Patent Description:
This relates generally to head-mounted devices.

Electronic devices have components such as displays. The positions of these components may sometimes be adjusted.

<CIT> discloses a head mounted display having a support structure, a display module displaying an image, a gaze tracker, a positioner adjusts the interpupillary distance measured by the gaze tracker.

<CIT> and <CIT> disclose head mounted displays.

<FIG> is a schematic diagram of an illustrative electronic device of the type that may include movable components. Device <NUM> of <FIG> is a head-mounted device (e.g., goggles, glasses, a helmet, and/or other head-mounted device), a cellular telephone, a tablet computer, a laptop computer, a wristwatch, a peripheral device (sometimes referred to as a peripheral) such as a pair of headphones, or other electronic equipment, where examples that are not head-mounted are not according to the claimed invention. According to the claimed invention, device <NUM> is a head-mounted device such as a pair of goggles (sometimes referred to as virtual reality goggles, mixed reality goggles, augmented reality glasses, etc.).

As shown in the illustrative top view of device <NUM> of <FIG>, device <NUM> has a housing such as housing <NUM> (sometimes referred to as a head-mounted support structure or head-mounted support). Housing <NUM> may include a main portion such as portion <NUM> (sometimes referred to as a main unit or head-mounted unit) and other head-mounted support structures such as head strap 12T. When housing <NUM> is being worn on the head of a user, the front of housing <NUM> may face outwardly away from the user, the rear of housing <NUM> may face towards the user, and the user's eyes may be located in eye boxes <NUM>.

Device <NUM> may have electrical and optical components that are used in displaying images to eye boxes <NUM> when device <NUM> is being worn. These components may include left and right optical assemblies <NUM> (sometimes referred to as optical modules). Each optical assembly <NUM> may have an optical assembly support <NUM> (sometimes referred to as a lens barrel or optical module support) and guide rails <NUM> along which optical assemblies <NUM> may slide to adjust optical-assembly-to-optical-assembly separation to accommodate different user interpupillary distances.

Each assembly <NUM> may have a display <NUM> that has an array of pixels for displaying images and a lens <NUM>. Display <NUM> and lens <NUM> of each assembly <NUM> may be coupled to and supported by support <NUM>. During operation, images displayed by displays <NUM> may be presented to eye boxes <NUM> through lenses <NUM> for viewing by a user. Each optical assembly <NUM> may also have a gaze tracker <NUM>. Gaze trackers <NUM> may each include one or more light sources (e.g., infrared light-emitting diodes that provide flood illumination and glints for eye tracking) and an associated camera (e.g., an infrared camera). Using gaze trackers <NUM>, which may sometimes be referred to as gaze tracking systems or gaze tracking sensors, device <NUM> can gather data on a user's eyes located in eye boxes <NUM>. As an example, the direction in which a user's eyes are pointing (sometimes referred to as a user's point of gaze or direction of view) may be measured. Biometric information such as iris scan information may also be gathered. In addition, gaze trackers <NUM>, may be used to measure the location of a user's eyes relative to device <NUM> and thereby measure the eye relief of the user's eyes (e.g., the distance between the lenses of device <NUM> and the eyes) and the separation between the user's left and right eyes (sometimes referred to as the user's interpupillary distance). If desired, gaze trackers <NUM> (e.g., the cameras of trackers <NUM>) may capture images of the skin of the user's face surrounding the user's eyes (e.g., to measure whether this skin is loose or taut).

Each optical assembly may have magnets, clips, and/or other engagement features to allow removable vision correction lenses (sometimes referred to as prescription lenses) to be removably attached to assemblies <NUM> in alignment with lenses <NUM> (see, e.g., illustrative optional vision correction lenses <NUM>). Lenses <NUM> may have magnets that are sensed by sensors <NUM> (e.g., magnetic sensors in assemblies <NUM>) or sensors <NUM> may be optical sensors, switches, or other sensors configured to gather other information indicating when lenses <NUM> are present.

Housing <NUM> may have a flexible curtain (sometimes referred to as a flexible rear housing wall or fabric housing wall) such as curtain 12R on the rear of device <NUM> facing eye boxes <NUM>. Curtain 12R has openings that receive assemblies <NUM>. The edges of curtain 12R that surround each support <NUM> may be coupled to that support <NUM>. The outer peripheral edge of curtain 12R may be attached to rigid housing walls forming an outer shell portion of main housing <NUM>.

The walls of housing <NUM> may separate interior region <NUM> within device <NUM> from exterior region <NUM> surrounding device <NUM>.

Inner ends <NUM> of guide rails <NUM> may be attached to central housing portion 12C. Opposing outer ends <NUM> may, in an illustrative configuration, be unsupported (e.g., the outer end portions of rails <NUM> may not directly contact housing <NUM>, so that these ends float in interior region <NUM> with respect to housing <NUM>).

Device <NUM> may include control circuitry and other components such as component <NUM>. The control circuitry may include storage, processing circuitry formed from one or more microprocessors and/or other circuits. To support communications between device <NUM> and external equipment, the control circuitry may include wireless communications circuitry. Components <NUM> may include sensors such as such as 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, optical sensors such as optical sensors that emit and detect light, ultrasonic sensors, and/or other touch sensors and/or proximity sensors, monochromatic and color ambient light sensors, image sensors, sensors for detecting position, orientation, and/or motion (e.g., accelerometers, magnetic sensors such as compass sensors, gyroscopes, and/or sensors such as inertial measurement units that contain some or all of these sensors), radio-frequency sensors, depth sensors (e.g., structured light sensors and/or depth sensors based on stereo imaging devices), optical sensors such as self-mixing sensors and light detection and ranging (lidar) sensors that gather time-of-flight measurements, humidity sensors, moisture sensors, visual inertial odometry sensors, gaze tracking sensors, and/or other sensors. In some arrangements, devices <NUM> may use sensors to gather user input (e.g., button press input, touch input, etc.). Sensors may also be used in gathering environmental motion (e.g., device motion measurements, temperature measurements, ambient light readings, etc.) and/or may be used in measuring user activities and/or attributes (e.g., point-of-gaze, eye relief, interpupillary distance, etc.). If desired, position sensors such as encoders (e.g., optical encoders, magnetic encoders, etc.) may measure the position and therefore the movement (e.g., the velocity, acceleration, etc.) of optical assemblies <NUM> along rails <NUM>.

<FIG> is a rear view of an illustrative portion of device <NUM> (e.g., an inside left portion). Device <NUM> may have left and right actuators (e.g., motors) such as motor <NUM> that are used to rotate an elongated threaded shaft such as screw <NUM>. Nut <NUM> has threads that engage the threads on screw <NUM>. As the motor <NUM> on each side of device <NUM> is turned, a corresponding nut <NUM> is driven in the +X or -X direction (in accordance with whether screw <NUM> is being rotated clockwise or counterclockwise). In turn, this moves the optical assembly <NUM> on that side of device <NUM> in the +X or -X direction along its optical assembly guide rail <NUM>. If desired, the left and right motors <NUM> may be adjusted independently, so that optical assemblies <NUM> on the left and right of device <NUM> may be moved independently.

Each assembly <NUM> (e.g., each support <NUM> of <FIG>) may have portions that receive a corresponding rail <NUM> and that guide that assembly <NUM> along that rail <NUM>. By controlling the activity of motors <NUM> in tandem or individually, the spacing between the left and right optical assemblies of device <NUM> can be adjusted to accommodate the interpupillary distance of different users. For example, if gaze trackers <NUM> determine that a user has closely spaced eyes, assemblies <NUM> may be moved inwardly (towards each other) and if a user has widely spaced eyes, assemblies <NUM> may be moved outwardly (away from each other). By matching the spacing between optical assemblies <NUM> to the measured interpupillary distance of a user, the user may satisfactorily view visual content being presented by the displays of the optical assemblies.

The position and therefore the movement of each optical assembly may be monitored using one or more sensors. In the illustrative configuration of <FIG>, motor <NUM> (e.g., the motor on the left side of device <NUM>) and optical module <NUM> have been provided with an optical assembly position sensor based on a magnetic encoder. The encoder includes magnetic strip <NUM> and magnetic sensor <NUM>. Magnetic sensor <NUM> may be a Hall Effect sensor or other suitable magnetic sensor that is configured to move with optical assembly <NUM>. Magnetic strip <NUM>, which may be affixed to housing <NUM>, has a series of magnet poles (e.g., north and south poles) that extend along the X dimension parallel to guide rail <NUM> and parallel to the X-axis position adjustment direction associated with optical assembly <NUM>. As optical assembly <NUM> is moved along guide rail <NUM>, the magnetic encoder (e.g., sensor <NUM>) measures the change in magnetic field resulting as magnetic sensor <NUM> passes by different magnets in strip <NUM>. In this way, optical assembly <NUM> is provided with a position reference (e.g., by counting north and south magnetic poles in strip <NUM>). The position measurements made with the position sensor may reveal attributes of the motion of optical assembly <NUM> such as the velocity of optical assembly <NUM> and, if desired, the acceleration and deceleration of assembly <NUM>. Accordingly, the magnetic encoder (or other position sensor) associated with each optical assembly <NUM> may be used by device <NUM> to measure the location of that optical assembly so that the spacing between optical assemblies <NUM> can be satisfactorily adjusted (e.g., to help ensure that the spacing between optical assemblies <NUM> has been adjusted to match or nearly match the user's interpupillary distance). The position readings from the optical assembly position sensors (e.g., the magnetic encoders) may also be used to determine the velocities of the optical assemblies as they are moved.

Optical assembly velocity information and/or other information from the optical assembly position sensors (e.g., linear position sensors formed from the magnetic encoders) may be used in monitoring whether the optical assemblies have slowed down their movement due to contact between the optical assemblies and the nose of a user. Consider, as an example, the arrangement of <FIG> is a rear view of a central nose-bridge portion NB of device <NUM>. As shown in <FIG>, nose bridge portion NB of housing portion 12C has a nose-shaped recess <NUM>, which is configured to receive the user's nose (see, e.g., illustrative nose surface <NUM>). In some situations (e.g., when a user has a wide interpupillary distance), optical assemblies <NUM> reside at a non-zero distance G from surface <NUM> (sometimes referred to as gap G) after motors <NUM> adjusted the positions of assemblies <NUM> to match the user's interpupillary distance. In other situations, such as when a user has a large eye relief and small interpupillary distance, motors <NUM> may move optical assemblies inward until curtain 12R (<FIG>) and optical assemblies <NUM> contact the left and right sides of nose surface <NUM>.

When optical assemblies <NUM> contact the left and right sides of nose surface of <NUM>, motors <NUM> will encounter resistance to further lateral movement of the optical assemblies along the X axis. This will cause optical assemblies <NUM> to move more slowly. The optical assembly position sensors will sense the reduction in the velocity of the optical assemblies. In this way, device <NUM> is informed that optical assemblies <NUM> are contacting and pressing against nose surface <NUM>. To ensure that device <NUM> is comfortable as device <NUM> is being worn on the head of the user, the position of the optical assemblies may, in response to this detected nose contact, be adjusted outward, away from nose surface <NUM> (e.g., by <NUM>-<NUM> or other suitable amount). This outward nudge in the positions of the optical assemblies may be made even if the final separation between the optical assemblies is slightly larger than the user's measured interpupillary distance.

Following outward adjustment of optical assemblies <NUM>, a non-zero gap G may be created between optical assemblies <NUM> and corresponding side portions of the user's nose (e.g., adjacent portions of nose surface <NUM>) and/or inward pressure imposed on the sides of the user's nose by optical assemblies <NUM> can be reduced to enhance comfort. By monitoring the optical assembly position sensors during optical assembly position adjustment with motors <NUM>, device <NUM> can identify a location for assemblies <NUM> in which the left and right assemblies <NUM> are separated by distance that is matched as closely as possible to the user's measured interpupillary distance while ensuring satisfactory comfort for the user.

According to the invention, the position of optical assemblies <NUM> can be adjusted satisfactorily involves the use of eye relief measurements from gaze trackers <NUM>. When device <NUM> is placed onto the head of the user, gaze trackers <NUM> may measure the user's interpupillary distance and may measure the user's eye relief. Motors <NUM> may then adjust the positions of optical assemblies <NUM> based on the measured eye relief and measured interpupillary distance of the user. In an illustrative configuration, the positions of optical assemblies <NUM> maybe offset (e.g., nudged outwards from the location where the spacing between assemblies <NUM> matches the measured interpupillary distance of the user) by an amount that varies depending on both measured interpupillary distance and measured eye relief.

This type of approach is illustrated in the graph of <FIG>. In the graph of <FIG>, lateral offset ΔX represents the distance by which an optical assembly is adjusted outwardly (beyond the nominal position in which optical assembly separation matches measured interpupillary distance) to enhance fit. There are three illustrative curves in the graph of <FIG>. Curve <NUM> corresponds to a measured interpupillary distance IPDA, curve <NUM> corresponds to a measured interpupillary distance IPDB, which is larger than interpupillary distance IPDA, and curve <NUM> corresponds to a measured interpupillary distance IPDC, which is larger than interpupillary distance IPDA and larger than interpupillary distance IPDB. The values of IPDA, IPDB, and IPDC may be in the range of <NUM> to <NUM> or any other suitable range. In practice, device <NUM> may store a family of curves (e.g., empirically determined curves) for any suitable number of measured interpupillary distances and/or may represent the relationships embodied in curves such as curves <NUM>, <NUM>, and <NUM> using tables, functions, and/or other data structures.

As the graph of a <FIG> illustrates, if the measured eye relief of a user falls below a predetermined threshold (e.g., ERTH in the example of <FIG>), the user is unlikely to experience pressure from optical assemblies <NUM> on the sides of the user's nose. Accordingly, for measured user eye relief values below eye relief threshold ERTH, optical assemblies <NUM> may be separated along the X axis by a distance that matches the measured interpupillary distance of the user (e.g., there is no need to use a non-zero value of ΔX to adjust the position of optical assemblies <NUM> outwardly after they have reached the appropriate spacing to match the user's interpupillary distance). The value of ΔX is therefore zero for users with measured eye relief values of less than ERTH (which may be, for example, a value between <NUM> and <NUM> or other suitable eye relief threshold value).

If, however, the measured eye relief of a user exceeds eye relief threshold ERTH, it may be beneficial for certain users to increase the spacing between optical assemblies <NUM> by nudging each optical assembly outwardly by an amount ΔX. As an example, consider users with measured interpupillary distances of IPDA. For this class of user, it may be beneficial to adjust the spacing of optical assemblies <NUM> outwardly by ΔX values that follow curve <NUM>. As shown by curve <NUM>, ΔX may be zero for measured eye relief values of less than ERTH, whereas for measured eye relief values exceeding ERTH, ΔX may rise progressively as a function of measured eye relief (e.g., up to a maximum ΔX value at a maximum measured eye relief value of ERMX, which may be, for example, <NUM> or other suitable value). Users with larger interpupillary distances, such as a measured interpupillary distance of IPDB, may benefit from a less aggressive outward increase in optical assembly spacing, as shown by curve <NUM> in which the value of ΔX rises more slowly as a function of increasing measured eye relief over ERTH than curve <NUM>.

An interpupillary distance threshold may be present above which it may not be desirable to make any ΔX adjustments for a user, regardless of their measured eye relief. When, for example, a user has a large measured interpupillary distance (e.g., a measured interpupillary distance of IPDC, which exceeds the interpupillary distance threshold), there will generally not be a comfort benefit in increasing optical assembly spacing. As a result, the recommended outward adjustment in optical assembly position ΔX as a function of measured eye relief for users with these larger measured interpupillary distances follows curve <NUM> (e.g., ΔX remains at zero, even for a measured eye relief of ERMX). With this approach, only at measured interpupillary distances below the interpupillary distance threshold will outward adjustments in optical assembly position be used.

The graph of <FIG> illustrates how motors <NUM> may place optical assemblies <NUM> at positions that vary from the measured positions of the user's eyes. In the example of <FIG>, measured eye relief and interpupillary distance values were used in determining satisfactory positions for assemblies <NUM>. In particular, outward adjustments ΔX in the positions of optical assemblies <NUM> were recommended as a function of the interpupillary distance and eye relief values measured for a user with gaze trackers <NUM>. If desired, additional factors may be taken into consideration in making optical assembly adjustments such as these (e.g., additional factors that may be used in combination with or as an alternative to using interpupillary distance measurements and eye relief measurements) and/or other suitable action may be taken based on data gathered with gaze trackers <NUM> and/or other sensors in device <NUM>.

<FIG> is a flow chart illustrating operations involved in using motors <NUM> and other components in device <NUM> to make adjustments to device <NUM> as a function of data gathered with gaze trackers <NUM> and/or other sensors.

During the operations of block <NUM>, device <NUM> may gather data. The gathered data may include, for example, measurements obtained by gaze trackers <NUM>. These measurements include the measured interpupillary distance of a user wearing device <NUM>, the measured eye relief of a user wearing device <NUM>, and may include, for example, the measured skin tautness around the eyes of a user wearing device <NUM>, and/or other gaze tracker measurements. The measurements of block <NUM> may also include measurements with the position sensors (e.g., the magnetic encoders) of optical assemblies <NUM>. For example, when a user dons device <NUM>, motors <NUM> may automatically start to move optical assemblies <NUM> to positions associated with the user's measured interpupillary distance from gaze trackers <NUM>. During this initial movement or during movement in response to a user input command or other movement, the position sensors may be used to monitor the velocities of assemblies <NUM>. In response to detected slowing of the speed of inward movement of assemblies <NUM>, device <NUM> can conclude that assemblies <NUM> are beginning to exert pressure on the sides of the user's nose (e.g., nose surface <NUM>). The locations associated with the measured reduction in optical assembly velocity are another form of measurement data that may be gathered during block <NUM>.

Further information that can be gathered during the operations of block <NUM> relates to the status of vision correction lenses <NUM> on device <NUM>. Vision correction lenses <NUM> may contain magnets that produce a magnetic field. Device <NUM> (e.g., assemblies <NUM>) may have vision correction lens sensors such as magnetic sensors <NUM> that determine whether or not lenses <NUM> are present by monitoring for the presence of the magnetic fields produced by lenses <NUM>. In response to detection of the magnetic fields from lenses <NUM> with sensors <NUM>, it can be concluded that lenses <NUM> are present.

During the operations of block <NUM>, device <NUM> can take action based on the data gathered at block <NUM>. As an example, the positions of optical assemblies <NUM> may be adjusted using motors <NUM>. In some configurations, the positions of optical assemblies <NUM> may be nudged outwards by an amount ΔX determined from measured interpupillary distance and eye relief values, as described in connection with <FIG>. If desired, optical assemblies <NUM> may, in some scenarios, be moved inward slightly (e.g., assemblies <NUM> may be moved towards each other such that assemblies <NUM> are closer than dictated by the measured value of a user's interpupillary distance to increase nasal field-of-view overlap when doing so presents a low risk of optical assembly nose surface contact or when any potential nose contact can be detected with an optical module position sensor or other sensor). To reduce wrinkles in rear curtain 12R, optical assemblies <NUM> may be moved inwards or outwards slightly to tighten curtain 12R. Optical assembly movement with motors <NUM> may also be used to provide a user with an alert (e.g., a haptic alert indicating that an incoming message has been received and/or another condition has been determined to be present). In some arrangements, gaze sensor measurements from trackers <NUM> during block <NUM> can be used to determine whether the user's skin surrounding the user's eyes is taut. In response to detecting an increase in skin tautness as assemblies <NUM> are moved (e.g., as assemblies <NUM> are being moved towards each other), it can be concluded that assemblies <NUM> are pressing or are about to press on nose surface <NUM>, so further movement inward of assemblies <NUM> can be halted and/or assemblies <NUM> may be nudged outwardly to compensate. The positions of optical assemblies <NUM> may also be adjusted in response to detection that vision correction lenses <NUM> are present or are not present. The presence of lenses <NUM> may, as an example, increase or decrease the risk of nose contact by assemblies <NUM>, so information on the presence of lenses <NUM> (and, if desired, the prescription associated with lenses <NUM>) may be taken into account when using motors <NUM> to adjust the position of assemblies <NUM>. In general, these types of adjustments and/or other suitable actions may be taken during the operations of block <NUM> in response to gaze tracker measurement data and/or other data measured during the operations of block <NUM>.

To help protect the privacy of users, any personal user information that is gathered by sensors may be handled using best practices. These best practices including meeting or exceeding any privacy regulations that are applicable. Opt-in and opt-out options and/or other options may be provided that allow users to control usage of their personal data.

In accordance with the invention, a head-mounted device is provided that includes a head-mounted housing, an optical assembly in the head-mounted housing that is configured to provide an image to an eye box, a gaze tracker and a motor configured to position the optical assembly based on a measured eye relief from the gaze tracker and a measured interpupillary distance from the gaze tracker.

Preferably, the motor is configured to move the optical assembly outward from a central portion of the head-mounted housing in response to determining that the measured eye relief is more than a predetermined threshold amount.

Preferably, the motor is configured to adjust the position of the optical assembly outwards by a first amount in response to determining that the measured eye relief has an eye relief value that is more than a predetermined threshold amount and that the measured interpupillary distance has a first value and is configured to move the optical assembly outwards by a second amount that is more than the first amount in response to determining that the measured eye relief has the eye relief value and that the measured interpupillary distance has a second value that is less than the first value.

Preferably, the head-mounted device includes a vision correction lens sensor, the motor is further configured to position the optical assembly based on information from the vision correction lens sensor.

Preferably, the optical assembly is configured to receive a removable vision correction lens with a magnet that produces a magnetic field and the motor is further configured to position the optical assembly based on information from the magnetic sensor.

Preferably, the motor is configured to provide a haptic alert by moving the optical assembly.

Preferably, the gaze tracker is configured to measure skin tautness.

Preferably, the motor is further configured to adjust the position of the optical assembly based on the measured skin tautness.

Claim 1:
A head-mounted device (<NUM>), comprising:
a head-mounted housing (<NUM>);
an optical assembly (<NUM>) in the head-mounted housing that is configured to provide an image to an eye box (<NUM>);
a gaze tracker (<NUM>); and
a motor (<NUM>) configured to position the optical assembly (<NUM>) based on a measured eye relief from the gaze tracker (<NUM>) and a measured interpupillary distance from the gaze tracker (<NUM>).