Head attribute detection in display-enabled wearable device

Abstract

A display-enabled eye-worn device has an integrated head sensor that dynamically and continuously measures or detects various head parameters of the wearer's head. The head sensor includes a loop coupler system integrated in a lens-bearing frame to sense RF absorption of a nearby environment affected by the presence, size, and / or distance of the head. Autonomous device management dynamically adjusts or causes adjustment of selected device features based on current detected values of head parameters, which may include wear status, head size, and frame-head spacing.

Description

[0001] Priority Claim

[0002] This application claims the benefit of priority to U.S. Patent Application No. 17 / 968,289, filed on October 18, 2022, which is hereby incorporated by reference in its entirety. Background Art

[0003] Head-mounted augmented reality (AR) devices (e.g., AR-enabled ocular head-mounted devices) are typically implemented with near-eye displays carried by transparent or translucent lens assemblies through which the wearer can view the surrounding environment ("real world"). Such near-eye displays are typically themselves partially transparent such that objects presented by the near-eye display (e.g., virtual objects such as 3D renderings, images, videos, text, etc.) appear to the wearer as if superimposed over their real-world surrounding environment. AR displays in such devices are typically stereoscopic, producing an illusion of depth and / or 3D position in the environment by presenting two slightly different images to the wearer's right and left eyes.

[0004] This is commonly referred to as "augmented reality", which is distinguished from the experience commonly referred to as "virtual reality" or VR provided by head-mounted devices that completely occlude the wearer's field of view and display a virtual environment in which the wearer can appear to move or be moved. As used herein, the term "augmented reality" or "AR" refers to augmented reality and virtual reality as traditionally understood, unless the context indicates otherwise.

[0005] In some examples, the AR device takes the form of AR glasses, which are ocular head-mounted devices (commonly referred to as smart glasses) configured to be worn conventionally in the manner of corrective glasses or sunglasses. As is the case with conventional non-smart ocular head-mounted devices, a pair of AR glasses typically has a lens system provided by a left lens assembly and a right lens assembly through which the surrounding environment is viewed during wear, where the near-eye AR display is typically natively integrated in the glasses to present visual images in the lens system or a corresponding display area in the lens system. Some examples of such near-eye displays include waveguides incorporated into the lens assemblies to receive light beams from projectors, but in other cases various different suitable display mechanisms have been used.

[0006] Near-eye displays, such as those commonly found in smart glasses that provide an AR experience, are inherently sensitive to the position of the wearer's eyes. For example, the size of the gap between the near-eye display and the eye during wear is preferably within a particular relatively small range such that the display can be properly focused for the wearer. However, in practice, this eye-display spacing can vary widely due to user preference or other factors, hindering the effective provision of AR display elements.

[0007] Another variable that affects the subjective quality and accuracy of near-eye displays is the variation in the lateral distance between the wearer's eyes. Providing a display area large enough to accommodate the typical range of eye spacings can result in excess or out-of-range portions in the displays for some users. Additional complexity applies to stereoscopic displays, i.e., the depth illusion created by such displays inherently depends on eye position, which can vary significantly among users with widely different head sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the drawings, which are not necessarily to scale, like reference numerals may describe like components in different views. To easily identify the discussion of any particular element or action, one or more of the most significant digits in the reference numeral refer to the figure number in which the element was first introduced. Some non-limiting examples are shown in the figures of the drawings, in which:

[0009] Figure 1 is a schematic three-dimensional view of a head-mounted device in the form of an example AR-enabled ocular wearable device, which is smart glasses with native AR capabilities.

[0010] Figure 2 shows a wearer's perspective view of an AR glasses corresponding to Figure 1 in accordance with one example.

[0011] Figure 3 is a block diagram of a networked system of a wearable AR device including a wearable AR device such as Figure 1 in accordance with one example.

[0012] Figure 4 is a graphical representation of a networked environment in which the present disclosure may be deployed in accordance with some examples.

[0013] Figure 5 shows a method 500 in accordance with one embodiment.

[0014] Figure 6 is a diagram showing, in accordance with one example, a method for detecting association with Figure 1one or more attributes of the head of a wearer of an AR glasses consistent with an example and a low-level flowchart of a method for responsive autonomous device management.

[0015] Figure 7 is according to an example of wearing and Figure 1 and Figure 2 a schematic top view of a user of AR glasses consistent with an example.

[0016] Figure 8 shows a forward transmission scattering parameter frequency distribution graph carried out by a head sensor loop coupler system incorporated in AR glasses consistent with the AR glasses of Figures 1 to 7 according to an example, the graph depicts multiple different curves for different corresponding simulations, where the only variable between the simulations is the size of the frame gap between the frame carrying the lenses of the AR glasses and the face of its wearer.

[0017] Figure 9 is a graph according to an example similar to Figure 8 which depicts multiple different curves for different corresponding simulations, where the only variable between the simulations is the head size of the wearer of the AR glasses.

[0018] Figure 10 is a graphical representation of a machine in the form of a computer system within which a set of instructions can be executed to cause the machine to perform any one or more of the methods discussed herein.

[0019] Figure 11 is a block diagram showing a software architecture in which an example can be implemented.

[0020] One aspect of the present disclosure provides techniques and mechanisms for measuring or detecting multiple attributes or parameters (sometimes also referred to as head parameters) of the head of a wearer of a device (e.g., display-enabled glasses or AR glasses) through the operation of an integrated head sensor in a wearable optical device. In some examples, the present disclosure also provides for autonomously performing device management actions to dynamically adjust or prompt the user to adjust selected device features based on detected values of head parameters provided by the head sensor.

[0021] As used herein, a wearer of a device is a user (if any) who is currently (i.e., at the relevant time described) wearing the relevant device. Example head parameters detectable by using a head sensor include head size, the distance between the head and the device (referred to as the frame gap in some examples), and the presence or absence of the head near the device (and thus dynamically detecting active wearing or non-wearing of the device).

[0022] It will be understood that some functions or systems of, for example, AR glasses are affected by changes in the value of one or more of the head parameters. Thus, in various examples, autonomous device management actions are provided for such head-affected functions or features. Thus, for example, the optimal near-eye display positioning changes with changes in the width spacing between the wearer's eyes. Some examples provide automatic display position adjustment based on the detected head size. In such cases, the head size is used as a measured head parameter that is roughly related to the eye spacing.

[0023] Alternatively or additionally, in some examples, the autonomous action includes communicating to the wearer a cue to adjust the frame gap to a target position / range that is optimal for viewing the near-eye display of the device, based on the detection of the current frame gap value. Alternatively or additionally, in some examples, the autonomous device automatically cuts off the power of at least some of the energized components when no head presence is detected (i.e., when the device is not currently being worn), and / or automatically activates the integrated display in response to detecting a head presence consistent with effective wearing.

[0024] The disclosed head sensor is configured to detect and measure the environmental absorption of radio frequency (RF) signals near the eye-worn device at different respective frequencies within a preset target frequency band, and process the measured RF absorption data based on the characteristic RF absorption of a reference human head to estimate the current value of one or more head parameters.

[0025] In some examples, the head sensor includes a loop coupler system that includes a pair of coupler loops connected to a transceiver device to transmit a known feed signal via one of the loops and read the sympathetically induced response signal via the other loop. The RF absorption characteristics of the nearby environment are determined by determining the amplitude or intensity difference between the feed signal and the response signal at the corresponding frequencies at multiple frequencies within the target frequency band. A relatively high signal loss at a particular frequency indicates a higher RF absorption rate at that frequency.

[0026] In some examples, the head size is based on identifying the frequency at which the forward transmission loss is the greatest. This mechanism is based on the insight that the frequency of maximum RF absorption changes with changes in head size, particularly with changes in head width, which is the head dimension that most accurately indicates the eye width spacing.

[0027] Alternatively or additionally, the device-head spacing (e.g., frame gap) is estimated based on the amplitude value of the response signal at the frequency of maximum loss. This mechanism is based on the insight that a decrease in the frame gap results in a greater forward transmission loss, and vice versa.

[0028] Alternatively or additionally, the head parameters detected by the head sensor include the wearing status, e.g., whether the device is currently worn on the head. In some examples, the wearing status is determined by determining whether the response signal at any frequency drops below a preset threshold. The absence of such an amplitude value below the threshold for the response signal indicates that there is no human head near the device.

[0029] Thus, it will be seen that in some aspects, the techniques described herein relate to a device comprising:

[0030] A device body configured to be supported on the head of a wearer of the device in use; a head sensor comprising:

[0031] A feed conductor accommodated by the device body;

[0032] A response conductor accommodated by the device body at a position spaced apart from the feed conductor; and

[0033] A transceiver device coupled to the feed conductor and the response conductor, the transceiver

[0034] being configured to perform operations including:

[0035] Transmitting an RF feed signal via the feed conductor; and

[0036] Reading a response signal induced by the feed signal in the response conductor; and

[0037] One or more computer processor devices forming part of the on-board electronics and configured to perform operations including:

[0038] Performing a signal processing procedure to derive a current value of a head-affected metric at least in part based on a comparison between the feed signal and the response signal, the head-affected metric being variable in use as a factor of the head parameters of a wearer with the device worn on the head; and identifying and implementing device management actions related to the head parameters.

[0039] In some examples, the device is an eye-wearable device (e.g., a display-enabled smart glasses or AR glasses), and further includes a loop coupler system that provides a feed conductor and a response conductor in the form of paired coupler loops. The loop coupler system includes: a feed loop driven by a transceiver device to transmit a feed signal; and a response loop coupled to the transceiver device to receive a response signal, the response loop being inductively coupled to the feed loop. In such an example, the device body includes an eye-wearable device frame that bears lenses, and the coupler loops are accommodated by the eye-wearable device frame such that each of the coupler loops is located in a respective operating upright plane oriented transversely to the operating viewing direction of the device.

[0040] In some examples, the eye-wearable device frame holds a pair of lenses spaced laterally apart, and each of the coupler loops extends peripherally around a respective one of the pair of lenses, and each coupler loop is substantially coplanar with the respective lens. In some such examples, each coupler loop is provided by a respective metal ring that extends around the associated lens. In some examples, one or both of the coupler loop lens rings serve as unlockable lens retainers that are held constrained within respective lens rims and, when locked, thereby impede removal of the respective lens from its lens rim. In additional embodiments, one or both of such coupler loop lens rings are additionally connected to an antenna system and form part of the antenna system for transceiving wireless communication signals, providing Bluetooth or WiFi antenna functionality in some examples.

[0041] In some examples, the on-board electronics are configured to perform a signal processing procedure based at least in part on analyzing a parameter indicative of a comparative forward transmission efficiency within a spectral range that spans a target frequency band of RF frequencies that are associated with absorption characteristics of the human head. In other words, the signal processing identifies the respective degree of signal loss or RF absorption at each of a plurality of different frequencies that span RF frequencies that are typically associated with head absorption.

[0042] In some examples, one or more head parameters determined by a head sensor include a wear state that indicates whether the eye-wearable device is currently being worn. In some such examples, the applicable head-affected metrics of the head parameters from which the wear state is derived are based on or related to the following: the minimum response signal amplitude value or the maximum loss feed-response coupling within the spectral range of the signal. In some such examples, the on-board electronics are configured to derive the wear state by operations that include: (a) determining that the device is currently being worn in the case where it is recognized that the feed-response coupling at a frequency within the target frequency band drops below a predefined threshold; and (b) determining that the device is currently not being worn in the case where the feed-response coupling is above the threshold in intensity within the spectral range.

[0043] In such examples, in some cases, the device management actions include: automatically activating the near-eye display in response to determining that the device is currently being worn when the integrated near-eye display of the eye-wearable device is deactivated. Alternatively or additionally, in some examples, the device management actions triggered by the wear state include automatically cutting off the power of at least some of the on-board electronics and / or systems in response to determining an unworn state.

[0044] Alternatively or additionally, in some examples, one or more head parameters detected via a head sensor include a frame gap, which is defined by a lateral spacing in the viewing direction between the eye-wearable device frame and the wearer's head. In the case of, for example, AR glasses, the frame gap value typically corresponds to or indicates how far the integrated near-eye display is from the wearer's eyes. In some such examples, the applicable head-affected metric of the head parameter from which the wear gap is derived is based on or related to the following: the magnitude of the response signal amplitude (or conversely, the degree of feed-response signal loss) at the frequency of maximum loss (which is the specific frequency in the signal spectral range where the feed-response coupling is weakest). Thus, in some examples, the on-board electronics are configured to derive a head-affected metric indicating the current frame gap value by a process that at least partially includes determining the response signal amplitude at the frequency of maximum loss within a target frequency band, thereby identifying the minimum amplitude of the response signal within the target frequency band. In some such examples, the associated device management actions include: (a) determining that the minimum amplitude exceeds a threshold of a predefined target frame gap that is conducive to achieving visual clarity of the near-eye display incorporated in the eye-wearable device from the wearer's perspective; and (b) automatically communicating an adjustment prompt to the wearer to change the lateral spacing between the eye-wearable device frame and the wearer's head.

[0045] Alternatively or additionally, in some examples, one or more head parameters detected via a head sensor include head dimensions that quantify one or more dimensions of a wearer's head. In some examples, a head dimension parameter indicates the width of the wearer's head or the width of the face. In some such examples, an applicable head-affected metric of the head parameter from which the head dimension is derived is based on or related to the following: the frequency value of the frequency at which the loss of the feed signal is greatest within its spectral range. Thus, in some examples, the current value of the head-affected metric is derived in a process that at least partially includes the following operations: (a) identifying the frequency of greatest loss, which is the frequency at which the signal loss between the feed loop and the response loop is greatest within a target frequency band; and (b) estimating the current head dimension value based on the frequency of greatest loss of the response signal. In some such examples, estimating the current head dimension value includes a look-up operation that uses the frequency of greatest loss as a reference value to query look-up data (e.g., a look-up table) that includes a plurality of values of the frequency of greatest loss associated with different respective head dimension values.

[0046] In some such examples, an autonomous response device management action includes adjusting the display position of a near-eye display based on the wearer's head dimensions (which thereby serves as a proxy for eye position). In some examples, such a display adjustment includes: (a) identifying, based on the current head dimension value, a particular sub-part of the available display area provided by an integrated near-eye display for activation; and (b) autonomously activating the particular sub-part of the available display area of the near-eye display, thereby adjusting the display position of the near-eye display based on the wearer's head dimensions.

[0047] In some aspects, the techniques described herein relate to a method that includes: (a) transmitting an RF feed signal using a feed conductor incorporated into a head-mounted device; (b) reading a response signal induced by the feed signal in a response conductor incorporated into the device; (c) performing, in an automated operation performed by on-board electronics, a signal processing procedure to derive a current value of a head-affected metric at least partially based on a comparison between the feed signal and the response signal, the head-affected metric being variable as a factor of a head parameter related to the head of a wearer currently wearing the device, wherein the on-board electronics are housed by the device and include one or more computer processor devices; and (d) identifying and implementing a device management action related to the head parameter in an autonomous operation performed by the on-board electronics at least partially based on the current value of the head-affected metric. Different examples of such a method include the example variations and features mentioned above with reference to the device-related aspects of the disclosed techniques.

[0048] In some examples, the device is an eye-wearable device, the eye-wearable device including an eye-wearable device frame that bears a lens; wherein, the device further includes a loop coupler system having a pair of coupler loops that serve as a feed conductor and a response conductor respectively, each coupler loop extending circumferentially around an associated lens held by the eye-wearable device frame; and wherein, the signal processing procedure is at least partially based on analyzing a change in feed-response coupling within a spectral range that spans a target frequency band of RF frequencies that are associated with absorption characteristics of a human head.

[0049] In some examples, the method further includes identifying a wearing state of the eye-wearable device, the wearing state indicating whether the eye-wearable device is currently being worn, and identifying the wearing state includes: (a) determining whether a feed-response coupling efficiency drops below a predefined threshold for any frequency within the target frequency band; (b) in the case where it is determined that the feed-response coupling includes a value below the threshold within the target frequency band, in response to this determination, determining that the eye-wearable device is currently being worn; and (c) in the case where it is determined that the feed-response coupling does not exceed the threshold within the target frequency band, in response to this determination, determining that the eye-wearable device is not currently being worn. In some such examples, the method may include performing a device management action, the device management action including: automatically activating a near-eye display in response to determining that the device is currently being worn when the integrated near-eye display of the eye-wearable device is deactivated.

[0050] In an example, the signal processing procedure includes: (a) determining a response signal amplitude at a frequency with the maximum loss within the target frequency band, thereby identifying a minimum amplitude of the response signal within the target frequency band; and (b) based on the minimum amplitude of the response signal, estimating a current value of a frame gap defined by a lateral spacing between the eye-wearable device frame and the wearer's head in the viewing direction. In some such examples, the device management action includes: (a) determining that the minimum amplitude exceeds a threshold of a predefined target frame gap, the predefined target frame gap being conducive to achieving visual clarity of an integrated near-eye display of the eye-wearable device in the wearer's perspective; and (b) automatically communicating an adjustment prompt to the wearer to change the lateral spacing between the eye-wearable device frame and the wearer's head.

[0051] In some examples, the method includes: (a) identifying a frequency at which the loss is greatest, the frequency at which the loss is greatest being the frequency at which the signal loss between the feed loop and the response loop in the target frequency band is greatest; and (b) estimating a current value of the wearer's head size based on the frequency at which the loss of the response signal is greatest. In some such examples, the device management actions include: (a) identifying a particular sub - portion of the available display area provided by the near - eye display for activation based on the current head size value; and (b) autonomously activating the particular sub - portion of the available display area of the near - eye display, thereby adjusting the display position of the near - eye display based on the wearer's head size.

[0052] Other technical features may be apparent to those skilled in the art from the following figures, description, and claims.

[0053] Turning now to a more detailed description of specific example embodiments, Figure 1 An inclined front view of a head - mounted device in the form of an example ocular - wearable device providing a supported display by a pair of smart glasses 100 in this example is shown. The glasses 100 have a native display system 104 that provides a near - eye display capable of supporting AR functionality, and thus are AR glasses. The AR glasses 100 have an integrated head sensor 102 that is capable of measuring or detecting a plurality of attributes or parameters (i.e., head parameters) of the head of the wearer of the AR glasses 100. Example head parameters detectable by using the head sensor 102 include head size, distance of the head from the device, and presence or absence of the head (and thus detecting active wear or its absence), as described in greater detail later herein with reference to Figure 7 (which shows a top view of the head 704 of the wearer 702 of the example AR glasses 100). As used herein, the wearer of the device is the user (if any) who is currently (i.e., at the relevant time described) wearing the relevant device.

[0054] The on - board electronics 106 of the AR glasses 100 include a computer processor that communicates with the head sensor 102 and is configured to provide device management functions for autonomously performing device management actions to adjust or prompt adjustment of selected features of the AR glasses 100 based on the head parameter values detected by the head sensor 102. As will be described in more detail later herein, such autonomous adjustments in response to measured head parameters include, but are not limited to: changing the position of the near - eye display based on the measured head size, prompting adjustment of the spacing between the AR glasses 100 and the wearer's face 706 (referred to as the frame gap; see Figure 7 ), automatically cutting power to at least some powered components when no head presence is detected (i.e., when the AR glasses 100 are not being worn), and automatically activating the display system 104 in response to detecting a head presence consistent with effective wear of the AR glasses 100.

[0055] The body 108 of the AR glasses 100 includes a front piece or an ocular wear device frame 110 and a pair of temple arms 114 that are hingedly connected to the frame 110 for supporting the AR glasses 100 in place on a user's face when the temple arms 114 are in an extended or wearable configuration as shown to accommodate the user's head 704 therebetween. In some examples, the entire frame 110 can be formed from a single piece of material so as to have a unitary or monolithic structure. In this example embodiment, the frame 110 is a metallic component of unitary or monolithic construction. In other embodiments, the frame 110 is at least partially provided by one or more substantially rigid molded components formed from a polymeric plastic material. Figure 1 The AR glasses 100 include a pair of bilateral optical elements in the form of respective lenses 112 received by the frame 110. The lenses 112 are held in the frame 110 in a typical ocular wear device manner such that, during wear, the lenses 112 are positioned immediately in front of the eyes such that the wearer's field of view is substantially completely occupied by the lenses 112. Note that, in some examples, the lenses 112 are compound lenses that include multiple stacked optical elements. In this example, each lens 112 further includes a lens assembly that is configured to not only perform the basic functions of a conventional ocular wear device lens but additionally provide or implement integrated display capabilities, carrying a respective display area 210 of the display system 104 (see

[0056] ). The lens assemblies 114 are held in the frame 110 within respective lens borders 116 defined by the frame 110. Figure 2 ) The lens assemblies 114 are held in the frame 110 within respective lens borders 116 defined by the frame 110.

[0057] In this example, the head sensor 102 is at least partially provided by a loop coupler system that includes a pair of coupler loops provided by (a) a feed conductor in the example form of a feed loop 126 and (b) a response conductor in the form of a response loop 128. As will be further discussed with reference to Figure 2 the coupler loops are coupled to the transceiver to transmit a feed signal and measure a corresponding induced response signal. The feed - response signals are processed to estimate one or more head parameters indicated by the frequency - space amplitude loss in the forward transmission.

[0058] In this example, the AR glasses 100 are configured for wireless communication with external electronic components or devices. To this end, the on-board electronic device 106 includes an antenna system integrated in the frame 110. In some examples, one or both of the feed loop 126 and the response loop 128 form part of the communication antenna system, thus providing a wireless data transmission function in addition to the feed-response head sensing function as disclosed. In this example, the feed loop 126 forms part of the communication antenna system and is used as a Wi-Fi antenna for data communication in the corresponding frequency domain.

[0059] In this example, each of the feed loop 126 and the response loop 128 is provided by an interrupted annular metal strip that is shaped and configured to additionally serve a structural function of removably and replaceably holding the associated lens 112 in the corresponding lens rim 116. In other words, in this example, the feed loop 126 and the response loop 128 each provide a lens holder mechanism or a lens ring.

[0060] In this exemplary embodiment, each of the coupler loops 126, 128 is located in a circumferentially extending channel in the radially inner surface of the lens rim 116 such that the coupler loops 126, 128 extend circumferentially around the outer periphery of the lens 112 and selectively engage the radially outer periphery of the associated lens 112 to hold it in the respective lens rim 116. The lens rings provided by the respective coupler loops 126, 128 can be set between a locked state and an unlocked state. In the locked state, the lens ring is tightened into contact with the radial edge of the lens 112 to hold it in the lens rim 116. In the unlocked state, the coupler loops 126, 128 expand slightly so that the lens can be removed and replaced.

[0061] Figure 2 Additional components of the head sensing system provided at least in part by the head sensor 102 are schematically shown. For example, it can be seen that the head sensor 102 includes a transceiver device that includes a transmitter 220 connected to the feed loop 126 and a receiver 214 connected to the response loop 128. Note that each of the coupler loops 126, 128 is discontinuous and is interrupted by a discontinuity provided by a respective feed slot 222 generated in the metal loop element and the lens rim 116. The respective feed points of the coupler loops 126, 128 to the transmitter 220 and the receiver 214 are located at the respective feed slots 222. In this example, the feed slots 222 are filled with a plastic material while allowing electrical connection of the transceiver device internally.

[0062] In this example, 214 is coupled to transmitter 220 and receiver 214. 214 includes circuitry and / or processing devices configured to derive measurements of one or more head parameters through processing of the feed and response signals. 214 communicates with device management controller 224, which forms part of the on-board electronics and is configured to autonomously effect device adjustments or customization of one or more measured head parameters specific to the wearer.

[0063] In this example, the transceiver device and 214 are housed in the bridge 118 defined by the frame between the lens rims 116, thus reducing wiring complexity. In other examples, the functions of 214 and device management controller 224 are provided by one or more correspondingly programmed processors forming part of the on-board electronics 106 (e.g., provided by Figure 3 the high-speed circuitry 314).

[0064] In operation, RF energy from transmitter 220 feeds the feed loop 126. This energy causes the generation of a feed-side H-field 712 perpendicular to the metal frame 110 (see Figure 7 ), as indicated by the dashed arrows in the plan view of Figure 7 . These H-fields then pass through the air and are picked up by the response loop 128. The captured H-fields generate a current at the feed point of the response loop 128, which in turn causes a response at the receiver, thus providing a measured response signal. In other examples, transmitter 220 and receiver 214 are incorporated into a single transceiver that is indirectly coupled to coupler loops 126, 128 via a circulator. In some examples, transmitter 220 is an established RF system, such as WiFi. In such an example, receiver 214 can even be a simple RF detector circuit.

[0065] Frame 110 defines a pair of end portions 120 at opposite lateral ends of the frame 110, the end portions 120 providing respective internal spaces in which at least a portion of the on-board electronics 106 is housed. In this example, various electronic components are housed in one or both of the end portions 120. Some components of the on-board electronics 106 are also housed in the main portions of the frame 110 and the temple 114.

[0066] The on-board electronics 106 can include one or more processors having memory, wireless communication circuitry, and a power supply. As will be described below with reference to Figure 4As discussed, the on-board electronic device 106 includes a low-power circuit system, a high-speed circuit system, a display processor, a signal processing component for deriving head parameters based on feed and response signals, and a device controller configured to perform autonomous adjustment actions based on currently applicable measured head parameters. Various other examples may include these elements configured differently or integrated together in different ways. The electronic device 106 additionally includes an on-board battery or other suitable portable power source. The on-board electronic device 106 includes a connector or port (not shown) adapted to charge the battery, a wireless receiver, a transmitter, or a transceiver (not shown), or a combination of such devices.

[0067] The AR glasses 100 support a camera device, which in this example includes a pair of camera devices 122 mounted on the frame 110 and facing forward so as to be generally aligned with the wearer's field of view direction. The camera devices 122 are configured to capture digital photos as well as digital video content. Although two camera devices are depicted, other examples contemplate the use of a single or additional (i.e., more than two) camera devices. In one or more examples, in addition to the camera devices 122, the AR glasses 100 further include any number of input sensors or other input / output devices. In this example, in addition to the head sensor 102, the on-board sensors provided by the on-board electronic device 106 further include biometric sensors, position sensors, and motion sensors.

[0068] The AR glasses 100 also include one or more input and output mechanisms that allow communication with the on-board electronic device 106 and control of various functions provided by the on-board electronic device 106, including camera device functions, display functions, and optical screening functions. In this example, the input mechanism includes a pair of buttons 124 mounted on the frame 110 so as to be accessible for user pressing on top of the respective end portions 120. In other embodiments, additional and / or alternative user input mechanisms may be provided by, for example, one or more touch pads located on one or both temple arms 114 for receiving tactile input. Alternatively or additionally, some examples provide control of one or more device functions by a tap sequence manually applied to the body 108 of the AR glasses 100.

[0069] Figure 2 The AR glasses 100 are shown from the wearer's perspective. For clarity, Figure 1 a number of elements shown in Figure 1 are omitted. As

[0070] The display system 104 in this example provides a near-eye display 212 carried by and integrated with the lens 112. In this example, the near-eye display 212 includes a pair of laterally symmetric forward optical components housed in respective end portions 120, each forward optical component including a projector 208 coupled to the associated lens 112 to present a visual image in a corresponding generally rectangular display area 210 on the associated lens 112. Thus, as best seen in Figure 2 each lens 112 has a dedicated projector 208 serving the corresponding display area 210.

[0071] In this example, at least a portion of each composite lens 112 of the near-eye display 212 serves as a waveguide combiner. To this end, each fixed lens waveguide has an input region and an output region provided by a diffractive surface relief grating, where the display area 210 is defined by the corresponding surface relief grating. The waveguide includes reflective or diffractive structures (e.g., gratings and / or optical elements such as mirrors, lenses, or prisms). Thus, the projected light from the projector 208 enters the waveguide provided by the lens 112 at the input region adjacent to the outer periphery of the lens 112 and travels in a waveguide manner through the lens 112 to encounter the diffractive structure that defines the display area 210. The diffractive structure of the display area 210 defines individually addressable display pixels, each of which redirects the light projected onto it from the projector towards the corresponding eye of the wearer, thereby providing a finely pixelated color image that conforms to the lens 112 from the wearer's perspective. It will be understood that the display so provided in the display area 210 is transparent, so that the content of the display appears to be superimposed on the visible environment. However, it will be understood that other display technologies or configurations may be provided that can display images to the user in the forward field of view. For example, instead of the projector 208 and waveguide, an LCD, LED, or other display panel or surface may be provided alternatively.

[0072] Thus, the near-eye display 212 is capable of rendering AR objects 204 that appear to be superimposed on the real-world environment 202. In this example, the AR objects 204 are rendered in a stereoscopic effect in the left and right display areas 210 such that they appear three-dimensional and are located in depth with the surrounding real-world environment 202. The visual content that can be displayed by the near-eye display 212 in AR mode is not limited to stereoscopic and / or superimposed AR content, but also includes conventional 2D materials such as graphical user interfaces, photos, and video content such as movies, TV, sports events, and online video clips or social media stories.

[0073] In this example, the display area 210 as shown depicts the complete area available for display (i.e., the area in which display pixels are located), which in this example is larger in both the horizontal direction and the number of pixels than the effective display area for a "full screen" display. In other words, in this example, the complete extent of the effective display area is provided by a sub - portion of the complete available display area 210. Such an oversized display area 210 effectively allows for adjustment or variation in the position relative to the frame 110 of the corresponding near - eye display 212 by activating the pixels within the sub - portion identified as the effective display area and de - activating the pixels outside of that sub - portion.

[0074] In this example, the display position of the effective display area can be adjusted horizontally (i.e., to the right as viewed from the wearer's perspective when moving left) by selectively activating and de - activating the outer pixels 216 and inner pixels 218 located in the horizontal outer and horizontal inner vertical rectangular strips of the corresponding display area 210, respectively.

[0075] Users with a relatively wide inter - eye distance experience optimal display quality of near - eye displays (and in particular AR display elements) when the horizontal spacing between the effective display areas is relatively large, and vice versa. The provision of selectively activatable outer pixels 216 and inner pixels 218 enables adjustment of the display position by effectively moving the effective display areas (i.e., the left - activated sub - portion and the right - activated sub - portion) closer together or farther apart based on the detected head size or width, which typically indicates the individual's eye spacing.

[0076] System with an eye - worn device supporting an electronic device

[0077] Figure 3 Shows a system according to one example, in which an eye - worn device supporting an electronic device such as the example AR glasses 100 can be implemented. Figure 3 Is a high - level functional block diagram of an example pair of AR glasses 100 that communicatively couples a mobile client device 302 and a server system 328 via various networks 334.

[0078] As previously briefly discussed, the AR glasses 100 include at least one camera device 122, a near - eye display 212, an optical loop coupler system 304, and a signal processor 206 for autonomously controlling the loop coupler system 304.

[0079] The client device 302 can be a smart phone, a tablet computer, a phablet, a laptop computer, an access point, or any other such device capable of connecting to the AR glasses 100 using either or both of a low - power wireless connection 330 and a high - speed wireless connection 332. The client device 302 is connected to the server system 328 and the network 334. The network 334 can include any combination of wired and wireless connections.

[0080] The AR glasses 100 also include two image displays of the near-eye display 212. The two image displays include one image display associated with the left lateral side of the AR glasses 100 and one image display associated with the right lateral side of the AR glasses 100. The AR glasses 100 also include an image display driver 308, an image processor 312, a low-power circuit system 322, and a high-speed circuit system 314. The near-eye display 212 is configured to present images and videos to a user of the AR glasses 100, including images that may include a graphical user interface.

[0081] The image display driver 308 commands and controls the image displays of the near-eye display 212. The image display driver 308 may deliver image data directly to the image displays of the near-eye display 212 for presentation, or may have to convert the image data into a signal or data format suitable for delivery to an image display device. For example, the image data may be video data formatted according to a compression format such as H.264 (MPEG-4 Part 10), HEVC, Theora, Dirac, RealVideo RV40, VP8, VP9, etc., and still image data may be formatted according to a compression format such as Portable Network Graphics (PNG), Joint Photographic Experts Group (JPEG), Tagged Image File Format (TIFF), or Exchangeable Image File Format (Exif).

[0082] As described above, the AR glasses 100 include a frame 110 and temple arms (or temples) extending from the lateral sides of the frame 110. The AR glasses 100 also include one or more user input devices 306, which in this example include a touch sensor and buttons 124. The user input device 306 (e.g., a touch sensor or a button) receives input selections from the user to manipulate the graphical user interface of the presented images.

[0083] Figure 3 The components shown for the AR glasses 100 are located on one or more circuit boards such as a PCB or a flexible PCB in the temples or the frame. Alternatively or additionally, the depicted components may be located in chunks, frames, hinges, or nose bridges of the AR glasses 100. The left and right camera devices 122 may include digital camera device elements, such as complementary metal-oxide-semiconductor (CMOS) image sensors, charge-coupled devices, or any other corresponding visible light or light-capturing elements that may be used to capture data, including images of scenes with unknown objects.

[0084] The AR glasses 100 include a memory 318 that stores instructions for performing a subset or all of the functions described herein. The memory 318 may also include a storage device. In this example, the memory 318 stores instructions for dynamic autonomous mode switching, and the signal processor 206 is implemented via the execution of the instructions by the high-speed circuitry 314.

[0085] As Figure 3 shown, the high-speed circuitry 314 includes a high-speed processor 316, a memory 318, and a high-speed wireless circuitry 320. In the example, the image display driver 308 is coupled to the high-speed circuitry 314 and is operated by the high-speed processor 316 to drive the left and right image displays of the near-eye display 212. The high-speed processor 316 can be any processor capable of managing the operation of any general computing system required for the AR glasses 100 and high-speed communication. The high-speed processor 316 includes the processing resources required to manage high-speed data transmission on the high-speed wireless connection 332 to a wireless local area network (WLAN) using the high-speed wireless circuitry 320. In certain examples, the high-speed processor 316 executes an operating system of the AR glasses 100, such as the LINUX operating system or other such operating systems, and the operating system is stored in the memory 318 for execution. In addition to any other duties, the high-speed processor 316 that executes the software architecture of the AR glasses 100 is used to manage data transmission with the high-speed wireless circuitry 320. In certain examples, the high-speed wireless circuitry 320 is configured to implement the Institute of Electrical and Electronics Engineers (IEEE) 1002.11 communication standard, also referred to herein as Wi-Fi. In other examples, other high-speed communication standards may be implemented by the high-speed wireless circuitry 320.

[0086] The low-power wireless circuitry 326 and the high-speed wireless circuitry 320 of the AR glasses 100 may include a short-range transceiver (Bluetooth TM ) and a wireless wide area network, local area network, or wide area network transceiver (e.g., cellular or WiFi). The client device 302 (including transceivers for communicating via the low-power wireless connection 330 and the high-speed wireless connection 332) may be implemented using the details of the architecture of the AR glasses 100, and so may other elements of the network 334.

[0087] The memory 318 includes any storage device capable of storing various data and applications, including camera device data generated by the left and right camera devices 122, the signal processor 206, and the image processor 312, as well as images generated by the image display driver 308 for display on the image display of the near-eye display 212. Although the memory 318 is shown as integrated with the high-speed circuitry 314, in other examples, the memory 318 can be a separate stand-alone element of the AR glasses 100. In some such examples, electrical wiring lines can provide a connection from the image processor 312 or the low-power processor 324 to the memory 318 through a chip including the high-speed processor 316. In other examples, the high-speed processor 316 can manage the addressing of the memory 318 such that the low-power processor 324 will initiate the high-speed processor 316 at any time when a read or write operation involving the memory 318 is required.

[0088] As Figure 3 shown, the low-power processor 324 or the high-speed processor 316 of the AR glasses 100 can be coupled to the camera device 122, the loop coupler system 304, the low-power processor 324 and / or the high-speed processor 316 (thereby at least partially providing the signal processor 206), the image display driver 308, the user input device 306 (e.g., a touch sensor or a button), and the memory 318.

[0089] The AR glasses 100 are connected to a host computer. For example, the AR glasses 100 are paired with the client device 302 via a high-speed wireless connection 332, or are connected to the server system 328 via the network 334. The server system 328 can be one or more computing devices that are part of, for example, a service or a network computing system, and includes a processor, a memory, and a network communication interface to communicate with the client device 302 and the AR glasses 100 via the network 334.

[0090] The client device 302 includes a processor and a network communication interface coupled to the processor. The network communication interface enables communication via network 334, low-power wireless connection 330, or high-speed wireless connection 332. The client device 302 may also store at least a portion of instructions for implementing autonomous and / or user-guided opacity control functionality via the optical loop coupler system 304 described herein. Thus, in some examples, opacity control may be performed entirely on the device at the AR glasses 100. In other embodiments, at least a portion of the signal processor 206 may be provided by the connected client device 302. In one such embodiment, the client device 302 has installed thereon a machine learning model (ML model) derived from a neural network that was trained with use case training data related to sensor data and use case data where optical filtering is appropriate or implemented manually / selectively by the user. In such a case, the ML model autonomously triggers the loop coupler system 304 and thus the switching of the lens 112 between different optical modes, as described herein and as briefly discussed below with reference to Figure 6 Briefly discussed. In some embodiments, such an ML model may be implemented by the signal processor 206 on the device. In additional embodiments, autonomous opacity control may be provided at least in part by the server system 328, e.g., by using a continuously updated AI system implemented by the server system 328 to control multiple AR glasses 100 communicating with it via network 334.

[0091] The output components of the AR glasses 100 include visual components such as a near-eye display 212 and / or a light-emitting diode (LED) display. The image display of the near-eye display 212 is driven by an image display driver 308. The output components of the AR glasses 100 also include acoustic components (e.g., speakers), haptic components (e.g., vibration motors), other signal generators, etc. The input components of the AR glasses 100, the client device 302, and the server system 328, such as the user input device 306, may include alphanumeric input components (e.g., keyboards, touchscreens configured to receive alphanumeric input, optical keyboards, or other alphanumeric input components), point-based input components (e.g., mice, touchpads, trackballs, joysticks, motion sensors, or other pointing instruments), haptic input components (e.g., buttons 124, touchscreens that provide the location and force of a touch or touch gesture, or other haptic input components), audio input components (e.g., microphones), etc.

[0092] The AR glasses 100 may optionally include additional peripheral device elements. Such peripheral device elements may include on-board device sensors 336, which in this example include biometric sensors, motion sensors, and position sensors integrated with the AR glasses 100. For example, the peripheral device elements may include any I / O components, including output components, motion components, position components, or any other such elements described herein.

[0093] For example, the biometric components of the device sensors 336 include components for detecting expressions (e.g., hand expressions, facial expressions, voice expressions, body postures, or eye tracking), measuring biometric signals (e.g., blood pressure, heart rate, body temperature, sweating, or brain waves), identifying people (e.g., voice recognition, retina recognition, facial recognition, fingerprint recognition, or electroencephalogram-based recognition), etc. The motion components of the device sensors 336 include acceleration sensor components (e.g., accelerometers), gravity sensor components, rotation sensor components (e.g., gyroscopes), etc. The position components include positioning sensor components for generating position coordinates (e.g., global positioning system (GPS) receiver components), WiFi or Bluetooth TM transceivers, altitude sensor components (e.g., altimeters or barometers that detect air pressure, from which altitude can be obtained), orientation sensor components (e.g., magnetometers), etc. Such positioning system coordinates can also be received from the client device 302 via the low-power radio circuitry 326 or the high-speed radio circuitry 320 through the low-power wireless connection 330 and the high-speed wireless connection 332.

[0094] When using phrases similar to "at least one of A, B, or C", "at least one of A, B, and C", "one or more of A, B, or C", or "one or more of A, B, and C", it is intended that the phrase be interpreted to mean that A can exist alone in an embodiment, B can exist alone in an embodiment, C can exist alone in an embodiment, or any combination of elements A, B, and C can exist in a single embodiment; for example, A and B, A and C, B and C, or A and B and C.

[0095] Without departing from the scope of the present disclosure, changes and modifications can be made to the disclosed embodiments. These and other changes or modifications are intended to be included within the scope of the present disclosure as expressed in the appended claims.

[0096] Networked computing environment

[0097] Figure 4 is a block diagram showing an example messaging system 400 for exchanging data (e.g., messages and associated content) over a network. The messaging system 400 includes reference Figure 3Multiple instances of a client device 302 similar to the illustrated client device 302, each instance hosting multiple applications including a messaging client 402 and other applications 404. In this example, the client device 302 is a mobile phone coupled to a pair of AR glasses 100 similar to the AR glasses 100 described with reference to Figures 1 to 3 In other examples, the client device 302 may be provided by the AR glasses 100 itself.

[0098] Each messaging client 402 is communicatively coupled via a network 410 (e.g., the Internet) to other instances of the messaging client 402 (e.g., hosted on corresponding other client devices 302), a messaging server system 406, and a third-party server 408. The messaging client 402 may also communicate with the locally hosted applications 404 using an application programming interface (API). In some examples, the messaging client 402 may be provided by a wearable device such as Figure 1 the AR glasses 100, a client device 302 such as Figure 3 or a combination thereof.

[0099] The messaging client 402 is capable of communicating and exchanging data with other messaging clients 402 and the messaging server system 406 via the network 410. The data exchanged between the messaging clients 402 and between the messaging client 402 and the messaging server system 406 includes functionality (e.g., commands to activate functionality) and payload data (e.g., text, audio, video, or other multimedia data).

[0100] The messaging server system 406 provides server-side functionality to a particular messaging client 402 via the network 410. While certain functions of the messaging system 400 are described herein as being performed by the messaging client 402 or by the messaging server system 406, the location of certain functions within the messaging client 402 or within the messaging server system 406 may be a design choice. For example, it may be technically preferable to initially deploy certain technologies and functionality within the messaging server system 406, but later migrate the technologies and functionality to the messaging client 402 on the client device 302 that has sufficient processing power.

[0101] The messaging server system 406 supports various services and operations provided to the messaging client 402. Such operations include sending data to the messaging client 402, receiving data from the messaging client 402, and processing data generated by the messaging client 402. By way of example, the data can include message content, client device information, geolocation information, media enhancements and overlays, message content persistence conditions, social network information, and live event information. Data exchange within the messaging system 400 is activated and controlled through functions available via the user interface (UI) of the messaging client 402.

[0102] Now turning specifically to the messaging server system 406, the application programming interface (API) server 414 is coupled to the application server 412 and provides a programming interface to the application server 412. The application server 412 is communicatively coupled to the database server 418, which facilitates access to the database 424 that stores data associated with messages processed by the application server 412. Similarly, the web server 426 is coupled to the application server 412 and provides a web-based interface to the application server 412. To this end, the web server 426 processes incoming network requests via the Hypertext Transfer Protocol (HTTP) and several other related protocols.

[0103] The application programming interface (API) server 414 receives and sends message data (e.g., commands and message payloads) between the client device 302 and the application server 412. Specifically, the application programming interface (API) server 414 provides a set of interfaces (e.g., routines and protocols) that the messaging client 402 can call or query to activate the functions of the application server 412. The application programming interface (API) server 414 exposes various functions supported by the application server 412, including: account registration; login functionality; sending messages from a particular messaging client 402 to another messaging client 402 via the application server 412; sending media files (e.g., images or videos) from the messaging client 402 to the messaging server 416 for possible access by another messaging client 402; setting a collection of media data (e.g., a story); retrieving a list of friends of the user of the client device 302; retrieving such a collection; retrieving messages and content; adding and deleting entities (e.g., friends) for an entity graph (e.g., a social graph); locating friends in the social graph; and opening application events (e.g., related to the messaging client 402).

[0104] The application server 412 hosts a number of server applications and subsystems, including, for example, a messaging server 416, an image processing server 420, and a social network server 422. The messaging server 416 implements a number of message processing techniques and functions, particularly those related to the aggregation and other processing of content (e.g., text and multimedia content) included in messages received from multiple instances of the messaging client 402. As will be described in further detail, text and media content from multiple sources can be aggregated into collections of content (e.g., referred to as stories or galleries). These collections are then made available to the messaging client 402. Given the hardware requirements for other processor- and memory-intensive processing of data, such processing can also be performed by the messaging server 416 on the server side.

[0105] The application server 412 also includes an image processing server 420 that is dedicated to performing various image processing operations, typically on images or videos within the payloads of messages sent from or received at the messaging server 416.

[0106] The social network server 422 supports various social networking functions and services and makes these functions and services available to the messaging server 416. To this end, the social network server 422 maintains and accesses an entity graph within a database 424. Examples of functions and services supported by the social network server 422 include identifying other users in the messaging system 400 who have a relationship with or are being "followed" by a particular user, and identifying the interests and other entities of a particular user.

[0107] Returning to the messaging client 402, the features and functionality of external resources (e.g., app 404 or mini-program) are made available to the user via the interface of the messaging client 402. In this context, "external" refers to the fact that the app 404 or mini-program is external to the messaging client 402. External resources are typically provided by a third party, but may also be provided by the creator or provider of the messaging client 402. The messaging client 402 receives a user selection of an option for initiating or accessing the features of such an external resource. The external resource may be an app 404 installed on the client device 302 (e.g., a "native app"), or a scaled-down version of an app hosted on the client device 302 or remote from the client device 302 (e.g., on a third-party server 408) (e.g., a "mini-program"). The scaled-down version of the app includes a subset of the features and functionality of the app (e.g., the full-scale, native version of the app) and is implemented using a markup language document. In one example, the scaled-down version of the app (e.g., a "mini-program") is a web-based markup language version of the app and is embedded within the messaging client 402. In addition to using a markup language document (e.g., a.*ml file), the mini-program may include a scripting language (e.g., a.*js file or a.json file) and a style sheet (e.g., a.*ss file).

[0108] In response to receiving a user selection of an option for initiating or accessing the features of an external resource, the messaging client 402 determines whether the selected external resource is a web-based external resource or a locally installed app 404. In some cases, an app 404 locally installed on the client device 302 may be launched independently of and separately from the messaging client 402, e.g., by selecting an icon corresponding to the app 404 on the home screen of the client device 302. A scaled-down version of such an app may be launched or accessed via the messaging client 402, and in some examples, portions of the scaled-down app may not be accessible outside of the messaging client 402, or a limited portion of the scaled-down app may be accessible outside of the messaging client 402. The scaled-down app may be launched by the messaging client 402, e.g., by receiving a markup language document associated with the scaled-down app from a third-party server 408 and processing such a document.

[0109] In response to determining that the external resource is a locally installed application 404, the messaging client 402 instructs the client device 302 to launch the external resource by executing locally stored code corresponding to the external resource. In response to determining that the external resource is a web-based resource, the messaging client 402 communicates with, e.g., a third-party server 408 to obtain a markup language document corresponding to the selected external resource. The messaging client 402 then processes the obtained markup language document to render the web-based external resource within the user interface of the messaging client 402.

[0110] The messaging client 402 may notify a user of the client device 302 or other users associated with such a user (e.g., "friends") of activities occurring in one or more external resources. For example, the messaging client 402 may provide notifications to participants in a conversation (e.g., a chat session) in the messaging client 402 regarding the current or recent use of an external resource by one or more members of a user group. One or more users may be invited to join an active external resource or to launch an external resource that was recently used but is currently inactive (among the group of friends). The external resource may provide the ability for respective participants using the corresponding messaging client 402 in a conversation to share items, conditions, statuses, or locations within the external resource with one or more members of the user group entering the chat session. The shared item may be an interactive chat card that chat members can use to interact, e.g., to launch the corresponding external resource, view specific information within the external resource, or bring the chat members to a specific location or status within the external resource. Within a given external resource, a response message may be sent to the user on the messaging client 402. The external resource may selectively include different media items in the response based on the current context of the external resource.

[0111] The messaging client 402 may present a list of available external resources (e.g., applications 404 or applets) to launch or access a given external resource. The list may be presented in a context-sensitive menu. For example, the icons representing different applications (or applets) within an application 404 (or applet) may vary based on how the user launches the menu (e.g., from a conversation interface or from a non-conversation interface).

[0112] Figure 5 is a high-level flowchart of a method 500 for autonomously managing a head-mounted optical device, such as an eye-wearable device supporting display. The method will be further described with reference to Figures 1 to 4 an example AR glasses 100, but it will be understood that in other cases, the described techniques may be implemented with different example devices.

[0113] In operation 502, method 500 provides for transmitting an RF feed signal using a feed conductor incorporated into a head-mounted device. In operation 504, method 500 reads a response signal induced in a response conductor in the device by the feed signal. In operation 506, in an automated operation performed by on-board electronics including one or more computer processor devices (processor) housed by the device, method 500 performs a signal processing procedure to derive a current value of a head-affected metric based at least in part on a comparison between the feed signal and the response signal, the head-affected metric being variable as a factor of head parameters related to the head of a wearer on which the device is currently worn. In operation 508, in an autonomous operation performed by the on-board electronics based at least in part on the current value of the head-affected metric, method 500 identifies and implements a device management action related to the head parameters.

[0114] Figure 6 is a flowchart of a more detailed method 600 that schematically illustrates integrated dynamic detection of currently applicable head parameters for a wearer 702 of a head-mounted optical device (see Figure 7 ). For ease of reference, example method 600 will be further described as being performed by an AR glasses 100 consistent with the example shown in Figures 1 to 4 , but it will be understood that in other examples, eye-wear devices of different configurations may be used for performing a similar method. Additionally, the operations of method 600 are performed in this example by the on-board electronics 106 of the AR glasses 100, specifically by a head sensor 102 including a signal processor 206 and by a device management controller 224, but in other embodiments may be performed at least in part by a coupled client device 302 ( Figure 3 ) and / or a server system 328.

[0115] At operation 602, a transmitter 220 automatically drives the transmission of an RF feed signal by a feed loop 126 of the head sensor 102. In some embodiments, such feed signals are continuously generated at set intervals to provide dynamic head parameter sensing on an ongoing basis. In other cases, the feed signal transmission is triggered by a predefined event such as the power-on of the AR glasses 100 of the near-eye display 212.

[0116] In this example, the feed pulse transmission includes sending pulses having a spectral range suitable for head detection, in this example, the spectral range of the pulses spans a preset target frequency band that encompasses those RF frequencies that are associated with the RF absorption characteristics of the human head. Example target frequency band values are apparent from Figure 7 and Figure 8 . In this example, the feed pulses have substantially consistent amplitudes at each frequency within the spectral range of the signal.

[0117] As described above, the transmission of the feed signal generates an H-field that axially extends through the feed loop 126 and is thus perpendicular to the metal eye-wear device frame 110. During the wearing of the AR glasses 100, the frame 110 (and thus the substantially coplanar lenses 112 and coupler loops 126, 128) defines an upright plane that is laterally spaced apart from the proximal front surface of the wearer's head 704 (i.e., the wearer's face 706), and this spacing is referred to as the frame gap 708. Thus, the H-field of the feed signal extends through the feed loop 126 substantially parallel to the viewing direction of the wearer through the lenses 112.

[0118] At operation 604, the receiver 214 listens for a response signal in response to the feed signal, and the intensity curve of the response signal in the frequency domain indicates the RF absorption rate of the nearby environment. In this example, listening for the response signal includes continuous monitoring of the response loop 128 by the receiver 214.

[0119] At operation 606, the receiver 214 reads and records the response signal captured by the response loop 128, which in this example includes measuring the response amplitude and spectral content. Thus, in some embodiments, the resulting response signal data received by the receiver 214 includes a curve of the response signal amplitude versus frequency within a target spectral range, and each measured data point includes a pair of frequency and response amplitude values. Non-negligible variations in the response amplitude are caused by environmental RF absorption and thus indicate environmental RF absorption, which may be caused by external objects near the coupler loops 126, 128. Figure 8 and Figure 9 An example response signal parameter curve according to different examples is shown.

[0120] Due to the tissue composition of the brain, the human head has absorption characteristics determined empirically and / or computationally at RF frequencies. If the AR glasses 100 are worn on the head during measurement, the feed-side H-field 712 generated by the feed loop 126 will be absorbed by the brain tissue portion in the wearer's head 704. This will reduce the amount of energy available for capture by the response loop 128.

[0121] The closer the head 704 is to the response loop 128 (i.e., the smaller the frame gap 708), the more energy absorption will occur and the less energy will be available for the response loop 128. However, when the head 704 is further away from the feed loop 126, more energy will be available for the response loop 128. Thus, the frame gap value is identified as a head attribute that is a factor in the change of the response amplitude at a specific corresponding frequency. In other words: In some examples, the current frame gap value is inferred or estimated based on the measured response amplitude at a specific RF frequency that is maximally absorbed by the head 704.

[0122] In this example, the frequency separation signal coupling strength is represented by a metric called S21, which is a scattering parameter for forward transmission. Figure 8 and Figure 9 The corresponding example response signal curve of represents the distribution of the S21 parameter within the target frequency spectrum. The size of the head 704 (e.g., the head or face width value) and the design of the loop coupler system play a key role in determining the specific frequency at which this phenomenon is maximally amplified.

[0123] The inventors simulated an example of this phenomenon using a SAM phantom head 704 and a representative AR metal frame 110. Figure 8 The graph 802 of shows the results of multiple simulation cases that vary only in the size of the frame gap 708. It will be observed that when no head is present, the signal coupling is relatively strong, averaging approximately -15 dB. When the phantom head is introduced, the coupling drops to -30 dB at 2.35 GHz. As the phantom head gets closer to the AR frame 110, the coupling gradually weakens, dropping to a minimum of approximately -50 dB. For the example presented here, 2.35 GHz is where this effect is most pronounced. This frequency can be tuned by changing the size of the coupler loops 126, 128 or their feed positions.

[0124] Another head parameter for which the response signal is a factor is the size of the head 704. More specifically, the inventors specifically recognized that the size value of the face 706 (in this example, the face width) affects the frequency at which the brain tissue absorbs the most energy from the loop coupler system, which is also referred to herein as the frequency of maximum loss. A larger head 704 contributes to a significant increase in the effective dielectric constant faced by the coupler loops 126, 128, resulting in maximum absorption (i.e., minimum response amplitude) at lower frequencies. In other words, the frequency of maximum loss decreases as the face or skull width increases.

[0125] Similarly, a smaller head 704 contributes to a small increase in the effective dielectric constant faced by the coupler, resulting in a higher frequency of maximum loss, where maximum absorption occurs at higher frequencies. Additionally, it was found that the figure of merit for this coupling is the S21 scattering parameter for forward transmission. An example of this phenomenon is represented by Figure 9 the graph 902 of, which corresponds to graph 802, except that the head parameter whose value varies between different simulations is the face width 710 (instead of the frame gap 708 in graph 802).

[0126] As observed from graph 902, when no head is present, the coupling is relatively strong, averaging at approximately -15 dB. When a nominal head model is introduced, the coupling drops to -30 dB at 2.35 GHz. If the head model 704 is scaled by 0.9 times, the frequency at which the loss is maximum shifts upward to 2.45 GHz. Similarly, if the head model is scaled by 1.1 times, the frequency at which the loss is maximum shifts downward to 2.25 GHz. These frequency values can be changed by altering the coupler design; however, the basic effect of the head 704 will remain unchanged.

[0127] A smaller head 704 will have a higher maximum absorption frequency (i.e., the frequency at which the loss is maximum), and a larger head will have a lower frequency at which the loss is maximum. In other words: In some examples, the value of the facial width 710 or the head size of the human head 704 on which the device is mounted during measurement is inferred or derived based on the frequency value at which the loss is maximum due to feed - response coupling.

[0128] Now returning to Figure 6 , the example method also includes, at operation 616, determining whether the response signal amplitude at any frequency within the target spectral range is below a preset threshold. From a different perspective, operation 616 determines whether the measured response curve resembles the curve in graph 902 legend "Coupler only, no head".

[0129] If any response amplitude below the threshold is identified within the target frequency band, the head sensor system is interpreted as having detected the presence of the head on which the AR glasses 100 are mounted. In response to such a detection of the head presence (indicating an active wearing state), in this example, the device management controller 224 autonomously triggers a response device management action or adjustment action that includes activating the near - eye display 212 at operation 620.

[0130] On the other hand, if at operation 616 it is determined that the value of the response signal amplitude throughout the target frequency band is above the threshold, the head sensor system identifies the current wearing state as not worn, and in response thereto, at operation 618, autonomously powers off at least some of the powered - on components of the AR glasses 100.

[0131] At operation 608, the receiver 214 determines the value of the minimum amplitude of the response signal within the frequency band. Referring to graph 802 and graph 902, it will be understood that such a minimum response amplitude is provided by the measured response signal amplitude at the frequency within the frequency band of the response signal at which the loss is maximum.

[0132] At operation 610, the identified minimum response signal amplitude value is compared to a preset target amplitude that includes amplitude values, or in this case, to an amplitude range bounded by an upper threshold and a lower threshold in this example. The target amplitude is pre-determined to be related to a target frame gap identified as promoting optimal optical quality of the near-eye display. For example, the target frame gap is a frame gap value at which the near-eye display 212 most reliably focuses for the wearer 702.

[0133] If operation 610 identifies that the minimum response amplitude exceeds the upper threshold of the target minimum amplitude, the device management controller 224 provides an adjustment prompt to the wearer 702 at operation 614 to decrease the frame gap 708, that is, to move the eye-wear device frame 110 closer to their face 706.

[0134] However, if operation 610 identifies that the minimum response amplitude drops below the lower threshold of the target minimum amplitude, the device management controller 224 prompts the wearer 702 at operation 612 to increase the frame gap, that is, to move the frame 110 away from their face 706. In some examples, the adjustment prompt may indicate a recommended distance for the prompted adjustment in the frame gap 708.

[0135] In some iterations, the method further includes, at operation 622, comparing the feed signal to the spectral content of the received response signal, thereby calculating, for example, a response curve similar or analogous to Figure 8 and Figure 9 that plots the response signal amplitude versus frequency within a target spectral range.

[0136] At operation 624, the receiver 214 analyzes the response curve frequency distribution to identify the frequency with the greatest loss, that is, the frequency at which the received spectral content is weakest.

[0137] At operation 626, the signal processor estimates a head width value based on the applicable frequency with the greatest loss and a pre-established look-up table that provides empirically or simulated look-up data for converting the frequency response to a head size (in this case, head width). As previously mentioned, a lower frequency with the greatest loss is associated with a larger head size value, and vice versa.

[0138] At operation 614, the device management controller 224 autonomously adjusts the lateral display position of the corresponding near-eye display area 210 to optimize its visibility for an estimated head width that is related to the lateral distance between the user's eyes. In this example, for a smaller head width dimension, the lateral spacing between the left active display area and the right active display area within the potential display area 210 is automatically reduced, and for a larger head width value, the left and right active display areas are laterally displaced. Thus, in the example implementation described with reference to Figure 2 at operation 628, the display pixels that are optimally optimized for a given head size are activated. For example, in this example, a smaller detected head size triggers the activation of the internal pixels 218, and a larger head size triggers the activation of the external pixels 216.

[0139] Benefits of head attribute sensing and autonomous responsive device adjustment include seamless automatic detection of the wear state, thus saving power by automatically turning off functions when not worn. Autonomous adjustment of the display position customized according to the wearer's facial parameters promotes eye safety by avoiding eye fatigue caused by viewing sub-optimally positioned display pixels and / or out-of-focus displays resulting from sub-optimal frame gap values.

[0140] Machine architecture

[0141] Figure 10is an illustrative representation of a machine 1000 within which instructions 1010 (e.g., software, program, application, applet, app, or other executable code) can be executed to cause the machine 1000 to perform any one or more of the methods discussed herein. For example, the instructions 1010 can cause the machine 1000 to perform any one or more of the methods described herein. The instructions 1010 transform the general unprogrammed machine 1000 into a particular machine 1000 programmed to perform the described and illustrated functions in the described manner. The machine 1000 can operate as a stand-alone device or can be coupled (e.g., networked) to other machines. In a networked deployment, the machine 1000 can operate in a server-client network environment as a server machine or a client machine, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine 1000 can include, but is not limited to: server computers, client computers, personal computers (PCs), tablet computers, laptop computers, netbooks, set-top boxes (STBs), personal digital assistants (PDAs), entertainment media systems, cellular telephones, smart phones, mobile devices, wearable devices (e.g., smart watches), smart home devices (e.g., smart appliances), other smart devices, web appliances, network routers, network switches, network bridges, or any machine capable of executing the instructions 1010 sequentially or otherwise to perform the actions specified to be taken by the machine 1000. Further, while only a single machine 1000 is shown, the term "machine" shall also be taken to include a collection of machines that individually or jointly execute the instructions 1010 to perform any one or more of the methods discussed herein. For example, the machine 1000 can include a client device 302 or any one of a number of server devices forming part of a messaging server system 406. In some examples, the machine 1000 can also include both a client system and a server system, where certain operations of a particular method or algorithm are executed on the server side and certain operations of a particular method or algorithm are executed on the client side.

[0142] Machine 1000 may include a processor 1004, a memory 1006, and an input / output (I / O) component 1002 that may be configured to communicate with each other via a bus 1040. In an example, the processor 1004 (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a radio frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor 1008 and a processor 1012 that execute instructions 1010. The term "processor" is intended to include multi-core processors, which may include two or more independent processors (sometimes referred to as "cores") that may execute instructions simultaneously. Although Figure 10 multiple processors 1004 are shown, machine 1000 may include a single processor with a single core, a single processor with multiple cores (e.g., a multi-core processor), multiple processors with a single core, multiple processors with multiple cores, or any combination thereof.

[0143] Memory 1006 includes a main memory 1014, a static memory 1016, and a storage unit 1018, all of which may be accessed by processor 1004 via bus 1040. The main memory 1006, the static memory 1016, and the storage unit 1018 store instructions 1010 that embody any one or more of the methods or functions described herein. The instructions 1010 may also reside, completely or partially, within the main memory 1014, within the static memory 1016, within a machine-readable medium 1020 within the storage unit 1018, within at least one of the processors 1004 (e.g., within a cache memory of the processor), or within any suitable combination thereof during execution by machine 1000.

[0144] The I / O component 1002 may include various components that receive input, provide output, generate output, transmit information, exchange information, capture measurement results, etc. The specific I / O components 1002 included in a particular machine will depend on the type of the machine. For example, a portable machine (e.g., a mobile phone) may include a touch input device or other such input mechanism, while a headless server machine will likely not include such a touch input device. It should be understood that the I / O component 1002 may include Figure 10Many other components not shown. In various examples, I / O component 1002 may include user output component 1026 and user input component 1028. User output component 1026 may include visual components (e.g., near-eye displays such as plasma near-eye display panels (PDPs), light-emitting diode (LED) near-eye displays, liquid crystal near-eye displays (LCDs), projectors, or cathode ray tubes (CRTs)), acoustic components (e.g., speakers), haptic components (e.g., vibration motors, resistance mechanisms), other signal generators, etc. User input component 1028 may include alphanumeric input components (e.g., keyboards, touchscreens configured to receive alphanumeric input, optical keyboards, or other alphanumeric input components), point-based input components (e.g., mice, touchpads, trackballs, joysticks, motion sensors, or other pointing instruments), haptic input components (e.g., physical buttons, touchscreens that provide the location and force of a touch or touch gesture, or other haptic input components), audio input components (e.g., microphones), etc.

[0145] In other examples, I / O component 1002 may include biometric component 1030, motion component 1032, environmental component 1034, or location component 1036 and various other components. For example, biometric component 1030 includes components for detecting expressions (e.g., hand expressions, facial expressions, voice expressions, body postures, or eye tracking), measuring biometric signals (e.g., blood pressure, heart rate, body temperature, sweating, or brain waves), identifying people (e.g., voice recognition, retina recognition, facial recognition, fingerprint recognition, or electroencephalogram-based recognition), etc. Motion component 1032 includes acceleration sensor components (e.g., accelerometers), gravity sensor components, rotational sensor components (e.g., gyroscopes).

[0146] Environmental component 1034 includes, for example, one or more camera devices (with still image / photo and video capabilities), lighting sensor components (e.g., photometers), temperature sensor components (e.g., one or more thermometers for detecting ambient temperature), humidity sensor components, pressure sensor components (e.g., barometers), acoustic sensor components (e.g., one or more microphones for detecting background noise), proximity sensor components (e.g., infrared sensors for detecting nearby objects), gas sensors (e.g., gas detection sensors for detecting the concentration of hazardous gases for safety or measuring pollutants in the atmosphere), or other components that can provide indications, measurements, or signals corresponding to the surrounding physical environment.

[0147] Regarding the imaging device, the client device 302 may have an imaging device system that includes, for example, a front imaging device on the front surface of the client device 302 and a rear imaging device on the rear surface of the client device 302. The front imaging device may be used, for example, to capture still images and videos of the user of the client device 302 (e.g., "selfies"), and then the still images and videos may be enhanced using the above-described enhancement data (e.g., filters). The rear imaging device may be used, for example, to capture still images and videos in a more traditional imaging device mode, where the images are similarly enhanced using the enhancement data. In addition to the front imaging device and the rear imaging device, the client device 302 may also include a 360° imaging device for capturing 360° photos and videos.

[0148] Furthermore, the imaging device system of the client device 302 may include a dual rear imaging device (e.g., a primary imaging device and a depth sensing imaging device), or even a triple, quadruple, or quintuple rear imaging device configuration on the front and rear sides of the client device 302. For example, these multi-imaging device systems may include a wide-angle imaging device, an ultra-wide-angle imaging device, a telephoto imaging device, a macro imaging device, and a depth sensor.

[0149] The location component 1036 includes a location sensor component (e.g., a GPS receiver component), an altitude sensor component (e.g., an altimeter or barometer that detects air pressure, from which altitude can be obtained), an orientation sensor component (e.g., a magnetometer), etc.

[0150] A variety of techniques may be used to implement communication. The I / O component 1002 also includes a communication component 1038 that is operable to couple the machine 1000 to the network 1022 or the device 1024 via a respective coupling or connection. For example, the communication component 1038 may include a network interface component that interfaces with the network 1022 or other suitable devices. In another example, the communication component 1038 may include a wired communication component, a wireless communication component, a cellular communication component, a near field communication (NFC) component, components (e.g., low power), components, and other communication components that provide communication via other modalities. The device 1024 may be another machine or any of a variety of peripheral devices (e.g., a peripheral device coupled via USB).

[0151] In addition, communication component 1038 can detect components that indicate or include components operable to detect an indication. For example, communication component 1038 can include a radio frequency identification (RFID) tag reader component, an NFC smart tag detection component, an optical reader component (e.g., an optical sensor for detecting one-dimensional barcodes such as Universal Product Code (UPC) barcodes, multi-dimensional barcodes such as Quick Response (QR) codes, Aztec codes, Data Matrix, Dataglyph, MaxiCode, PDF417, Ultra Code, UCC RSS-2D barcodes, and other optical codes), or an acoustic detection component (e.g., a microphone for identifying an audio signal of a tag). Additionally, various information can be derived via communication component 1038, such as a location derived via Internet Protocol (IP) geolocation, a location derived via Wi-Fi signal triangulation, a location derived via detecting an NFC beacon signal that can indicate a specific location, etc.

[0152] Various memories (e.g., main memory 1014, static memory 1016, and the memory of processor 1004) and storage unit 1018 can store one or more sets of instructions and data structures (e.g., software) implemented or used by any one or more of the methods or functions described herein. When executed by processor 1004, these instructions (e.g., instruction 1010) cause various operations to implement the disclosed examples.

[0153] Instructions 1010 can be sent or received over network 1022 via a network interface device (e.g., the network interface component included in communication component 1038) using a transmission medium and any one of several well-known transmission protocols (e.g., Hypertext Transfer Protocol (HTTP)). Similarly, instructions 1010 can be sent or received using a transmission medium via a coupling (e.g., a peer-to-peer coupling) to device 1024.

[0154] Software architecture

[0155] Figure 11FIG. 1100 is a block diagram showing a software architecture 1104 that can be installed on any one or more of the devices described herein. The software architecture 1104 is supported by hardware, such as a machine 1102 that includes a processor 1120, a memory 1126, and I / O components 1138. In this example, the software architecture 1104 can be conceptualized as a stack of layers, where each layer provides a specific function. The software architecture 1104 includes the following layers, such as an operating system 1112, libraries 1110, frameworks 1108, and applications 1106. In operation, the application 1106 activates API calls 1150 through the software stack and receives messages 1152 in response to the API calls 1150.

[0156] The operating system 1112 manages hardware resources and provides common services. The operating system 1112 includes, for example, a kernel 1114, services 1116, and drivers 1122. The kernel 1114 serves as an abstraction layer between the hardware and other software layers. For example, the kernel 1114 provides functions such as memory management, processor management (e.g., scheduling), component management, networking, and security settings. The services 1116 can provide other common services for other software layers. The drivers 1122 are responsible for controlling or interfacing with the underlying hardware. For example, the drivers 1122 can include near-eye display drivers, camera device drivers, Bluetooth or Bluetooth Low Energy drivers, flash drivers, serial communication drivers (e.g., USB drivers), WI-FI drivers, audio drivers, power management drivers, etc.

[0157] The libraries 1110 provide common low-level infrastructure used by the applications 1106. The libraries 1110 can include system libraries 1118 (e.g., C standard libraries) that provide functions such as memory allocation functions, string manipulation functions, mathematical functions, etc. In addition, the libraries 1110 can include API libraries 1124, such as media libraries (e.g., libraries for supporting the presentation and manipulation of various media formats, such as Moving Picture Experts Group - 4 (MPEG4), Advanced Video Coding (H.264 or AVC), Moving Picture Experts Group Layer - 3 (MP3), Advanced Audio Coding (AAC), Adaptive Multi-Rate (AMR) audio codec, Joint Photographic Experts Group (JPEG or JPG), or Portable Network Graphics (PNG)), graphics libraries (e.g., the OpenGL framework for presenting graphical content in two-dimensional (2D) and three-dimensional (3D) on a near-eye display), database libraries (e.g., SQLite that provides various relational database functions), web libraries (e.g., WebKit that provides web browsing functions), etc. The libraries 1110 can also include various other libraries 1128 to provide many other APIs to the applications 1106.

[0158] The framework 1108 provides a common high-level infrastructure for use by the applications 1106. For example, the framework 1108 provides various graphical user interface (GUI) functions, high-level resource management, and high-level location services. The framework 1108 may provide a wide range of other APIs that can be used by the applications 1106, some of which may be specific to a particular operating system or platform.

[0159] In an example, the applications 1106 may include a home application 1136, a contacts application 1130, a browser application 1132, a book reader application 1134, a location application 1142, a media application 1144, a messaging application 1146, a gaming application 1148, and a variety of other applications such as third-party applications 1140. The applications 1106 are programs that execute functions defined in the programs. One or more of the applications 1106 can be created using various programming languages, such as object-oriented programming languages (e.g., Objective-C, Java, or C++) or procedural programming languages (e.g., C or assembly language), which are structured in various ways. In a particular example, a third-party application 1140 (e.g., an application developed using an ANDROID TM or IOS TM software development kit (SDK) by an entity other than the vendor of a particular platform) can be mobile software that runs on a mobile operating system such as IOS TM 、ANDROID TM 、 Phone or other mobile operating systems. In this example, the third-party application 1140 can activate API calls 1150 provided by the operating system 1112 to facilitate the functions described herein.

[0160] Glossary

[0161] "Carrier signal" means any non-tangible medium that can store, encode, or carry instructions executed by a machine and includes digital or analog communication signals or other non-tangible media that facilitate the communication of such instructions. Instructions can be sent or received over a network using a transmission medium via a network interface device.

[0162] "Client device" means any machine that interfaces with a communication network to obtain resources from one or more server systems or other client devices. A client device can be, but is not limited to, a mobile phone, a desktop computer, a laptop computer, a portable digital assistant (PDA), a smartphone, a tablet computer, a superbook, a netbook, a laptop computer, a multiprocessor system, a microprocessor-based or programmable consumer electronics product, a gaming console, a set-top box, or any other communication device that a user can use to access a network.

[0163] "Communication network" means one or more portions of a network, which can be an ad hoc network, an intranet, an extranet, a virtual private network (VPN), a local area network (LAN), a wireless LAN (WLAN), a wide area network (WAN), a wireless WAN (WWAN), a metropolitan area network (MAN), the Internet, a portion of the Internet, a portion of the public switched telephone network (PSTN), a plain old telephone service (POTS) network, a cellular telephone network, a wireless network, a Wi-Fi network, other types of networks, or a combination of two or more such networks. For example, the network or a portion of the network can include a wireless network or a cellular network, and the coupling can be a code division multiple access (CDMA) connection, a global system for mobile communications (GSM) connection, or other types of cellular or wireless couplings. In this example, the coupling can implement any data transmission technology among various types of data transmission technologies, such as single carrier radio transmission technology (1xRTT), evolved data optimized (EVDO) technology, general packet radio service (GPRS) technology, enhanced data rate GSM evolution (EDGE) technology, the third generation partnership project (3GPP) including 3G, the fourth generation wireless (4G) network, universal mobile telecommunications system (UMTS), high speed packet access (HSPA), worldwide interoperability for microwave access (WiMAX), long term evolution (LTE) standard, other data transmission technologies defined by various standards setting organizations, other long distance protocols, or other data transmission technologies.

[0164] "Component" refers to a logical, device, or physical entity having a boundary that is defined by a function or subroutine call, a branch point, an API, or other techniques that provide partitioning or modularity for a particular processing or control function. Components can be combined with other components via their interfaces to perform machine processing. A component can be an encapsulated functional hardware unit designed to be used with other components and can be part of a program that typically performs a specific function among related functions. Components can constitute software components (e.g., code implemented on a machine-readable medium) or hardware components. A "hardware component" is a tangible unit capable of performing certain operations and can be configured or arranged in some physical manner. In various examples, one or more computer systems (e.g., stand-alone computer systems, client computer systems, or server computer systems) or one or more hardware components of a computer system (e.g., a processor or a group of processors) can be configured by software (e.g., an application or a portion of an application) to operate as a hardware component that performs some of the operations described herein. A hardware component can also be implemented mechanically, electronically, or any suitable combination thereof. For example, a hardware component can include dedicated circuitry or logic that is permanently configured to perform certain operations. A hardware component can be a dedicated processor, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). A hardware component can also include programmable logic or circuitry that is temporarily configured by software to perform certain operations. For example, a hardware component can include software executed by a general purpose processor or other programmable processor. Once configured by such software, the hardware component becomes a particular machine (or a particular component of a machine) uniquely customized to perform the configured function and is no longer a general purpose processor. It should be recognized that the decision of whether to implement a hardware component mechanically in dedicated and permanently configured circuitry or in temporarily configured (e.g., software-configured) circuitry can be made for cost and time considerations. Thus, the phrase "hardware component" (or "hardware-implemented component") should be understood to include a tangible entity, i.e., an entity that is physically constructed, permanently configured (e.g., hard-wired), or temporarily configured (e.g., programmed) to operate in some manner or perform some of the operations described herein. Considering an example where a hardware component is temporarily configured (e.g., programmed), it is not necessary to configure or instantiate every hardware component at any given time. For example, in the case where a hardware component includes a general purpose processor that is configured by software to become a dedicated processor, the general purpose processor can be configured at different times to be respective different dedicated processors (e.g., including different hardware components). The software accordingly configures one or more specific processors to, for example, constitute a particular hardware component at one moment and different hardware components at different moments. Hardware components can provide information to and receive information from other hardware components. Thus, the described hardware components can be considered to be communicatively coupled.In the presence of multiple hardware components, communication can be achieved through signal transmission between two or more of the hardware components (e.g., via appropriate circuitry and buses). In examples where multiple hardware components are configured or instantiated at different times, communication between such hardware components can be achieved, for example, by storing information in a memory structure accessible to the multiple hardware components and retrieving the information from the memory structure. For example, one hardware component can perform an operation and store the output of the operation in a memory device to which it is communicatively coupled. Then, another hardware component can access the memory device at a subsequent time to retrieve the stored output and process the stored output. The hardware components can also initiate communication with an input device or an output device and can operate on resources (e.g., a collection of information). The various operations of the example methods described herein can be performed, at least in part, by one or more processors that are temporarily configured (e.g., via software) or permanently configured to perform the associated operations. Whether temporarily or permanently configured, such processors can constitute processor-implemented components that operate to perform one or more of the operations or functions described herein. As used herein, a "processor-implemented component" refers to a hardware component implemented using one or more processors. Similarly, the methods described herein can be at least in part processor-implemented, where a particular one or more processors are examples of hardware. For example, at least some of the operations of the method can be performed by one or more processors 1004 or processor-implemented components. Additionally, the one or more processors can also operate to support the execution of associated operations in a "cloud computing" environment or as a "software as a service" (SaaS) operation. For example, at least some of the operations can be performed by a group of computers (as examples of machines including processors), where the operations are accessible via a network (e.g., the Internet) and via one or more appropriate interfaces (e.g., an API). The execution of certain operations can be distributed among the processors, not residing only within a single machine but being deployed across several machines. In some examples, the processors or processor-implemented components can be located in a single geographical location (e.g., within a home environment, an office environment, or a server farm). In other examples, the processors or processor-implemented components can be distributed across several geographical locations.

[0165] "Computer-readable storage medium" refers to both machine storage media and transmission media. Thus, these terms include both storage devices / media and carrier / modulated data signals. The terms "machine-readable medium", "computer-readable medium", and "device-readable medium" mean the same thing and can be used interchangeably in this disclosure.

[0166] "Ephemeral message" refers to a message that is accessible for a limited duration. Ephemeral messages can be text, images, videos, etc. The access time for an ephemeral message can be set by the message sender. Alternatively, the access time can be a default setting or a setting specified by the recipient. Regardless of the setting technique, the message is transient.

[0167] "Machine storage medium" refers to a single or multiple storage devices and media (e.g., centralized or distributed databases, and associated caches and servers) that store executable instructions, routines, and data. Thus, the term should be considered to include, but not be limited to, solid-state memories as well as optical and magnetic media, including memories internal or external to a processor. Specific examples of machine storage media, computer storage media, and device storage media include: non-volatile memories, including, for example, semiconductor memory devices such as erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), FPGA, and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The terms "machine storage medium", "device storage medium", and "computer storage medium" mean the same thing and may be used interchangeably in this disclosure. The terms "machine storage medium", "computer storage medium", and "device storage medium" expressly exclude carrier waves, modulated data signals, and other such media, at least some of which are subsumed under the term "signal medium".

[0168] "Non-transitory computer-readable storage medium" refers to a tangible medium that can store, encode, or carry instructions executable by a machine.

[0169] "Signal medium" refers to a medium that can store, encode, or carry instructions executable by a machine and includes digital or analog communication signals or other intangible media that facilitate the communication of software or data. The term "signal medium" should be considered to include any form of modulated data signal, carrier wave, etc. The term "modulated data signal" refers to a signal that has one or more of its characteristics set or changed to encode information therein. The terms "transmission medium" and "signal medium" mean the same thing and may be used interchangeably in this disclosure.

Claims

1. A device, comprising: a device body configured to be supported on the head of a wearer of the device in use; a head sensor, the head sensor comprising: a feed conductor received by the device body; a response conductor received by the device body at a position spaced apart from the feed conductor; and a transceiver device coupled to the feed conductor and the response conductor, the transceiver being configured to perform operations including: transmitting a radio frequency (RF) feed signal via the feed conductor; and reading a response signal induced in the response conductor by the feed signal; and one or more computer processor devices forming part of on-board electronics and configured to perform operations including: performing a signal processing procedure to derive a current value of a head-affected metric at least in part based on a comparison between the feed signal and the response signal, the head-affected metric being variable in use as a factor of a head parameter of a wearer wearing the device on the head; and identifying and implementing device management actions related to the head parameter.

2. The device according to claim 1, wherein, the device is an eye-wearable device, further comprising: a loop coupler system providing the feed conductor and the response conductor in the form of paired coupler loops, the loop coupler system comprising: a feed loop driven by the transceiver device to transmit the feed signal; and a response loop coupled to the transceiver device to receive the response signal, the response loop being inductively coupled to the feed loop, wherein the device body includes an eye-wearable device frame carrying lenses, and the coupler loops are received by the eye-wearable device frame such that each of the coupler loops lies in a respective operating upright plane oriented transversely to the operating viewing direction of the device.

3. The device according to claim 2, wherein, the eye-wearable device frame holds a laterally spaced pair of lenses, and wherein each of the coupler loops extends peripherally around a respective one of the pair of lenses, each coupler loop being substantially coplanar with the respective lens.

4. The device according to claim 2 or claim 3, wherein, the on-board electronics are configured to perform the signal processing procedure at least in part based on analyzing a parameter indicative of forward transmission efficiency within a spectrum range spanning a target frequency band of RF frequencies associated with the absorption characteristics of the human head.

5. The device according to claim 4, wherein, the head parameter includes a wearing state indicating whether the device is currently being worn.

6. The device according to claim 5, wherein, the on-board electronics are configured to derive the wearing state by operations including: Determining that the device is currently being worn in the case where the feed - response coupling at a frequency within the target frequency band drops below a predefined threshold; and Determining that the device is currently not being worn in the case where the feed - response coupling is higher in intensity than a threshold within the frequency spectrum range.

7. The device according to claim 6, wherein, The device management action includes: automatically activating the near - eye display in response to determining that the device is currently being worn when the integrated near - eye display of the device is deactivated.

8. The device according to claim 4, wherein, The head parameter includes a frame gap defined by a lateral spacing between the frame of the eye - worn device and the wearer's head in the viewing direction.

9. The device according to claim 8, wherein, The on - board electronics are configured to derive the head - affected metric indicating the current frame gap value through a process that at least partially includes determining the response signal amplitude at the frequency with the maximum loss within the target frequency band, thereby identifying the minimum amplitude of the response signal within the target frequency band.

10. The device according to claim 9, wherein, The device management action includes: Determining that the minimum amplitude exceeds a threshold of a predefined target frame gap that is conducive to achieving visual clarity of the near - eye display incorporated in the eye - worn device from the wearer's perspective; and Automatically communicating an adjustment prompt to the wearer to change the lateral spacing between the frame of the eye - worn device and the wearer's head.

11. The device according to claim 4, wherein, The head parameter includes a head size that quantifies one or more dimensions of the wearer's head.

12. The device according to claim 11, wherein, The on - board electronics are configured to derive the current value of the head - affected metric in a process that at least partially includes the following operations: Identifying the frequency with the maximum loss, which is the frequency at which the signal loss between the feed loop and the response loop within the target frequency band is the greatest; and Estimating the current head size value based on the frequency with the maximum loss of the response signal.

13. The device according to claim 12, wherein, Estimating the current head size value includes a look - up operation that uses the frequency with the maximum loss as a reference value to query look - up data including multiple values of the frequency with the maximum loss associated with different corresponding head size values.

14. The device according to claim 13, wherein, The device management action includes: Based on the current head size value, identifying a specific sub - portion of the available display area provided by the integrated near - eye display for activation; and Autonomously activating the specific sub - portion of the available display area of the near - eye display, thereby adjusting the display position of the near - eye display based on the wearer's head size.

15. A method, comprising: Transmitting a radio frequency (RF) feed signal using a feed conductor incorporated in a head - mounted device; Read a response signal induced by the feed signal in a response conductor incorporated in the device; In an automated operation performed by on-board electronics, perform a signal processing procedure to derive a current value of a head-affected metric based at least in part on a comparison between the feed signal and the response signal, the head-affected metric being variable as a factor of a head parameter related to the head of a wearer currently wearing the device, wherein the on-board electronics are housed by the device and include one or more computer processor device processors; And In an autonomous operation performed by the on-board electronics based at least in part on the current value of the head-affected metric, identify and implement a device management action related to the head parameter.

16. The method according to claim 15, Wherein: The device is an eye-wearable device, the eye-wearable device including an eye-wearable device frame that bears a lens; Wherein the device further includes a loop coupler system having a pair of coupler loops that serve as the feed conductor and the response conductor, respectively, each coupler loop extending circumferentially around an associated lens held by the eye-wearable device frame; and Wherein the signal processing procedure is based at least in part on analyzing a variation in feed-response coupling within a frequency spectrum that spans a target frequency band of RF frequencies associated with absorption characteristics of the human head.

17. The method according to claim 16, further Including: Identifying a wearing state of the eye-wearable device, the wearing state indicating whether the eye-wearable device is currently being worn, identifying the wearing state including: Determining whether a feed-response coupling efficiency drops below a predefined threshold for any frequency within the target frequency band; In the case where it is determined that the feed-response coupling includes a value below the threshold within the target frequency band, in response to this determination, determining that the eye-wearable device is currently being worn; and In the case where it is determined that the feed-response coupling does not exceed the threshold within the target frequency band, in response to this determination, determining that the eye-wearable device is currently not being worn.

18. The method according to claim 17, Wherein, The device management action includes: automatically activating the near-eye display in response to determining that the device is currently being worn when the integrated near-eye display of the eye-wearable device is deactivated.

19. The method according to claim 16, Wherein, The signal processing procedure includes: Determining an amplitude of the response signal at a frequency with the maximum loss within the target frequency band, thereby identifying a minimum amplitude of the response signal within the target frequency band; and Based on the minimum amplitude of the response signal, estimating a current value of a frame gap defined by a lateral spacing between the eye-wearable device frame and the wearer's head in a viewing direction.

20. The method according to claim 19, Wherein, The device management action includes: Determine a threshold at which the minimum amplitude exceeds a predefined target frame gap that facilitates achieving visual clarity of a near-eye display incorporated in the eye-wearable device at a wearer's perspective; and Automatically convey an adjustment prompt to the wearer to change the lateral spacing between the frame of the eye-wearable device and the wearer's head.

21. The method according to claim 16, wherein, the device management actions include: identifying the frequency with the maximum loss, which is the frequency at which the signal loss between the feed loop and the response loop in the target frequency band is the greatest; and estimating a current value of the wearer's head size based on the frequency with the maximum loss of the response signal; wherein, the device management actions include: identifying, based on the current head size value, a specific sub-part of the available display area provided by a near-eye display integrated in the eye-wearable device for activation; and autonomously activating the specific sub-part of the available display area of the near-eye display so as to adjust the display position of the near-eye display based on the wearer's head size.

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