Patent Description:
In various types of portable electronic devices, it can be challenging to sufficiently dissipate heat that is generated by on-board electronics and/or the power supply (e.g., batteries). Moreover, some thermal dissipation components may experience high mechanical loading conditions that can cause cyclic or other mechanical stresses and/or failure. It can be desirable to improve the dissipation of heat in electronic devices, and/or to improve the mechanical performance of such devices.

For example, modem computing and display technologies have facilitated the development of systems for virtual reality and/or augmented reality experiences, wherein digitally reproduced images or portions thereof are presented to a user in a manner wherein they seem to be, or may be perceived to be, real. A virtual reality, or "VR", scenario typically involves presentation of digital or virtual image information without transparency to other actual real-world visual input; an augmented reality, or "AR", scenario typically involves presentation of digital or virtual image information as an augmentation to visualization of the actual world around the user.

Some VR or AR systems may include portable electronic devices that may be subject to the thermal and/or mechanical loads. Accordingly, there remains a continuing need for improved thermal and/or mechanical solutions for portable electronic devices, including those used in conjunction with VR or AR systems.

<CIT> discloses a camera system comprising a housing comprising a first compartment of a lightning device in which a first electronic component is disposed; a second compartment of a camera in which a second electronic component is disposed, one or both of the first and second electrical components electrically communicating with another component of the electronic device; a fan assembly disposed in the first compartment, and a connection portion extending between the first and second compartments, the connection portion comprising a channel providing fluid communication between the first and second compartments, wherein the first compartment is separated from the second compartment at a location spaced away from the connection portion by a gap to provide thermal separation between the first and second electronic components. This teaching is however specifically directed to a digital camera or video camera.

<CIT> discloses a wearable electronic device, the wearable electronic device comprising:a housing configured to be worn by a user,wherein the wearable electronic device is a local processing and data module of an augmented reality system; and wherein the wearable electronic device further comprises a connector configured to connect to a headpiece of the augmented reality system that is to be worn by a user in combination with the wearable electronic device.

The invention is directed to a wearable electronic device according to claim <NUM>.

Neither this summary nor the following detailed description purports to define or limit the scope of the invention which is defined by the appended claims.

Throughout the drawings, reference numbers may be re-used to indicate correspondence between referenced elements. The drawings are provided to illustrate example embodiments described herein and are not intended to limit the scope of the disclosure.

Various embodiments disclosed herein relate to a wearable electronic device of an augmented reality system. For example, in <FIG> an augmented reality scene <NUM> is depicted wherein a user of an AR technology sees a real-world park-like setting <NUM> featuring people, trees, buildings in the background, and a concrete platform <NUM>. In addition to these items, the user of the AR technology also perceives that he "sees" a robot statue <NUM> standing upon the real-world platform <NUM>, and a cartoon-like avatar character <NUM> flying by which seems to be a personification of a bumble bee, even though these elements <NUM>, <NUM> do not exist in the real world. At least the elements <NUM>, <NUM> can be provided to the user at least in part by the portable (e.g., wearable) electronic devices disclosed herein. As it turns out, the human visual perception system is very complex, and producing a VR or AR technology that facilitates a comfortable, natural-feeling, rich presentation of virtual image elements amongst other virtual or real-world imagery elements is challenging.

For instance, head-worn AR displays (or helmet-mounted displays, or smart glasses) typically are at least loosely coupled to a user's head, and thus move when the user's head moves. If the user's head motions are detected by the display system, the data being displayed can be updated to take the change in head pose into account.

As an example, if a user wearing a head-worn display views a virtual representation of a three-dimensional (3D) object on the display and walks around the area where the 3D object appears, that 3D object can be re-rendered for each viewpoint, giving the user the perception that he or she is walking around an object that occupies real space. If the head-worn display is used to present multiple objects within a virtual space (for instance, a rich virtual world), measurements of head pose (e.g., the location and orientation of the user's head) can be used to re-render the scene to match the user's dynamically changing head location and orientation and provide an increased sense of immersion in the virtual space.

In AR systems, detection or calculation of head pose can facilitate the display system to render virtual objects such that they appear to occupy a space in the real world in a manner that makes sense to the user. In addition, detection of the position and/or orientation of a real object, such as handheld device (which also may be referred to as a "totem"), haptic device, or other real physical object, in relation to the user's head or AR system may also facilitate the display system in presenting display information to the user to enable the user to interact with certain aspects of the AR system efficiently. As the user's head moves around in the real world, the virtual objects may be re-rendered as a function of head pose, such that the virtual objects appear to remain stable relative to the real world. At least for AR applications, placement of virtual objects in spatial relation to physical objects (e.g., presented to appear spatially proximate a physical object in two- or three-dimensions) may be a non-trivial problem. For example, head movement may significantly complicate placement of virtual objects in a view of an ambient environment. Such is true whether the view is captured as an image of the ambient environment and then projected or displayed to the end user, or whether the end user perceives the view of the ambient environment directly. For instance, head movement will likely cause a field of view of the end user to change, which will likely require an update to where various virtual objects are displayed in the field of the view of the end user. Additionally, head movements may occur within a large variety of ranges and speeds. Head movement speed may vary not only between different head movements, but within or across the range of a single head movement. For instance, head movement speed may initially increase (e.g., linearly or not) from a starting point, and may decrease as an ending point is reached, obtaining a maximum speed somewhere between the starting and ending points of the head movement. Rapid head movements may even exceed the ability of the particular display or projection technology to render images that appear uniform and/or as smooth motion to the end user.

Head tracking accuracy and latency (e.g., the elapsed time between when the user moves his or her head and the time when the image gets updated and displayed to the user) have been challenges for VR and AR systems. Especially for display systems that fill a substantial portion of the user's visual field with virtual elements, it is advantageous if the accuracy of head-tracking is high and that the overall system latency is very low from the first detection of head motion to the updating of the light that is delivered by the display to the user's visual system. If the latency is high, the system can create a mismatch between the user's vestibular and visual sensory systems, and generate a user perception scenario that can lead to motion sickness or simulator sickness. If the system latency is high, the apparent location of virtual objects will appear unstable during rapid head motions.

In addition to head-worn display systems, other display systems can benefit from accurate and low latency head pose detection. These include head-tracked display systems in which the display is not worn on the user's body, but is, e.g., mounted on a wall or other surface. The head-tracked display acts like a window onto a scene, and as a user moves his head relative to the "window" the scene is re-rendered to match the user's changing viewpoint. Other systems include a head-worn projection system, in which a head-worn display projects light onto the real world.

Additionally, in order to provide a realistic augmented reality experience, AR systems may be designed to be interactive with the user. For example, multiple users may play a ball game with a virtual ball and/or other virtual objects. One user may "catch" the virtual ball, and throw the ball back to another user. In another embodiment, a first user may be provided with a totem (e.g., a real bat communicatively coupled to the AR system) to hit the virtual ball. In other embodiments, a virtual user interface may be presented to the AR user to allow the user to select one of many options. The user may use totems, haptic devices, wearable components, or simply touch the virtual screen to interact with the system.

Detecting head pose and orientation of the user, and detecting a physical location of real objects in space enable the AR system to display virtual content in an effective and enjoyable manner. However, although these capabilities are key to an AR system, but are difficult to achieve. In other words, the AR system can recognize a physical location of a real object (e.g., user's head, totem, haptic device, wearable component, user's hand, etc.) and correlate the physical coordinates of the real object to virtual coordinates corresponding to one or more virtual objects being displayed to the user. This generally requires highly accurate sensors and sensor recognition systems that track a position and orientation of one or more objects at rapid rates. Current approaches do not perform localization at satisfactory speed or precision standards.

Thus, there is a need for a better localization system in the context of AR and VR devices. Moreover, the continual and/or rapid movement of users can introduce various other problems into the electrical, thermal, and/or mechanical systems of such AR and/ VR devices.

Referring to <FIG>, some general componentry options are illustrated. In the portions of the detailed description which follow the discussion of <FIG>, various systems, subsystems, and components are presented for addressing the objectives of providing a high-quality, comfortably-perceived display system for human VR and/or AR.

As shown in <FIG>, an AR system user <NUM> is depicted wearing head mounted component <NUM> featuring a frame <NUM> structure coupled to a display system <NUM> positioned in front of the eyes of the user. A speaker <NUM> is coupled to the frame <NUM> in the depicted configuration and positioned adjacent the ear canal of the user (in one embodiment, another speaker, not shown, is positioned adjacent the other ear canal of the user to provide for stereo / shapeable sound control). The display <NUM> is operatively coupled <NUM>, such as by a wired lead or wireless connectivity, to a local processing and data module <NUM> which may be mounted in a variety of configurations, such as fixedly attached to the frame <NUM>, fixedly attached to a helmet or hat <NUM> as shown in the embodiment of <FIG>, embedded in headphones, removably attached to the torso <NUM> of the user <NUM> in a backpack-style configuration as shown in the embodiment of <FIG>, or removably attached to the hip <NUM> of the user <NUM> in a belt-coupling style configuration as shown in the embodiment of <FIG>.

The local processing and data module <NUM> may comprise a power-efficient processor or controller, as well as digital memory, such as flash memory, both of which may be utilized to assist in the processing, caching, and storage of data a) captured from sensors which may be operatively coupled to the frame <NUM>, such as image capture devices (such as cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, radio devices, and/or gyros; and/or b) acquired and/or processed using the remote processing module <NUM> and/or remote data repository <NUM>, possibly for passage to the display <NUM> after such processing or retrieval. The local processing and data module <NUM> may be operatively coupled <NUM>, <NUM>, such as via a wired or wireless communication links, to the remote processing module <NUM> and remote data repository <NUM> such that these remote modules <NUM>, <NUM> are operatively coupled to each other and available as resources to the local processing and data module <NUM>.

In one embodiment, the remote processing module <NUM> may comprise one or more relatively powerful processors or controllers configured to analyze and process data and/or image information. In one embodiment, the remote data repository <NUM> may comprise a relatively large-scale digital data storage facility, which may be available through the internet or other networking configuration in a "cloud" resource configuration. In one embodiment, all data is stored and all computation is performed in the local processing and data module, allowing fully autonomous use from any remote modules.

<FIG> is a schematic front plan view of the local processing and data module <NUM>, according to the invention. <FIG> is a schematic right side view of the local processing and data module <NUM> of <FIG>. As shown in <FIG>, the local processing and data module <NUM> can comprise a housing <NUM> comprising a first enclosure <NUM> and a second enclosure <NUM> mechanically connected with the first enclosure <NUM>. The second enclosure <NUM> is fluidly coupled with the first enclosure <NUM>. The first enclosure <NUM> and the second enclosure <NUM> are coupled to provide thermal isolation or separation therebetween, e.g., a gap (such as an air gap) between the enclosures <NUM>, <NUM> can provide improved thermal isolation therebetween. According to the invention, the first enclosure comprises a first compartment separated from a second compartment of the second enclosure <NUM> at a location spaced away from the first compartment by a gap that provides thermal separation between the first and second enclosures <NUM>, <NUM>. As discussed further below, however, in various embodiments at least some heat generated in the second enclosure <NUM> can flow to the first enclosure <NUM>.

The first enclosure <NUM> can comprise a front side <NUM> and a back side <NUM> opposite the front side <NUM>. The second enclosure <NUM> can be coupled with the back side <NUM> of the first enclosure. A connection portion comprising a channel <NUM> extends between the first and second enclosures <NUM>, <NUM>. The channel <NUM> of the connection portion connects an internal chamber or cavity defined within the first enclosure <NUM> with an internal chamber or cavity defined within the second enclosures <NUM>. As explained herein, in some embodiments, the channel <NUM> can be sized to accommodate one or more electrical connectors extending between components within the first and second enclosures <NUM>, <NUM>. Moreover, the channel <NUM> provides heat transfer by fluid communication or other means between the first and second enclosures <NUM>, <NUM>, e.g., to improve heat dissipation within the housing <NUM>. In the embodiment of <FIG>, each enclosure <NUM>, <NUM> can comprise a disc-shaped structure having an internal chamber or cavity shaped to contain various electronic devices, thermal mitigation features, and/or power supply devices. In other embodiments, the enclosures <NUM>, <NUM> can be shaped differently.

<FIG> is a schematic rear plan view of the local processing and data module <NUM> shown in <FIG>. As shown in <FIG>, the housing <NUM> (e.g., on a periphery of the first enclosure <NUM>) can include one or a plurality of user interfaces <NUM> configured to enable the user to control the operation of the system. For example, in some embodiments, the user interfaces <NUM> can comprise buttons or other types of interfaces to control the volume of the AR or VR experience, and/or to mute the volume. Other control mechanisms are possible through the interfaces <NUM>. In addition, the local processing and data module <NUM> includes one or more input/output (I/O) ports <NUM> to provide input and/or output data. For example, the I/O port(s) <NUM> can comprise an audio port.

Also, the local processing and data module <NUM> can comprise one or more inlet ports 104a, 104b configured to permit gas (e.g., air) to enter the housing <NUM>, e.g., at a position on a periphery of the first enclosure <NUM>. The local processing and data module <NUM> can also include one or more exhaust ports <NUM> to permit the gas (e.g., air) to exit the housing <NUM>, e.g., at a position on a periphery of the first enclosure <NUM>. Thus, air can flow into the enclosure <NUM> through the inlet ports 104a, 104b, and can exit the enclosure <NUM> through the exhaust port(s) <NUM>. The ports 104a, 104b, can include one or an array of holes in the enclosure <NUM> at spaced apart locations on the periphery of the enclosure <NUM>. The ports <NUM> can include one or an array of holes in the enclosure <NUM>. As discussed further below, one fan outlet is provided in some embodiments and in such embodiments a single ports <NUM> can be provided for fluid communication out of the housing <NUM>. The ports <NUM> can be disposed on multiple peripheral sides of the enclosure <NUM> in some embodiments. The ports <NUM> can be disposed on multiple peripheral sides of the enclosure <NUM>. As explained herein, the airflow through the enclosure <NUM> can beneficially carry heat away from the local processing and data module <NUM>.

<FIG> is a schematic side cross-sectional view of the local processing and data module <NUM> shown in <FIG>. As explained above, the local processing and data module <NUM> includes one or multiple electronic components <NUM> (illustrated schematically herein in block form), such as processors, memory dies, sensors, etc. In the embodiment of <FIG>, the electronic components <NUM> can be disposed within a chamber or first compartment of the first enclosure <NUM> of the housing. As shown, the electronic components <NUM> can be arranged within a relatively low profile and a relatively small lateral footprint. The illustrated electronic components <NUM> are shown at or near the front side <NUM> of the first enclosure <NUM>, but it should be appreciated that additional electronic components may be provided anywhere suitable in the enclosures <NUM>, <NUM>.

Incorporating multiple electronic components <NUM> within the enclosure <NUM> may generate substantial heat, which if not adequately cooled, may be uncomfortable to the user and/or may damage system components. Accordingly, a thermal mitigation assembly <NUM> can be provided in the housing (e.g., in the first enclosure <NUM>) to remove heat generated by the electronic components <NUM> and to maintain the temperature of the housing at comfortable and/or effective levels during operation. In the illustrated embodiment, the thermal mitigation assembly <NUM> is disposed rear of the electronic components <NUM>. In the view depicted in <FIG>, the thermal mitigation assembly <NUM> according to the invention comprises a fan assembly <NUM>, and can comprise a first heat spreader <NUM> disposed on a first side of a fan assembly <NUM>. The first heat spreader <NUM> can be disposed on a front side of the fan assembly <NUM> and thus is sometimes a front heat spreader. As explained herein, the first heat spreader <NUM> can be mechanically and thermally coupled with the electronic components <NUM>, so as to thermally conduct heat to a heat sink discussed below or components of the fan assembly <NUM>. The fan assembly <NUM> can blow or draw air near or over the heat spreader <NUM> to expel a heat transfer medium (e.g., the heated air or other heated gas) out of the local processing and data module <NUM> through the exhaust port <NUM>.

The local processing and data module <NUM> may also include additional electronic components (e.g., an on-board power supply module <NUM>) within the second enclosure <NUM> to provide power to the electronic components <NUM> in the first enclosure <NUM> such that the user need not be tethered to a wired power supply. The power supply <NUM> shown in <FIG> can, for example, include one or a plurality of batteries. The on-board power supply may generate additional heat within the local processing and data module <NUM>. The fan assembly <NUM> draws a heat transfer medium (e.g., heated air or other heated gas) from the second enclosure <NUM> into the first enclosure <NUM> by way of the channel <NUM> that provides fluid communication between the enclosures <NUM>, <NUM>. Thus, in various embodiments, the thermal mitigation assembly <NUM> can be configured to remove heat that is generated from one or both of the battery (e.g., the power supply <NUM>) and the electronic components <NUM>. In various embodiments, a majority of the heat removed from the local processing and data module <NUM> can comprise heat generated by the electronic components <NUM>.

<FIG> is a schematic perspective, exploded view of the first enclosure <NUM> of the local processing and data module <NUM>, according to one embodiment. As explained above in connection with <FIG>, the electronics components <NUM> can be positioned within the enclosure <NUM> forward of the thermal mitigation assembly <NUM>. The enclosure <NUM> can be structurally bounded or contained by connecting or mating a front cover 108a with a rear cover 108b. The front and rear covers 108a, 108b when connected define the chamber or first compartment in which the electronics components <NUM> and the thermal mitigation assembly <NUM> are disposed. Although <FIG> illustrates electronics components <NUM> and the thermal mitigation assembly <NUM> within the enclosure <NUM>, it should be appreciated that additional components may be provided in the first enclosure <NUM>.

As shown in <FIG>, the thermal mitigation assembly <NUM> can comprise a base <NUM> to support various components of the thermal mitigation assembly <NUM>. For example, as shown in <FIG>, the first heat spreader <NUM> and a thermal conveyance pathway <NUM> (e.g., a heat pipe) can be mounted to or coupled with the base <NUM>. In some embodiments, however, the assembly <NUM> may not include a base <NUM>, such that the first heat spreader <NUM> and the thermal conveyance pathway <NUM> may be disposed adjacent to or otherwise connected to the fan assembly <NUM>. In addition, a heat sink <NUM> (e.g., a finned stack of metallic plates or elements) can be mounted to or coupled with the base <NUM>. For example, the heat sink <NUM> can comprise linked copper fin patterns, with each fin having a thickness in a range of <NUM> to <NUM>, e.g., in a range of <NUM> to <NUM> (about <NUM> in some embodiments). The fins can be spaced in a range of <NUM> to <NUM>, or in a range of <NUM> to <NUM> (about <NUM> in some embodiments). A second heat spreader <NUM> can be disposed on a second side of the fan assembly <NUM>. The second heat spreader <NUM> can be disposed on a rear side of the fan assembly <NUM> and thus is sometimes a rear heat spreader. The first heat spreader <NUM> can be thermally and, optionally, mechanically coupled to some or all of the electronic components <NUM> by way of any suitable connector, such as a thermally conductive connector, a thermal gap pad, a thermal adhesive, etc. For example, in some embodiments, heat generated by the electronic components <NUM> may be conducted to the first heat spreader <NUM> by way of one or more thermal gap pads, which can comprise a thermally conductive elastomer. The thermal gap pads can generate pressure between the heat spreader <NUM> and the components so as to improve thermal conductivity. The heat can be conveyed from the heat spreader <NUM> and/or from the electronic components <NUM> along the thermal conveyance pathway <NUM> to the heat sink <NUM>.

The fan assembly <NUM> can drive or draw air over and/or around the first heat spreader <NUM>, the thermal conveyance pathway <NUM>, and/or the second heat spreader <NUM> to cool the first enclosure <NUM> and/or the second enclosure <NUM>. For example, influent air A1 can be drawn, by the fan assembly <NUM>, into the first enclosure <NUM> by way of the inlet ports 104a, 104b. The fan assembly <NUM> can circulate cooling air A2 within the first enclosure <NUM> and over and/or around the electronic components <NUM> to cool the electronic components <NUM>. The cooling air A2 may comprise ambient air drawn into the enclosure <NUM> without additional cooling in some embodiments. Moreover, as shown in <FIG>, the fan assembly <NUM> can draw cooling air A3 into the first enclosure <NUM> from the second enclosure <NUM>, e.g., by way of the channel <NUM>. Thus, in the illustrated embodiment, the electronic components <NUM> can be cooled by the cooling air A2 circulated within the enclosure <NUM>.

In some embodiments, the battery or power supply <NUM> may also be cooled by way of the cooling air A3 drawn from the second enclosure <NUM> into the first enclosure <NUM>. Heat from the second enclosure <NUM> can also be conducted by a thermal conductor into the first enclosure <NUM> in some embodiments and dissipated by the airflow described herein. The connection portion including the channel <NUM> comprises a thermal insulating gap so as to mitigate or reduce the flow of heat from the first enclosure <NUM> to the second enclosure <NUM> (or vice versa). The cooling air currents A2 and A3 can be drawn or sucked into an airflow opening <NUM> formed in an interior portion (e.g., central portion) of the fan assembly <NUM>. In some embodiments, for example, the cooling air A2 can pass laterally between the first heat spreader <NUM> or the base <NUM> and the fan assembly <NUM>, and can enter the fan assembly <NUM> through the opening <NUM>. As explained herein (see <FIG> and <FIG>), the air drawn through the airflow opening <NUM> of the fan assembly <NUM> can be expelled radially outward through an outlet air opening <NUM> in an outflow air current A4 from the fan assembly <NUM>. Thus, in various embodiments, air pathways of the fan assembly <NUM> can extend between the airflow opening <NUM> disposed along the longitudinal axis L and the outlet airflow opening <NUM> having a face disposed about an axis non-parallel to the longitudinal axis L. For example, the outlet airflow opening <NUM> can be disposed radially outward (e.g., generally perpendicular to the longitudinal axis L). The radially outflowing air current A4 can be directed over the heat sink <NUM> to drive thermal energy stored in the heat sink <NUM> out of the enclosure <NUM>. As shown in <FIG>, expelled air A5 can be directed out of the first enclosure <NUM> through the exhaust port <NUM> to the outside environs.

<FIG> is a schematic perspective, exploded view of the local processing and data module <NUM>, according to another embodiment. Unless otherwise noted, the local processing and data module <NUM> of <FIG> may be similar to the local processing and data module <NUM> of <FIG>. Unlike the embodiment of <FIG>, in <FIG>, only a single inlet port <NUM> and a single exhaust port <NUM> are shown. Thus, it should be appreciated that any suitable number of inlet ports <NUM> and/or outlet ports <NUM> may be provided for intaking air into the enclosure <NUM> and for expelling air from the enclosure <NUM>.

<FIG> is a schematic perspective, partially exploded view of the fan assembly <NUM> mounted to the first heat spreader <NUM>. <FIG> is a schematic, partially exploded view of the fan assembly <NUM>, the heat spreader <NUM>, the thermal conveyance pathway <NUM>, and the heat sink <NUM>. As shown in <FIG>, the electronic components <NUM> can be disposed near the front cover 108a. The first heat spreader <NUM> can be disposed rear of the electronic components, and the fan assembly <NUM> can be thermally coupled with, and disposed rear of, the first heat spreader <NUM>. The first heat spreader <NUM> can be disposed between the electronic components <NUM> and the fan assembly <NUM>. The fan assembly <NUM> can be thermally coupled with the first heat spreader <NUM>. In some embodiments, a gap may be disposed between the fan assembly <NUM> and the heat spreader <NUM> or base <NUM> to permit air to enter the opening <NUM>. The base <NUM> and thermal conveyance pathway <NUM> are obscured in <FIG>, since the base <NUM> and conveyance pathway <NUM> may be disposed between the heat spreader <NUM> and the fan assembly <NUM>. As explained above in connection with <FIG>, the outflow air current A5 can pass over the heat sink <NUM> (obscured in <FIG>) disposed near (e.g., upstream of) the outlet opening <NUM> of the fan assembly <NUM>.

As shown in <FIG>, the fan assembly <NUM> comprises a rotational axis L and a transverse axis T disposed non-parallel relative to (e.g., perpendicular to) the axis L. The rotational axis L is a longitudinal axis of a shaft assembly or a shaft portion about which a portion of the fan assembly <NUM> rotates and thus is sometimes referred to as a longitudinal axis L. The cooling air currents A2 (see <FIG>) and A3 (see <FIG> and <FIG>) can enter the fan assembly <NUM> through the airflow opening <NUM> from heat source(s) in the housings <NUM>, <NUM>, e.g., from the electronic components <NUM> and the power supply <NUM>, respectively. In some arrangements, for example, the air currents A2 can pass between the heat spreader <NUM> or the base <NUM> and the fan assembly <NUM>, and can enter the opening <NUM>. The cooling air currents A2, A3 can have velocity components aligned along the longitudinal axis L, at least locally in the vicinity of the opening <NUM> and at a corresponding opening on the opposite side of the fan assembly <NUM>. The rotation of the blades of the fan assembly <NUM> can therefore draw air into the fan assembly <NUM> with high momentum along the longitudinal axis. The outflow air current A4 can be directed radially outward through the outlet opening <NUM>, such that the air current A4 includes velocity components aligned along the transverse axis T. The outflow air current A4 can exit the enclosure <NUM> by way of the exhaust port <NUM> (see <FIG>).

<FIG> illustrates a heat map of the assembled heat spreader, thermal conveyance pathway <NUM>, and heat sink <NUM> during operation of the fan assembly <NUM>. The heat map was computed using computational fluid dynamics (CFD) software. As shown in <FIG> and <FIG>, the thermal conveyance pathway <NUM> can be coupled with the heat spreader <NUM>, e.g., disposed in a groove or channel of the heat spreader <NUM>. The heat spreader <NUM> can comprise a thermally conductive material, such as copper. The thermal conveyance pathway <NUM> can comprise a heat pipe comprising a thermally conductive channel. A working fluid (e.g., water) can be provided within a lumen of the thermal conveyance pathway <NUM>. In various embodiments, the heat pipe of the conveyance pathway <NUM> can comprise a copper pipe that is flattened so as to have a cross-sectional profile that is generally elliptical. In various embodiments, for example, a major dimension of the heat pipe can be between two and ten times larger than a minor dimension of the heat pipe (e.g., between five and nine times larger).

As shown in <FIG>, thermal energy Q can be stored in and/or conducted to the heat spreader <NUM> from the components <NUM>. The thermal energy Q from the heat spreader <NUM> can be transferred to the heat sink <NUM> along one or more thermal pathways Q1, Q2. For example, as shown in <FIG>, some thermal energy can be conveyed along a first pathway Q1 from the heat spreader <NUM> by way of the thermal conveyance pathway <NUM>. By utilizing a working fluid with a high heat capacity inside a thermally conductive tubular member, thermal energy can be rapidly and effectively transferred to the heat sink <NUM>. A second pathway Q2 can convey thermal energy along the area of the heat spreader <NUM> to the heat sink. As shown in <FIG>, the arrows representative of the first pathway Q1 are wider than the arrows representative of the second pathway Q2, indicating that heat is more efficiently and/or rapidly transferred along the first pathway Q1 than the second pathway Q2. In various embodiments, the conveyance pathway <NUM> can be significantly more thermally conductive than the first heat spreader <NUM> (e.g., at least five times, or at least ten times as thermally conductive as the heat spreader <NUM>).

As shown in <FIG>, during operation of the fan assembly <NUM>, heat can be rapidly transferred away from the heat sink by the outflow air current A4, as shown by the relatively cool temperatures maintained by the airflow over the heat sink <NUM>. Maintaining the heat sink <NUM> at a cool temperature can increase the thermal gradient between the heat spreader <NUM> and/or the thermal conveyance pathway <NUM> and the heat sink <NUM>. Beneficially, the disclosed embodiments can maintain the temperature of the local processing and data module <NUM> at suitably low temperatures.

<FIG> is a schematic side cross-sectional view of a fan assembly <NUM> that can be used in conjunction with the local processing and data module <NUM> described herein. The fan assembly <NUM> can comprise a support frame <NUM> configured to provide structural support to the fan assembly <NUM>. The frame <NUM> can comprise multiple frame portions connected together by, e.g., fasteners or other mechanical connectors. In other embodiments, the frame <NUM> can comprise a unitary body. A motor <NUM> can be mechanically coupled with the frame <NUM>. A shaft assembly <NUM> can be connected to the motor <NUM> and can extend along the longitudinal axis L described above, such that the longitudinal axis extends between and/or through first and second ends of the shaft assembly <NUM>. In the embodiment of <FIG>, in which the shaft assembly <NUM> is connected to the motor <NUM>, the shaft-supporting motor <NUM> may be considered part of the support frame <NUM> or frame assembly. In the illustrated arrangement, the shaft assembly <NUM> is cantilevered relative to the motor <NUM> or the frame <NUM>. As explained herein, the shaft assembly <NUM> can comprise a single shaft in some embodiments. In other embodiments, the shaft assembly <NUM> can comprise a plurality of shafts coupled together. A bearing <NUM>, which can be a bushing, can be disposed at least partially around the shaft assembly <NUM>. An impeller <NUM> can be operably coupled with and disposed about the bushing or other bearing <NUM>.

In some embodiments, the motor <NUM> can comprise a stator (not shown) having one or more wire coils that, when energized by electric power, create changing or alternating magnetic fields sufficient to drive a magnetic rotor assembly (not shown) coupled or formed with the impeller <NUM> (e.g., in or on a hub or other central portion of the impeller <NUM>). The magnetic fields generated by the motor <NUM> can interact with the magnetic rotor assembly of the impeller <NUM> to cause the magnetic rotor, and therefore the impeller <NUM>) to rotate about the longitudinal axis L. In the illustrated embodiment, the shaft assembly <NUM> can be fixed to the motor <NUM>, or to the frame <NUM>. Thus, in the illustrated embodiment, the shaft assembly <NUM> may not rotate. In some embodiments, the bushing or other bearing <NUM> may be secured over or fixed to the shaft assembly <NUM>, and the impeller <NUM> can rotate relative to the bushing <NUM> and the shaft assembly <NUM>. In some embodiments the bushing or other bearing <NUM> may be secured or fixed to the impeller <NUM> and can rotate with the impeller <NUM> relative to the shaft assembly <NUM>. In other embodiments, it should be appreciated that the motor <NUM> can include internal stator and rotor assemblies that cause the shaft assembly <NUM> (or portion(s) thereof to rotate). In such arrangements, the impeller <NUM> can be rotationally fixed relative to, and can rotate with, the shaft assembly <NUM>.

The impeller <NUM> can be driven to rotate at high speeds in order to adequately remove thermal energy from the housing. For example, the impeller <NUM> can rotate at speeds between <NUM>,<NUM> rpm and <NUM>,<NUM> rpm, e.g., <NUM>,<NUM> rpm, or at higher speeds. As explained above, the local processing and data module <NUM> can be worn or otherwise carried by the user for VR or AR experiences. The user may often be moving while wearing the module <NUM> and therefore, the local processing and data module <NUM>, and the fan assembly <NUM> therein, may frequently be disposed at different angles relative to gravity g. However, in some cases, the fan assembly <NUM> may be disposed at an angle, or may move at sufficiently high acceleration, such that the torque resulting from transverse loads on the shaft assembly <NUM> causes the shaft assembly <NUM> to bend or flex by an angle P as shown in <FIG>. The deflection or bending of the shaft assembly <NUM> due to transverse loading conditions may cause the impeller <NUM> to contact or hit the interior surface of the frame <NUM>, which can cause undesirable noise and/or vibration within the local processing and data module <NUM>. Moreover, the frequent application of such external torques to the shaft assembly <NUM> may cause the shaft assembly <NUM> to wear or experience fatigues, which may damage the shaft assembly.

Accordingly, it can be desirable to reduce or eliminate noise and vibrations caused by the application of transverse loads (and the resulting torques) on the shaft assembly <NUM>, and to reduce or eliminate the effects of fatigue or wear. The embodiments disclosed herein can advantageously control the loading transverse to the longitudinal axis L shown in <FIG>. In some arrangements, for example, the shaft assembly <NUM> may be made sufficiently stiff so as to reduce the amount of deflection of the distal end of the shaft assembly <NUM>. In other arrangements, elements on the frame <NUM> can assist in preventing the impeller <NUM> and shaft assembly <NUM> from contacting the frame <NUM> or substantially deflecting. For example, in some embodiments, a frame portion <NUM>' of the frame disposed about the impeller <NUM> can comprise one or more magnets in alignment with corresponding magnet(s) in the impeller <NUM>. For example, the magnets in the frame portion <NUM>' and impeller can have like poles aligned so as to cause the impeller <NUM> to remain centered within the frame <NUM> or at least to oppose deflection of the impeller <NUM> toward the frame <NUM> on a transverse loading which may reduce or eliminate deflection of the shaft assembly <NUM>.

<FIG> is a rear plan view of a fan assembly <NUM>, according to various embodiments disclosed herein. <FIG> is a schematic side sectional view of the fan assembly <NUM> of <FIG>. Unless otherwise noted, the components shown in <FIG> and <FIG> may include components similar to like numbered components shown in <FIG>. As shown in <FIG> and <FIG>, the fan assembly <NUM> can comprise a frame assembly that can have a first support frame 322a and a second support frame 322b coupled to the first frame 322a. The connected first and second support frames 322a, 322b can define an enclosure or chamber. The impeller <NUM> can be disposed between the first and second support frames 322a, 322b, e.g., within the enclosure defined by the frames 322a, 322b. Thus, in the illustrated embodiment, the first and second support frames 322a, 322b can define a housing in which the impeller <NUM> is disposed. The impeller <NUM> of <FIG> and <FIG> can comprise a hub <NUM> and one or a plurality of blades <NUM> (e.g., fan blades) coupled with and/or extending from the hub <NUM>. The hub <NUM> can be coupled with the shaft assembly <NUM>. In some embodiments, a bushing can be disposed between the shaft assembly <NUM> and the hub <NUM>. As explained above, in some embodiments, the impeller <NUM> can rotate relative to the rotationally fixed shaft assembly <NUM>. In other embodiments, the impeller <NUM> can rotate with the rotating shaft assembly <NUM>.

As shown in <FIG>, a first end <NUM> of the shaft assembly <NUM> can be supported by or coupled with the first support frame 322a (e.g., to a support structure defined by or including the frame, to the motor, etc.) For example, in the embodiment of <FIG>, the first end <NUM> of the shaft assembly <NUM> can be secured to the first frame 322a at a first shaft support <NUM> of the first support frame 322a. In various embodiments, the first end <NUM> can be welded, glued, or press fit onto the frame 322a. The first shaft support <NUM> can comprise a portion of a structural body defined by the first support frame 322a. In other embodiments, the first support frame 322a can comprise the motor such that the first end <NUM> of the shaft assembly <NUM> is secured to the motor and the shaft support <NUM> comprises a portion of the motor. It should be appreciated that any suitable structure can be used as the shaft support <NUM> so as to secure the first end <NUM> of the shaft assembly <NUM>.

As explained above, it can be advantageous to control transverse loads applied to the shaft assembly <NUM> so as to reduce noise and vibrations, and to mitigate the risks of fatigue, wear, or excessive loading conditions. Accordingly, in the embodiment of <FIG> and <FIG>, a second support frame 322b can be provided to control transverse loading on the shaft assembly <NUM>. The second support frame 322b can be coupled with the first support frame 322a and can be disposed at or over a second end <NUM> of the shaft assembly <NUM> so as to control transverse loading at the second end <NUM> of the shaft assembly <NUM>. In <FIG> and <FIG>, the second support frame 322b can comprise a second shaft support <NUM> coupled with the second end <NUM> of the shaft assembly <NUM>. The second shaft support <NUM> can be rigidly attached to the second support frame 322b across at least a portion of the airflow opening <NUM>. In some embodiments, the second shaft support <NUM> can comprise a pin or other connector that rigidly attaches the second end <NUM> of the shaft assembly <NUM> to the frame 322b. In various embodiments, the second shaft support <NUM> (e.g., a pin) can be connected concentrically or axially relative to the axis L about which the shaft assembly <NUM>, the impeller <NUM> or both the shaft assembly <NUM> and the impeller rotate. Positioning the second shaft support <NUM> along or centered relative to the axis L can beneficially reduce deflections and improve the rotation of the impeller <NUM>.

In the embodiment of <FIG> and <FIG>, the second shaft support <NUM> can comprise or be connected with an elongate member <NUM> between first and second end portions 335a, 335b thereof. As shown in <FIG>, the first end portion 335a of the elongate member <NUM> can be supported at a first portion of the second support frame 322b, and the second end portion 335b of the elongate member <NUM> can be supported at a second portion of the second support frame 322b. The first and second end portions 335a, 335b (and the corresponding first and second portions of the second frame 322b) can be spaced apart about a periphery of the airflow opening <NUM>. In the illustrated embodiment, for example, the first and second end portions 335a, 335b (and the first and second portions of the frame 322b) can be disposed on generally opposite sides of the airflow opening <NUM>. In other embodiments, however, the first and second end portions 335a, 335b of the elongate member <NUM> can be spaced apart peripherally by less than <NUM>°. For example, the elongate member <NUM> may extend from the first end portion 335a over the airflow opening <NUM> and may connect with the second end <NUM> of the shaft assembly. The elongate member <NUM> may further extend from the second end <NUM> to the second end portion 335b at an angle less than <NUM>°.

Rigidly supporting the second end <NUM> of the shaft assembly <NUM>, in addition to supporting the first end <NUM>, can beneficially control transverse loading on the shaft assembly <NUM> and can reduce or eliminate deflections of the assembly <NUM>. However, since the elongate member <NUM> may be disposed across part of or the entire airflow opening <NUM>, the elongate member <NUM> may interfere with the influent air entering the fan assembly <NUM> through the airflow opening <NUM>. Accordingly, in the illustrated embodiment, the elongate member <NUM> can be angled relative to the transverse axis T by an angle A selected or determined so as to reduce or minimize disruption to the influent air (e.g., such that the airflow into the opening <NUM> is maximized or increased sufficiently for thermal design goals). For example, in some embodiments, computational techniques (such as computational fluid dynamics, or CFD) can calculate the estimate air flow field through the motor assembly <NUM>. The analysis or calculations can determine the desired angle A at which to orient the elongate member <NUM>. In various embodiments, the desired angle A can correspond to a global or local maximum of airflow when the impeller <NUM> is rotating, as compared over a range of angles A of the elongate member <NUM> (with the elongate member <NUM> being attached to the frame 322b). In some embodiments, computational techniques can be applied without the elongate member <NUM> to determine the locations of the opening <NUM> at which the airflow is less compared to other positions about the opening <NUM> during operation of the fan assembly <NUM>. If a minimum or reduced airflow region is found (without the elongate member <NUM> being attached), then the desired location or orientation of the elongate member <NUM> may correspond with these regions of lesser airflow. In the illustrated embodiment, it can be desirable to orient the elongate member <NUM> at a sufficiently small angle A relative to the transverse axis T, so that air can flow around the relatively thin profile of the elongate member <NUM> at such angles. In various embodiments, the angle A can be in a range of -<NUM>° to <NUM>°, e.g., in a range of -<NUM>° to <NUM>°. It should be appreciated, however, that other angles A may be used depending on the specific flow dynamics of the fan assembly <NUM>. Beneficially, in various embodiments, the manufacturer or assembler can accordingly assemble the fan assembly <NUM> and, based upon the determined lesser airflow regions during operation of the fan assembly <NUM> without the elongate member <NUM>, the manufacturer can position the elongate member <NUM> so as to minimize disruptions to airflow (e.g., by orienting the elongate member <NUM> over these minimal flow regions). Orienting the elongate member <NUM> during assembly and after calculation of minimal airflow patterns can enable the manufacturer or assembler to account for specific airflow patterns of the device being cooled before affixing the elongate member <NUM>.

As discussed further below, the orientation of the elongate member <NUM> can be generally transverse to the direction of locally greater or globally greatest airflow over the frame 322a and through the opening <NUM> (or through an opening in the frame 322b). The elongate member <NUM> can be oriented to have a minimal profile facing this greater or greatest airflow regime.

<FIG> illustrate various top and side profiles of the elongate member <NUM> described herein. For example, <FIG> is a schematic top plan view of an elongate member 325a having a generally straight profile along an x-y plane defined generally parallel with the rotational plane of the impeller <NUM>, e.g., the impeller <NUM> may rotate within a plane generally parallel to the x-y plane shown in <FIG> such that the x-y plane may be transverse to the rotational longitudinal axis L. <FIG> is a schematic top plan view of an elongate member 325b having a first curved region 361a and a second curved region 361b. In <FIG>, the first and second curved regions 361a, 361b may reverse the direction of curvature at or near a transition region <NUM>. For example, the transition region <NUM> can serve as an inflection region at which the first and second regions 361a, 361b change directions of curvature. Similarly, <FIG> is a schematic top plan view of an elongate member 325c having a first curved region 361a and a second curved region 361b, according to another embodiment. Unlike in <FIG>, in <FIG>, the first and second curved regions 361a, 361b can change the directions of curvature along a smooth or continuous inflection or transition region <NUM>. The shapes as shown from a top down view (e.g., along the x-y plane) may be selected so as to achieve a desired flow profile through the fan assembly.

<FIG> is a schematic side view of an elongate member 325d having a generally planar or straight profile, as viewed along an x-z plane defined generally transverse to the x-y plane, e.g., parallel to the direction of the longitudinal rotational axis L (see the x-z plane shown in <FIG>). <FIG> is a schematic side view of an elongate member 325e having a non-linear or shaped profile, as viewed along an x-z plane. For example, as shown in <FIG>, the elongate member 325e can comprise a first portion 362a disposed along a first location of the z-axis and a second portion 362b disposed offset from the first portion 362a along the z-axis (which may be parallel or generally aligned with the longitudinal axis L). A third transition portion 362c may serve to connect the first and second portions 362a, 362b.

<FIG> is a schematic side view of an elongate member 325f having a non-linear or curved profile, as viewed along an x-z plane, according to another embodiment. As with the embodiment of <FIG>, the elongate member 325f can comprise first portions 363a along a first location along the z-axis, and one or more second portions 363b at other locations along the z-axis. Unlike the embodiment of <FIG>, the member 325f of <FIG> can comprise curved surfaces along the z-axis. Thus, as shown in <FIG>, the shape of the elongate member <NUM> may vary within the x-y plane and/or within the x-z plane. The elongate members 325a-325f may accordingly be shaped to have any suitable type of three-dimensional profile for improving the flow through the fan assembly.

<FIG> is a rear plan view of a fan assembly <NUM>, according to another embodiment. Unless otherwise noted, the components shown in <FIG> may include components similar to like numbered components shown in <FIG>, with the reference numerals incremented by <NUM> relative to <FIG>. Unlike the embodiment of <FIG> and <FIG>, however, the elongate member <NUM> shown in <FIG> can have an airfoil shape so as to further improve airflow through the fan assembly <NUM>. In some embodiments, a thickness of the elongate member <NUM> can vary along a length of the elongate member <NUM> between the first and second end portions 435a, 435b. In some embodiments, a width of the elongate member <NUM> can vary along the length of the elongate member <NUM> between the first and second end portions 435a, 435b. In various embodiments, the width and/or thickness of the elongate member <NUM> can be selected to be sufficiently strong so as to support the shaft assembly <NUM> during the expected transverse loading conditions and to accommodate the induced stresses. Thus, the embodiment of <FIG> can also beneficially control transverse loading on the shaft assembly <NUM> while maintaining adequate airflow through the fan assembly <NUM>.

<FIG> is a schematic side sectional view of a fan assembly <NUM>, according to another embodiment. Unless otherwise noted, the components shown in <FIG> may include components similar to like numbered components shown in <FIG>, with the reference numerals incremented by <NUM> relative to <FIG>. For example, as with the embodiment of <FIG>, the fan assembly <NUM> can include the impeller <NUM> coupled with the shaft assembly <NUM> (e.g., by way of the bushing <NUM>). Moreover, as with <FIG>, the first end <NUM> of the shaft assembly <NUM> can be fixed or secured to the first frame 522a, for example, at the first shaft support <NUM> which may be disposed at or on the motor <NUM> or on a structural body defined by the frame 522a. In addition, as with <FIG>, the second end <NUM> of the shaft assembly <NUM> can be fixed or secured to the second frame 522b at the second shaft support <NUM>, which may also comprise the elongate member <NUM>. Beneficially, the first and second shaft supports <NUM> can control transverse loading on the shaft assembly <NUM> and can reduce deflections of the shaft assembly <NUM>. Moreover, as explained above, in some embodiments, the angular orientation of the elongate member <NUM> can be selected so as to improve airflow through the fan assembly <NUM> or in some cases to minimize the airflow cost of including the elongate member <NUM> in the air flow stream.

However, unlike the embodiments of <FIG>, in <FIG>, the shaft assembly <NUM> can comprise a first shaft portion 523a rotationally fixed (e.g., secured) to the first support frame 522a and a second shaft portion 523b rotationally fixed (e.g., secured) to the impeller <NUM>. As shown in <FIG>, the first end <NUM> of the shaft assembly <NUM> can be disposed on a first side of the impeller <NUM>, and the second end <NUM> of the shaft assembly <NUM> can be disposed on a second side of the impeller <NUM> that is opposite the first side. The second shaft portion 523b can be rotatable over and/or relative to a free end of the first shaft portion 523a. In some embodiments, the first and second shaft portions 523a, 523b can comprise two separate shafts that are connected together, e.g., at the impeller <NUM>. In some embodiments, the first and second shaft portions 523a, 523b can comprise a single shaft, with the first portion 523a on the first side of the impeller <NUM> and the second portion 523b on the second side of the impeller <NUM>.

Thus, in the embodiment of <FIG>, the first shaft portion 523a can be rotationally fixed relative to the first frame 522a (e.g., the motor <NUM> or a structural body of the frame 522a. The second shaft portion 523a can rotate with the impeller <NUM> and bushing <NUM>. As with the above embodiments, supporting the second end <NUM> of the shaft assembly <NUM> with the second frame 522b can beneficially control transvers loading conditions and reduce deflections of the shaft assembly <NUM>.

<FIG> is a schematic side sectional view of a fan assembly <NUM>, according to another embodiment. Unless otherwise noted, the components shown in <FIG> may include components similar to like numbered components shown in <FIG>, with the reference numerals incremented by <NUM> relative to <FIG>. For example, as with <FIG>, the first end <NUM> of the shaft assembly <NUM> can operably couple with the first frame 622a (which may comprise a structural body of the frame, the motor <NUM>, or any other suitable stationary feature of the fan assembly <NUM>. The second end <NUM> of the shaft assembly <NUM> can operably couple with the second frame 622b. In <FIG>, the impeller <NUM> and shaft assembly <NUM> are illustrated in a partially exploded view for ease of illustration. During operation, however, it should be appreciated that the first end <NUM> of the shaft assembly <NUM> engages with the first frame 622a, and the second end <NUM> of the shaft assembly <NUM> engages with the second frame 622b.

Moreover, as with <FIG>, the impeller <NUM> can be coupled with first and second shaft portions 623a, 623b of the shaft assembly <NUM>. The first and second shaft portions 623a, 623b can comprise a single unitary shaft, or the first and second shaft portions 623a, 623b can comprise two separate shafts. In the embodiment of <FIG>, the shaft portions 623a, 623b can be fixed to the impeller <NUM> so as to impart rotation to the impeller <NUM>. For example, a portion of the impeller hub <NUM> can include a follower magnet or rotor assembly. A stator assembly of the motor <NUM> can be energized so as to create magnetic forces on the hub <NUM> to impart rotation of the impeller <NUM>. In addition, as shown in <FIG>, a concave member comprising a first bushing 624a can be coupled or formed with the first frame 622a and/or the motor <NUM>. A second concave member comprising a second bushing 624b can be coupled or formed with the second frame 622b. The first bushing 624a can act as the first shaft support <NUM> to rotationally support the first end <NUM> of the shaft assembly <NUM>, and the second bushing 624b can act as or comprise the second shaft support <NUM> to rotationally support the second end <NUM> of the shaft assembly <NUM>. Thus, during rotation of the impeller <NUM>, the first end <NUM> of the first shaft portion 623a can rotate within the first bushing 624a. The second end <NUM> of the second shaft portion 623a can rotate within the second bushing 624b.

Beneficially, the second bushing 624b can assist in controlling the transverse loading on the shaft assembly <NUM> during operation of the fan assembly <NUM>. As shown, the second bushing 624b of the shaft support <NUM> can be aligned along or aligned concentrically relative to the second shaft portion 623b. In some embodiments, the second shaft support <NUM> can also comprise the elongate member <NUM> extending across part of or the entire airflow opening <NUM>. As shown in <FIG>, one or both of the first and second bushings 624a, 624b can comprise a concave member, e.g., a concave inner surface. In some embodiments, the concave inner surface may comprise or define a generally or substantially spherical surface. The concave inner surface defined in the first and/or second bushings 624a, 624b can beneficially permit rotation of the shaft assembly <NUM> while supporting both ends <NUM>, <NUM> of the shaft assembly <NUM> against transverse loading conditions. Moreover, the concave inner surfaces of the first and/or second bushings 624a, 624b can be shaped so as to accommodate small but acceptable rotation and/or translation of the ends <NUM>, <NUM> of the shaft assembly <NUM>. Accommodating such negligible movement of the ends <NUM>, <NUM> can further reduce stresses on the shaft assembly <NUM> while preventing undesirable large deformations.

<FIG> illustrate additional examples of a fan assembly that can be used in conjunction with the embodiments disclosed herein. For example, <FIG> is a schematic side view of a fan assembly <NUM> comprising a shaft assembly <NUM> that operably couples to an impeller assembly <NUM> by way of a bushing <NUM>. Unless otherwise noted, the components shown in <FIG> may include components similar to like numbered components shown in <FIG>, with the reference numerals incremented by <NUM> relative to <FIG>. In the embodiment of <FIG>, the shaft assembly <NUM> can comprise a single shaft that can be connected at its ends to frames 922a, 922b (e.g., welded to the elongate member <NUM> or frame 922b, mechanically fastened, or otherwise fixed). In some embodiments, one of the frames 922b can comprise the elongate member <NUM>. In <FIG>, the shaft assembly <NUM> can comprise a separate member from the bushing <NUM> and impeller <NUM>, e.g., the shaft assembly <NUM> of <FIG> may not be integrally formed with the bushing <NUM>. In <FIG>, the shaft assembly <NUM> may or may not be rotationally fixed to the bushing <NUM>. For example, in some embodiments, the shaft assembly <NUM> may not be rotationally fixed to the bushing <NUM> such that the bushing <NUM> and impeller <NUM> may rotate relative to (e.g., may rotate about) the fixed shaft assembly <NUM>. In other embodiments, the bushing <NUM> and impeller <NUM> may be rotationally fixed or coupled to the shaft assembly <NUM> such that the impeller <NUM> and bushing <NUM> rotate with or follow the rotation of the shaft assembly <NUM>.

<FIG> is a schematic side view of a fan assembly <NUM> comprising a shaft assembly <NUM> that operably couples to an impeller assembly <NUM> by way of a bushing <NUM>. Unless otherwise noted, the components shown in <FIG> may include components similar to like numbered components shown in <FIG>, with the reference numerals incremented by <NUM> relative to <FIG>. Unlike the embodiment of <FIG>, in the embodiment of <FIG>, the shaft assembly <NUM> may be physically integrated with the impeller <NUM> (and/or with a bushing, not shown) so as to define a single unitary shaft assembly and impeller. Thus, in <FIG>, the shaft assembly <NUM> can be fixed at its ends to the frames 1022a, 1022b (one of which may comprise an elongate member <NUM>). Rotation of the shaft assembly <NUM> can impart rotation to the integrally formed impeller <NUM>.

<FIG> is a schematic side view of a fan assembly <NUM> comprising a shaft assembly <NUM> having first and second shaft portions 1123a, 1123b operably coupled with the impeller <NUM>. Unless otherwise noted, the components shown in <FIG> may include components similar to like numbered components shown in <FIG>, with the reference numerals incremented by <NUM> relative to <FIG>. In the embodiment of <FIG>, the first and second shaft portions 1123a, 1123b can comprise separate shafts that are respectively coupled with the frames 1122a, 1122b. The first and second shaft portions 1123a, 1123b can connect to the impeller <NUM> by way of the hub <NUM>. In <FIG>, the first and second shaft portions 1123a, 1123b can be fixed to the frames 1122a, 1122b such that the impeller <NUM> and hub <NUM> rotate relative to the shaft portions 1123a, 1123b. In other embodiments, the first and second shaft portions 1123a, 1123b can be fixed to the hub <NUM> such that the hub <NUM> and impeller <NUM> can rotate with the first and second shaft portions 1123a, 1123b.

<FIG> is a schematic side view of a fan assembly <NUM> comprising a shaft assembly <NUM> having first and second shaft portions 1223a, 1223b operably coupled with the impeller <NUM>. Unless otherwise noted, the components shown in <FIG> may include components similar to like numbered components shown in <FIG>, with the reference numerals incremented by <NUM> relative to <FIG>. Unlike the embodiment of <FIG>, for example, the first shaft portion 1223a can be integrally formed with the first frame 1222a, e.g., the first shaft portion 1223a and the first frame 1222a can define a single unitary component such that the first shaft portion 1223a extends from the first frame 1222a. Similarly, the second shaft portion 1223b can be integrally formed with the second frame 1222b, e.g., the second shaft portion 1223b and the second frame 1222b can define a single unitary component such that the second shaft portion 1223b extends from the second frame 1222b. In some embodiments, the first and second shaft portions 1223a, 1223b can be fixed such that the hub <NUM> and impeller <NUM> rotate relative to the shaft portions 1223a, 1223b.

<FIG> is a plan view of flow patterns within a fan assembly <NUM> before an elongate member <NUM> is attached to the fan assembly <NUM>. <FIG> is a schematic perspective view of flow patterns within and around a fan assembly <NUM> after the elongate member <NUM> is placed at a desired orientation relative to the fan assembly <NUM>. The flow patterns of <FIG> were computed using computational fluid dynamics (CFD) techniques.

<FIG> represents the velocity field of cooling air currents A2, A3 (see <FIG>) that flow into the airflow opening <NUM> of the fan assembly <NUM>, without or before the elongate member <NUM> is attached. As explained above, the fan assembly <NUM> may be used in conjunction with various types of portable electronic devices, which may include different types or numbers of electronic components. Once the electronic device design has been completed, the flow patterns through the fan assembly <NUM> can be computed to determine the velocity field of the fan assembly <NUM> during operation and accounting for the electronic components within the housing. For the assembly <NUM> shown in <FIG> when used in conjunction with a local processing and data module <NUM>, the circumferential location Cmax representative of maximum or increased airflow can be determined. Similarly, the circumferential location Cmin representative of minimum or reduced airflow can be determined.

Based on the velocity profile determined for the fan assembly <NUM> without the elongate member <NUM>, the desired orientation of the elongate member <NUM> can be selected. In some cases, it may be desirable to orient the elongate member <NUM> to correspond to minimum airflow through the opening <NUM>. In some embodiments, one end portion of the elongate member <NUM> can be positioned at the circumferential location Cmin and the other end portion can be disposed at an opposite circumferential location. In some embodiments, the first and second end portions of the elongate member <NUM> can be positioned circumferentially based on a weighted average or other determinative criteria for minimum airflow. By positioning the elongate member <NUM> at regions of minimum or reduced airflow, the effect of the elongate member <NUM> on the airflow into the fan assembly <NUM> can be reduced or eliminated.

<FIG> illustrates the airflow pathways A2, A3 and their velocity profiles through the fan assembly <NUM> after the elongate member <NUM> is oriented according to the selections and determinations made in connection with <FIG>. As shown in <FIG>, the elongate member <NUM> does not appreciably reduce the airflow through the fan assembly <NUM>. Rather, the airflow pathways A2, A3 pass over the elongate member <NUM> with little or no loss of momentum.

<FIG> is a schematic back, left perspective view of an electronic device according to one embodiment. <FIG> is a schematic front, right perspective view of the electronic device of <FIG>. <FIG> is a schematic front plan view of the electronic device of <FIG>. <FIG> is a schematic back plan view of the electronic device of <FIG>. <FIG> is a schematic right side view of the electronic device of <FIG>. <FIG> is a schematic left side view of the electronic device of <FIG>. <FIG> is a schematic top plan view of the electronic device of <FIG>. <FIG> is a schematic bottom plan view of the electronic device of <FIG>.

The electronic device comprises the local processing and data module <NUM> described above. As explained above in connection with <FIG>, the local processing and data module <NUM> comprise a first enclosure <NUM> (which may be similar to the enclosure <NUM>) and a second enclosure <NUM> spaced from the first enclosure <NUM> by a gap <NUM>. As explained herein, one or more electronic devices (e.g., processor(s)) may be provided in a first compartment defined at least in part by the first enclosure <NUM>. One or more other electronic devices (e.g., one or more batteries, one or more processor(s), etc.) may be provided in a second compartment defined at least in part by the second enclosure <NUM>.

In various embodiments, it can be desirable to operate the electronic device at high speeds (e.g., at high speeds for central processing and/or graphics processing units), while also charging the power supply (e.g., battery(ies) of the electronic device). The battery(ies) disclosed herein can be any suitable type of battery, including, e.g., a lithium ion battery(ies). However it can be challenging to operate the processor(s) at high speeds (and corresponding high temperatures) while also charging and/or discharging the battery(ies). For example, in some embodiments, the processor(s) can operate up to about <NUM> before throttling back (e.g., before dynamic frequency scaling or throttling is started). Such high temperatures for processor operation may exceed the maximum temperature thresholds for effective battery usage (e.g., which may be at or near <NUM> in some embodiments). Thus, the temperature rise from operating the processor(s) at high speeds may reduce the ability to rapidly and effectively charge the battery(ies) during use of the electronic device (e.g., during high speed operation of the processor(s)). It should be appreciated that the processor and battery operating temperatures are schematic, and that the processor(s) and battery(ies) can be operated at various temperatures.

Accordingly, various embodiments disclosed herein utilize the first and second enclosures <NUM>, <NUM> in conjunction with a connection portion <NUM> to thermally separate the compartments of the enclosures <NUM>, <NUM>. For example, the processor(s) may be disposed in the first compartment of the first enclosure <NUM>, and may operate at high speeds and, therefore, high temperatures. The battery(ies) can be disposed in the second compartment of the second enclosure <NUM> and can electrically communicate with other components of the device, e.g., with the processor(s) in the first enclosure <NUM>. In some embodiments, one or more processing elements can be disposed in the first enclosure <NUM>, and one or more other processing elements can be disposed in the second enclosure <NUM>. In some embodiments the processing elements in both enclosures <NUM>, <NUM> can be used to control the operation of the system.

In some embodiments, the connection portion <NUM> can comprise the channel <NUM>, which may be similar to the channel <NUM> described above. In some embodiments, the connection portion <NUM> can comprise an air or thermal gap that separates the first and second enclosures <NUM>, <NUM>. The relatively low thermal conductivity of the air gap (and high thermal insulation properties) can serve to thermally separate the processor(s) in the first enclosure <NUM> from the battery(ies) in the second enclosure <NUM>. In some embodiments, one or more connectors or wires can pass through the channel <NUM> to electrically connect the processor(s) in the first enclosure <NUM> with the battery(ies) of the second enclosure <NUM>. Additional components may also be provided in the first and/or second enclosures <NUM>, <NUM>. Beneficially, therefore, the thermal gap provided by the connection portion <NUM> can reduce or substantially prevent heat from passing from the processor(s) in the first enclosure <NUM> to the battery(ies) in the second enclosure <NUM>. Thus, the processor(s) can operate at relatively high speeds and temperatures, while maintaining the battery(ies) at sufficiently low temperatures so as to enable charging during operation of the processor(s). By contrast, providing the battery(ies) and processor(s) within a single compartment or enclosure may not provide adequate heat separation between the battery(ies) and processor(s).

In the illustrated embodiment, the connection portion <NUM> comprises an air gap to provide thermal insulation between the first and second enclosures <NUM>, <NUM>. In other embodiments, other low thermal conductivity materials (such as insulators or dielectrics) may be provided in the connection portion <NUM>. For example, in some embodiments, a thermally insulating polymer (e.g., potting compound or encapsulant) may be provided in the connection portion <NUM>. In some embodiments, the first and second compartments defined by the first and second enclosures <NUM>, <NUM> may also be filled with a gas (e.g., air). In other embodiments, the electronic devices (e.g., processor(s), battery(ies), etc.) may also be encapsulated or otherwise enclosed within another type of insulating material, such as a polymer or dielectric.

Further, as shown in <FIG>, the first and second enclosures <NUM>, <NUM> are separated by a gap <NUM> (e.g., at a location spaced from or below the connection portion <NUM>) having a gap width G as shown in <FIG>, which may be similar or generally the same as the width or gap defined by the connection portion <NUM> disposed or extending between the first and second enclosures <NUM>, <NUM>. The gap <NUM> (e.g., an air gap between the enclosures <NUM>, <NUM>) can provide improved thermal separation between the first and second enclosures <NUM>, <NUM>. In some embodiments, a majority of the spaces between the compartments within first and second enclosures <NUM>, <NUM> may be filled with air or a gas. For example, the channel <NUM> can be filled with a gas in some embodiments, and the gap <NUM> between outer portions of the enclosures <NUM>, <NUM> can comprise a gas such as air. As shown, the channel <NUM> can have a side cross-sectional area that is smaller than a cross-sectional area of the first compartment of the first enclosure <NUM> (and/or smaller than the cross-sectional area of the second compartment of the second enclosure <NUM>), taken along a direction parallel to a maximum dimension of the first compartment.

The enclosures <NUM>, <NUM> can comprise a clip <NUM> disposed within the gap <NUM>. The clip <NUM> can comprise projection(s) extending from the first and second enclosures <NUM>, <NUM>. The clip <NUM> can improve wearability of the module <NUM>, e.g., on a belt or other clothing accessory of the user). In some embodiments, the gap width G of the connection portion <NUM> (e.g., the channel <NUM>) and/or the gap <NUM> may be in a range of <NUM> to <NUM>, in a range of <NUM> to <NUM>, or in a range of <NUM> to <NUM>. Providing a thermal gap or thermal barrier (e.g., air gap) may provide sufficient thermal separation between the enclosures <NUM>, <NUM>. In some embodiments, one or both of the enclosures <NUM>, <NUM> may be constructed of a material that has a relatively low thermal conductivity so as to further improve the thermal barrier between the internal compartments of the enclosures <NUM>, <NUM>. For example, in some embodiments, a lower thermal conductivity material (e.g., aluminum or plastic) may be used as compared with higher thermal conductivity materials. In various embodiments, as disclosed above, the thermal gap provided by the connection portion <NUM> and/or the gap <NUM> may still permit at least some heat flow from the first enclosure <NUM> to the second enclosure <NUM>. The fan assemblies disclosed herein can mitigate this heat transfer, however, so as to reduce heat dissipation from the first enclosure <NUM> to the second enclosure <NUM>.

<FIG> is a schematic heat transfer map <NUM> of a side view of the electronic device of <FIG> during operation of the electronic devices. <FIG> is a schematic top view of the heat transfer map <NUM>. As shown in <FIG>, the temperature profile of the first enclosure <NUM> (in which the processor(s) may be disposed) may be significantly higher than the temperature profile of the second enclosure <NUM> (in which the battery(ies) may be disposed), indicating that the connection portion <NUM> and/or the gap <NUM> provide adequate thermal separation between the enclosures <NUM>, <NUM>. Various embodiments can beneficially provide thermal separation between the enclosures <NUM>, <NUM> of at least <NUM>, at least <NUM>, etc..

In various embodiments disclosed herein, we, the inventors, have invented new, original and ornamental designs for an electronic device. In <FIG>, the shading shows contours and the broken lines are for illustrative purposes and form no part of the claimed design. <FIG> is a schematic back, left perspective view of an electronic device according to one embodiment of the present design. <FIG> is a schematic front, right perspective view of the electronic device of <FIG>. <FIG> is a schematic front plan view of the electronic device of <FIG>. <FIG> is a schematic back plan view of the electronic device of <FIG>. <FIG> is a schematic right side view of the electronic device of <FIG>. <FIG> is a schematic left side view of the electronic device of <FIG>. <FIG> is a schematic top plan view of the electronic device of <FIG>. <FIG> is a schematic bottom plan view of the electronic device of <FIG>. Various embodiments are accordingly directed to the ornamental designs for an electronic device, as shown and described herein, including at least in <FIG>.

The systems of the disclosure each have several innovative aspects, no single one of which is solely responsible or required for the desirable attributes disclosed herein.

Claim 1:
A wearable electronic device (<NUM>), the wearable electronic device comprising:
a housing (<NUM>) configured to be worn by a user (<NUM>), the housing (<NUM>) comprising:
a first compartment (<NUM>; <NUM>) in which a first electronic component (<NUM>) is disposed;
a second compartment (<NUM>; <NUM>) in which a second electronic component (<NUM>) is disposed, one or both of the first and second electronic components (<NUM>, <NUM>) electrically communicating with another component of the electronic device;
a fan assembly (<NUM>, <NUM>; <NUM>) disposed in the first compartment (<NUM>; <NUM>); and
a connection portion extending between the first and second compartments (<NUM>, <NUM>; <NUM>, <NUM>), the connection portion comprising a channel (<NUM>) providing fluid communication between the first and second compartments (<NUM>, <NUM>; <NUM>, <NUM>),
wherein the first compartment (<NUM>; <NUM>) is separated from the second compartment (<NUM>; <NUM>) at a location spaced away from the connection portion by a gap (<NUM>) to provide thermal separation between the first and second electronic components (<NUM>, <NUM>; <NUM>, <NUM>);
wherein the wearable electronic device is a local processing and data module of an augmented reality system; and
wherein the wearable electronic device further comprises a connector (<NUM>) configured to connect to a headpiece of the augmented reality system that is to be worn by a user in combination with the wearable electronic device.