 98. This information may be dynamically used by control circuitry 20 (e.g., to adjust lens 30 by deforming the shape of surface 98 and / or by moving lens 30, adjustment 14, and / or to adjust other structures in device 10 using actuators, such as adjusting image data by distorting the image displayed on display 14 to compensate for lens distortion, etc.). If desired, Figure 11 The array of sensors 70 may be located behind the display 14 (for example, the display 14 may be partially transparent, allowing light from the sensors 70 to pass through the display 14).

[0065] Figure 12 Another illustrative arrangement is shown below. For example... Figure 12 As shown in the configuration, one or more sensors 70 may be mounted on a support structure 94 (e.g., a housing support structure, a display panel substrate of the display 14 and / or forming part of the display 14 and / or directly attached to the display 14 and / or other structures supporting the display).

[0066] Figure 13It is shown how the lens 30 can be provided with a planar surface, such as surface 98P or other surface that is offset from the interior optical surface 98 of the lens 30. The planar surface 98P can help to enhance optical feedback to the sensor 70 by increasing the amount of reflected light from the sensor 70 from the surface of the lens 30 back to the sensor 70. In the absence of a surface, such as the surface 98P, that is oriented to reflect light 84 back to the sensor 70, the light 84 can tend to reflect in a direction that is also not aligned with the sensor 70.

[0067] The sensor 70 can be used to measure the position of the lens 30 and / or other lenses (e.g., camera lenses) in the optical module 40. For example, one or more sensors 70 can be used to measure the position of the left lens in the left optical module, and one or more sensors 70 can be used to measure the position of the right lens in the right optical module. The control circuit 20 can measure the lens position separately for the left and right optical modules 40, and can adjust the lens position using separately adjustable actuators 96 for the left and right optical modules. The ability to separately control the left and right lens-to-display spacings can help users with visual impairments, such as users with different optical power (eyeglass prescriptions) for their left and right eyes, reducing or eliminating the need to provide modules 40 with user-specific corrective lenses.

[0068] If desired, the actuators 96 can be used to shake (e.g., vibrate) the lenses (e.g., the lens 30) to dislodge dust and / or other debris from the surfaces of the lenses. Such actuator-based cleaning arrangements can be particularly helpful for cleaning inward-facing lens surfaces, such as the surface 98 of the lens 30, as these surfaces can not be easily accessible by a user. Vibrations for cleaning the lenses (such as the lens 30) in the optical module 40 can be applied to the lenses whenever the device 10 is powered on and / or at other suitable times.

[0069] Figure 14 Exemplary operations associated with using the device 10 are shown in FIG. 6.

[0070] Measurements of the position can be made by the control circuit 20 at suitable times (e.g., upon power on, in response to detecting a drop event with an inertial measurement unit and / or other sensors in the device 10, in response to a user command, according to a schedule, etc.) (block 110).

[0071] During operation of block 110, sensor 70 can measure a distance D between sensor 70 and an adjacent structure in device 10. Distance D can correspond to a distance between sensor 70 and some structure, such as a lens surface of lens 30 and / or a lens barrel, display 14 (e.g., a display substrate and / or other display structure), a camera, a support structure in device 10 for supporting portions of optical module 40 such as lens 30 and / or display 14, a support structure in device 10 for supporting other optical components, and / or other structures. Sensor 70 can be coupled to lens 30, display 14, a lens barrel (support structure 32), a display support structure, a housing structure such as a structure for supporting a camera, a camera, and / or other structures in device 10. In this way, information about the relative and / or absolute position of these structures and thus associated information about the translational and / or angular alignment and orientation of these structures (e.g., information about misalignment of these structures relative to their desired alignment, such as information about lens alignment, display alignment, optical module alignment, lens surface shape, camera alignment, housing structure alignment, and / or other information about how structures in device 10 can be misaligned relative to their desired positions) can be gathered. In systems with variable focus (e.g., systems in which the distance between lens 30 and display 14 in optical module 40 is adjusted to adjust the focus to place computer-generated content at various different virtual image distances on display 14 to help reduce the visual vergence accommodation mismatch), information about misalignment caused by a deviation between the position of lens 30 and its desired adjusted position can be gathered by sensor 70.

[0072] During operation of block 112, control circuit 20 can adjust adjustable components in device 10 based on the measurements from sensor 70. For example, actuators in device 10 can be adjusted to reposition lens 30, display 14, optical module 40, support structure 32, camera 46, support structures in housing portion 14M, and / or other structures in device 10. In this way, detected misalignments in the position of components (e.g., misalignments of lenses, displays, support structures, portions of lenses that cause lens deformation, image sensors, camera lenses, other portions of camera 46, and / or other components and / or structures in device 10 relative to one another) can be corrected. In an illustrative configuration, in response to detecting that lens 30 is not currently at its desired position, actuator 96 can move the lens to the desired position (e.g., lens 30 can be moved laterally in dimension X and / or Y by tilting about the X, Y, and / or Z axes at an angle, moved vertically in dimension Z, etc.). If desired, the shape of lens 30 can be changed using an actuator (e.g., by applying a force that deforms lens 30). This allows for correction of undesirable lens shape.

[0073] In addition to or instead of moving or otherwise physically adjusting all or some of the components in optical module 40, the camera in device 10, and / or other optical components and / or housing structures in device 10, control circuit 20 can make adjustments to image data and / or other data processed by device 10 in response to data gathered using self-mixing sensor 70. For example, if measurements from sensor 70 indicate that display 14 has shifted to the left from its expected position, control circuit 20 can warp (shift, rotate, and / or shear) data for an image being displayed by display 14 to shift the image back to the right by a corresponding amount. In this way, detected misalignments of optical components can be corrected digitally (e.g., by processing captured image data from camera 46 and / or by processing image data supplied to display 14 to adjust the image for the measured misalignment).

[0074] As indicated by line 114, the operations of blocks 110 and 112 can be performed continuously (e.g., according to a schedule, in response to detecting a drop event, in response to user input, etc.). In this way, optical components in device 10 can remain in satisfactory alignment even if the position of these devices is affected by a drop event or other high-stress condition.

[0075] As described above, one aspect of the techniques relates to gathering and using information, such as information from input-output devices. The present disclosure contemplates that in some instances, data can be gathered that includes personal information 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, home addresses, data or records relating to a user’s health or level of fitness (e.g., vital signs measurements, medication information, exercise information), birth date, name, password, biometric information, or any other identifying or personal information.

[0076] The present disclosure recognizes that the use of such personal information in the present technology can yield a wealth of benefits to users. For example, personal information data can be used to deliver targeted content that is of greater interest to the user. Hence, use of such personal information data enables a user to plan a more controlled and therefore more satisfying life. Moreover, the present disclosure contemplates that the personal information data can be used to provide more relevant content, including advertisements and other content to the user.

[0077] 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, users should be able to access the personal information data that they provided to the entities and have it changed, updated or deleted upon request. By way of example, such users should be able to access and change or delete their personal information data by contacting the entity directly. Also, such users should be able to exercise their rights, access their personal information data, and change or delete their personal information data as it interacts with the entity’s services by way of automated systems. Further, the user communities should have the ability to personalise their preferences to control the collection, use, and / or disclosure of their personal information data.

[0078] Regardless of 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 opt-in or opt-out of the collection, use, and / or disclosure of personal information data. As another example, users can be provided with an option to not provide to the present technology their specific location during the use of the present technology. In yet another example, a user is provided with other options to limit the length of time data is kept, the types of data kept, and the circumstances under which the data is shared.

[0079] Further, 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 of personal information data. Risk can be minimized by limiting the collection of data and deleting data once it is no longer needed. In addition, and when applicable, data de-identification can be used to protect user privacy. To the extent

[0080] Thus, although the present disclosure broadly covers the implementation of one or more various disclosed embodiments using information that can include personal information data, the present disclosure also contemplates that the various embodiments can also be implemented using any other type of data or information.

[0081] Physical Environment: Physical environment refers to the physical world that people are able to sense and / or interact with without the need for electronic systems. A physical environment such as a physical park includes physical items such as physical trees, physical buildings, and physical people. People are able to directly sense and / or interact with the physical environment, such as through sight, touch, hearing, taste, and smell.

[0082] Computer-Generated Reality: 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 physical motions, or representations thereof, of a person 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 physical law. For example, a CGR system can detect a person’s head turning, and, in response, adjust graphical content presented to the person and an acoustic field in a manner that mimics how such views and sounds would change in a physical environment. In some situations (e.g., for reasons of accessibility), adjustments to characteristics of virtual objects in the CGR environment can be made in response to representations of physical motions (e.g., voice commands). People can sense and / or interact with CGR objects with any of their senses, including sight, hearing, touch, taste, and smell. For example, a person can sense and / or interact with an audio object that creates a 3D or spatial audio environment that provides a perception of point audio sources in a 3D space. As another example, an audio object can enable audio transparency that selectively incorporates ambient sound from a physical environment with or without computer-generated audio. In certain CGR environments, a person can sense and / or interact only with audio objects. Examples of CGR include virtual reality and mixed reality.

[0083] Virtual Reality: A virtual reality (VR) environment refers to a simulated environment designed to be completely based on computer-generated sensory inputs to one or more senses. A VR environment includes multiple virtual objects that a person can sense and / or interact with. For example, computer-generated images of trees, buildings, and avatars representing people are examples of virtual objects. A person can sense and / or interact with virtual objects in a VR environment through a simulation of the person's presence within the computer-generated environment and / or through a simulation of a subset of the person's physical movements within the computer-generated environment.

[0084] Mixed reality: In contrast to VR environments, which are 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 or representations thereof from a physical environment in addition to including computer-generated sensory inputs (e.g., virtual objects). On a virtuality continuum, a mixed reality environment is anywhere between a completely physical environment on one end and a virtual reality environment on the other end, but does not include either of the two extremes. In some MR environments, the computer-generated sensory inputs can be responsive to changes in the sensory inputs from the physical environment. Additionally, some electronic systems for presenting MR environments can track position and / or orientation relative to a physical environment to enable virtual objects to interact with real objects (i.e., physical articles from the physical environment or representations thereof). For example, a system can cause movement such that a virtual tree appears to be stationary relative to a physical ground. Examples of mixed reality 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 can have a transparent or translucent display through which a person can view the physical environment directly. The system can be configured to present virtual objects on the transparent or translucent display so that the person, using the system, perceives the virtual objects superimposed over the physical environment. Alternatively, a system can 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 combines the images or video with virtual objects and presents the combination on the opaque display. A person, using the system, views the physical environment indirectly via the images or video of the physical environment and perceives the virtual objects superimposed over the physical environment. As used herein, video of the physical environment displayed on an opaque display is referred to as “pass-through video,” meaning that the system uses one or more imaging sensors to capture images of the physical environment and uses those images in presenting the AR environment on the opaque display. Further alternatively, a system can have a projection system that projects virtual objects into the physical environment, e.g., as a holograph 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, the system can transform the one or more sensor images to impose a selected perspective (e.g., viewpoint) that is different from the perspective captured by the imaging sensors. As another example, a representation of a physical environment can be transformed by graphically modifying (e.g., enlarging) portions thereof so that the modified portions can be representative but not true versions of the originally captured images. As another example, a representation of a physical environment can be transformed by graphically eliminating or blurring portions thereof.Augmented Virtual: An augmented virtual (AV) environment refers to a simulated environment in which a virtual environment or computer-generated environment incorporates one or more sensory inputs from the physical environment. The sensory inputs can be representations of one or more characteristics of the physical environment. For example, an AV park can have virtual trees and virtual buildings, but people’s faces are realistically reproduced from images taken of physical people. As another example, virtual objects can take on the shape or color of physical items imaged by one or more imaging sensors. As another example, virtual objects can take on shadows consistent with the positioning of the sun in the physical environment.

[0085] 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 that integrate display capabilities, windows that integrate display capabilities, displays formed as lenses that are designed to be placed on a person’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, tablet computers, and desktop / laptop computers. A head-mounted system can have one or more speakers and an integrated opaque display. Alternatively, a head-mounted system can be configured to accept an external opaque display (e.g., a smartphone). A head-mounted system can 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. A head-mounted system can have a transparent or translucent display instead of an opaque display. A transparent or translucent display can have a medium through which light representative of an image is directed to a person’s eyes. The display can utilize digital light projection, OLEDs, LEDs, pLEDs, liquid crystal on silicon, laser scanning light source, or any combination of these technologies. The medium can be an optical waveguide, a hologram medium, an optical combiner, an optical reflector, or any combination thereof. In one embodiment, a transparent or translucent display can be configured to selectively become opaque. A projection-based system can employ retinal projection technology that projects graphical images onto a person’s retinas. Projection systems can also be configured to project virtual objects into the physical environment, for example, as a hologram or on a physical surface.

[0086] According to one embodiment, there is provided a head-mounted device comprising: a head-mounted housing; at least one optical module located in the head-mounted housing, the optical module having a display and having a lens configured to present images from the display to an eyebox; an optical self-mixing sensor configured to measure a distance to the lens; and an actuator configured to adjust the lens based on the measured distance.

[0087] According to another embodiment, the actuator is configured to move the lens in response to the measured distance.

[0088] According to another embodiment, the lens has a planar portion, and the optical self-mixing sensor is configured to emit a light beam that reflects from the planar portion back to the optical self-mixing sensor.

[0089] According to another embodiment, the optical module includes a lens barrel configured to support the lens, and the optical self-mixing sensor is configured to measure the distance to the lens by measuring a distance between the self-mixing sensor and the lens barrel.

[0090] According to another embodiment, the lens has a lens surface, and 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.

[0091] According to another embodiment, the self-mixing sensor includes a laser diode configured to emit light having a wavelength of 800-1100 nm.

[0092] According to another embodiment, the distance measured by the optical self-mixing sensor is a separation between the lens and the display.

[0093] According to another embodiment, the optical self-mixing sensor is configured to measure lateral movement of the lens relative to the optical self-mixing sensor independently of measuring a separation between the lens and the display.

[0094] According to one embodiment, there is provided a head-mounted device, comprising: a head-mounted housing; optical modules supported in the head-mounted housing, each optical module having a display and having a lens configured to present images from the display to a corresponding eyebox; an optical self-mixing sensor configured to measure a lens of a moveable optical module; and an actuator associated with a respective one of the optical modules and configured to move the lens of the optical module relative to the display of the optical module based on the lens measurement.

[0095] According to another embodiment, there are at least two of the optical self-mixing sensors for each of the lenses.

[0096] According to another embodiment, each optical module has an array of the optical self-mixing sensors.

[0097] According to another embodiment, each lens has a lens surface, and the array of optical self-mixing sensors in each optical module measures deformation of the lens surface in the optical module by measuring a distance between the optical self-mixing sensors in the array and the lens surface.

[0098] According to another embodiment, each optical self-mixing sensor has a laser that emits light and has a detector, each of the lenses has a lens surface, and the detectors of the optical self-mixing sensors are each configured to detect the emitted light after the emitted light from the optical self-mixing sensor has reflected from the lens surface.

[0099] According to another embodiment, the optical self-mixing sensors include at least a first optical self-mixing sensor, a second optical self-mixing sensor, and a third optical self-mixing sensor in each optical module.

[0100] According to another embodiment, the first optical self-mixing sensor of each optical module is configured to measure a distance between the first optical self-mixing sensor and the lens in the optical module.

[0101] According to another embodiment, the second optical self-mixing sensor and the third optical self-mixing sensor of each optical module are configured to measure a lateral shift of the lens relative to the second optical self-mixing sensor and the third optical self-mixing sensor.

[0102] According to one embodiment, a head-mounted device is provided, the head-mounted device comprising: a head-mounted support structure; an optical component supported by the head-mounted support structure; an optical self-mixing sensor configured to measure a distance to the optical component; and an actuator configured to move the optical component based at least in part on information from the optical self-mixing sensor.

[0103] According to another embodiment, the optical component comprises a lens.

[0104] According to another embodiment, the optical component comprises a camera.

[0105] According to another embodiment, the optical component has a surface, and the optical self-mixing sensor is configured to emit light that reflects from the surface, and is configured to receive the emitted light after the emitted light has reflected from the surface.

[0106] The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments can be implemented independently or in any combination.

Claims

1. 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 eyebox; optical self-mixing sensors configured to measure the lens of the optical module, 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 a deformation of the lens surface in that optical module by measuring a distance between the optical self-mixing sensors in 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 measurement.

2. The head-mounted device of claim 1, wherein there are at least two of the optical self-mixing sensors for each of the lenses.

3. The head-mounted device of claim 1, 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 after it has reflected from the lens surface.

4. The head-mounted device of claim 1, wherein the optical self-mixing sensors further comprise at least a first, a second, and a third optical self-mixing sensor in each optical module.

5. The head-mounted device of claim 4, wherein the first optical self-mixing sensor of each optical module is configured to measure a distance between the first optical self-mixing sensor and the lens in that optical module.

6. The head-mounted device of claim 5, wherein the second and third optical self-mixing sensors of each optical module are configured to measure a lateral shift of the lens relative to the second and third optical self-mixing sensors.

7. A head-mounted device comprising: a head-mounted support structure; a lens supported by the head-mounted support structure; an array of optical self-mixing sensors, wherein the lens has a lens surface, and wherein the array of optical self-mixing sensors measures a deformation of the lens surface by measuring a distance between the optical self-mixing sensors in the array and the lens surface; and an actuator configured to move the lens based at least in part on information from the array of optical self-mixing sensors.

8. The head-mounted device of claim 7, wherein each optical self-mixing sensor is configured to emit light that reflects from the lens surface and is configured to receive the emitted light after it has reflected from the lens surface.

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