Patent Description:
Cartilage conduction technology may involve exciting auricular cartilage located on an outer ear (sometimes referred to as the pinna) of a user. In such examples, the excitation of the cartilage may cause the cartilage to generate sound pressure that propagates through the user's ear canal toward the user's eardrum. Unfortunately, some cartilage conduction technologies may have certain drawbacks and/or design tradeoffs that give rise to one or more deficiencies. In other words, such cartilage conduction technologies may fail to provide a solution that addresses certain competing goals and/or objectives (e.g., high audio performance versus high user comfort).

For example, a cartilage conduction system may include a transducer that generates mechanical energy and an interface that couples the transducer to the outer ear of a user. Document <CIT> and document <CIT> show examples of cartilage conduction systems.

In this example, to ensure that the interface is able to effectively and/or efficiently transfer the mechanical energy from the transducer to the user's outer ear, the interface may need to have a certain level of stiffness and/or damping and/or hardness (also known as mechanical impedance). Inappropriate selection of this stiffness and/or hardness of the interface may cause the user pain and/or discomfort when wearing the cartilage conduction system. As a result, the user may be dissuaded and/or discouraged from utilizing the cartilage conduction system for long periods of time.

One tradeoff of using a softer and/or more conformable material as the interface may be a decrease in the effectiveness and/or efficiency of the interface's energy transfer capabilities. For example, while a softer and/or more conformable interface between the transducer and the user's outer ear may support better user comfort, this softer and/or more conformable interface may be unable to effectively and/or efficiently transfer the mechanical energy from the transducer to the user's outer ear. As a result, the softer and/or more conformable interface may impair and/or harm the cartilage conduction system's audio performance.

The instant disclosure, therefore, identifies and addresses a need for systems and methods for improving cartilage conduction technology via FGMs.

In one aspect the present invention refers to a cartilage conduction system according to claim <NUM>.

In some embodiments, the gradation of the characteristic exhibited by the FGM interface may comprise a specific gradient of the characteristic from the one side to the another side along one dimension of the FGM interface.

In some embodiments, the characteristic may comprise at least one of: stiffness; loss factor; density; lattice spacing; porosity; Poisson's ratio; or filler content. In some embodiments: the one side of the FGM interface is coupled to the transducer; the another side of the FGM interface is dimensioned to be coupled to the cartilage located on the outer ear of the user; the one side of the FGM interface has a first stiffness modulus; and the another side of the FGM interface has a second stiffness modulus that is lower than the first stiffness modulus. In some embodiments, the another side of the FGM interface contours to the cartilage located on the outer ear of the user.

In some embodiments, the FGM interface is dimensioned to be coupled between the transducer and at least one of: a portion of a helix of the user; a tragus of the user; an antihelix of the user; a scapha of the user; a scaphoid fossa of the user; or a concha of the user. In some embodiments, the transducer generates vibrations that: are transferred to the cartilage located on the outer ear of the user via the FGM interface; and cause the cartilage to generate sound pressure that propagates to an eardrum of the user.

In some embodiments, the FGM interface is anisotropic such that: the FGM interface exhibits a first level of transmissibility in a direction from the transducer to the cartilage; and the FGM interface exhibits a second level of transmissibility in an opposite direction from the cartilage to the transducer, the second level of transmissibility being lower than the first level of transmissibility.

In some embodiments: the mechanical energy comprises vibrations; the cartilage generates sound pressure from the vibrations; and the FGM interface prevents at least some of the vibrations from returning to the transducer in the opposite direction due at least in part to the second level of transmissibility being lower than the first level of transmissibility.

In some embodiments, the cartilage conduction system may further comprise an FGM suppressor that at least partially encompasses a portion of the transducer coupled to the FGM interface, wherein the FGM suppressor: exhibits an additional gradation of at least one characteristic from one side of the FGM suppressor to another side of the FGM suppressor; and mitigates leakage of the mechanical energy generated by the transducer to an environment of the user.

In some embodiments, the gradation of the characteristic exhibited by the FGM interface and the additional gradation of the characteristic exhibited by the FGM suppressor differ from one another.

In some embodiments, the additional gradation of the characteristic exhibited by the FGM suppressor comprises a specific gradient of loss factor from the one side of the FGM suppressor to the another side of the FGM suppressor along one dimension.

In another aspect the present invention refers to an artificial reality system comprising a head mounted display and a cartilage conduction device communicatively coupled to the head-mounted display, wherein the cartilage conduction device comprises a cartilage conduction system as according to claim <NUM>.

Thus, the present invention refers to an artificial reality system comprising: a head-mounted display; and a cartilage conduction system as according to claim <NUM>.

In some embodiments, the FGM interface comprises a plurality of discrete material layers that form the gradation of the characteristic exhibited by the FGM interface.

In some embodiments, the gradation of the characteristic exhibited by the FGM interface comprises a specific gradient of the characteristic from the one side to the another side along one dimension of the FGM interface.

In some embodiments, the characteristic comprises at least one of: stiffness; loss factor; density; lattice spacing; porosity; Poisson's ratio; or filler content.

In another aspect the present invention refers to a method as according to claim <NUM>.

The accompanying Drawings illustrate a number of exemplary embodiments and are parts of the specification. Together with the following description, the Drawings demonstrate and explain various principles of the instant disclosure.

The matter for which protection is sought is uniquely defined by the matter of independent claims <NUM>, <NUM>.

The present disclosure is generally directed to systems and methods for improving cartilage conduction technology via functionally graded materials (FGMs). As will be explained in greater detail below, these systems and methods may provide numerous features and benefits.

In some examples, cartilage conduction technology may involve exciting auricular cartilage located on an outer ear (sometimes referred to as the pinna) of a user. In such examples, the excitation of the cartilage may cause the cartilage to generate sound pressure that propagates through the user's ear canal toward the user's eardrum. Unfortunately, some cartilage conduction technologies may have certain drawbacks and/or design tradeoffs that give rise to one or more deficiencies. In other words, such cartilage conduction technologies may fail to provide a solution that addresses certain competing goals and/or objectives (e.g., high audio performance versus high user comfort).

For example, a cartilage conduction system may include a transducer that generates mechanical energy and an interface that couples the transducer to the outer ear of a user. In this example, to ensure that the interface is able to effectively and/or efficiently transfer the mechanical energy from the transducer to the user's outer ear, the interface may need to have a certain level of stiffness and/or damping and/or hardness (also known as mechanical impedance). Inappropriate selection of this stiffness and/or hardness of the interface may cause the user pain and/or discomfort when wearing the cartilage conduction system. As a result, the user may be dissuaded and/or discouraged from utilizing the cartilage conduction system for long periods of time.

The instant disclosure, therefore, identifies and addresses a need for systems and methods for improving cartilage conduction technology via FGMs. For example, as will be described in greater detail below, the various systems and methods disclosed herein may include and/or incorporate an FGM interface for coupling a transducer to cartilage located on the outer ear of a user. In this example, the FGM interface may exhibit a gradation of at least one characteristic (such as stiffness, hardness, loss factor or damping, density, lattice spacing, porosity, layer geometry and thickness, Poisson's ratio, and/or filler content) from one side to another. In other words, the gradation of the characteristic may constitute and/or represent a specific gradient of the characteristic across the FGM interface along one dimension and/or direction. By including and/or incorporating an FGM interface in this way, these systems and methods may be able to provide a cartilage conduction solution that achieves both high audio performance and high user comfort.

The following will provide, with reference to <FIG>, detailed descriptions of various systems, components, and/or implementations capable of improving cartilage conduction technology via FGMs. The discussion corresponding to <FIG> will provide detailed descriptions of an exemplary method for improving cartilage conduction technology via FGMs. The discussion corresponding to <FIG> will provide detailed descriptions of types of exemplary artificial reality devices and/or systems that may facilitate and/or contribute to users' artificial reality experiences.

<FIG> illustrates an exemplary system <NUM> that improves cartilage conduction technology via FGMs. In some examples, system <NUM> may include and/or represent a cartilage conduction device, system, and/or technology. In one example, system <NUM> may be incorporated into and/or represent part of a wearable device. The terms "wearable" and "wearable device" may refer to any type or form of computing device that is worn by a user of an artificial reality system and/or visual display system as part of an article of clothing, an accessory, and/or an implant. Examples of wearable devices include, without limitation, headsets, headbands, head-mounted displays, glasses, frames, variations or combinations of one or more of the same, and/or any other suitable wearable devices.

As illustrated in <FIG>, exemplary system <NUM> may include a transducer <NUM> that generates mechanical energy <NUM>. In some examples, mechanical energy <NUM> generated by transducer <NUM> may include and/or represent vibrations, acoustic waves, and/or sound pressure. In one example, mechanical energy <NUM> may constitute and/or represent audio information and/or signals capable of being comprehended and/or discerned by a user of system <NUM>. Additionally or alternatively, mechanical energy <NUM> may be converted, transformed, and/or modified by cartilage located on the user's outer ear to sound pressure capable of being comprehended and/or discerned by the user. Examples of transducer <NUM> include, without limitation, tactile transducers, loudspeakers, voice coil speakers, ribbon speakers, electrostatic speakers, piezoelectric transducers, electroacoustic transducers, cartilage conduction transducers, actuators, combinations or variations of one or more of the same, and/or any other suitable transducer.

Transducer <NUM> may have any suitable shape and/or size. In some examples, transducer <NUM> may be scaled to fit comfortably on and/or at the user's outer ear. In one example, transducer <NUM> may be smallerthan a centimeter in length or diameter. Additionally or alternatively, transducer <NUM> may be smaller than <NUM> millimeters in length or diameter.

As illustrated in <FIG>, exemplary system <NUM> may also include an FGM interface <NUM> dimensioned to be coupled between transducer <NUM> and cartilage located on the user's outer ear. In some examples, FGM interface <NUM> may be coupled to transducer <NUM> by any type or form of attachment mechanism. Additionally or alternatively, FGM interface <NUM> may be coupled to the user's outer ear by any type or form of attachment mechanism. Examples of such attachment mechanisms include, without limitation, adhesives (e.g., glues and/or silicones), sticky surfaces, fasteners, press-fit fastenings, interference-fit fastenings, friction-fit fastenings, slip-fit fastenings, magnetic fasteners, locks, pins, screws, joints, ties, clamps, clasps, stitching, staples, zippers, variations or combinations of one or more of the same, and/or any other suitable attachment mechanisms.

In some examples, FGM interface <NUM> may include and/or incorporate one or more FGMs. In one example, FGM interface <NUM> may exhibit a gradation <NUM> of at least one characteristic, attribute, quality, and/or property from one side and/or end of FGM interface <NUM> to another. In this example, FGM interface <NUM> may facilitate transferring mechanical energy <NUM> generated by transducer <NUM> across gradation <NUM> to the cartilage located on the user's outer ear. Examples of graded characteristics of FGM interface <NUM> include, without limitation, stiffness, hardness, modulus (e.g., Young's modulus), loss factor, density, lattice spacing, porosity, Poisson's ratio, filler content, variations or combinations of one or more of the same, and/or any other suitable characteristics.

In some examples, FGM interface <NUM> may include and/or incorporate multiple discrete material layers that collectively form, demonstrate, and/or manifest gradation <NUM> of the characteristic. Additionally or alternatively, FGM interface <NUM> may constitute and/or represent a specific continuous gradient (e.g., a linear gradient) of the characteristic from one side and/or end of FGM interface <NUM> to another. In one example, the specific continuous gradient of the characteristic may run, span, and/or extend along one dimension and/or in one direction of FGM interface <NUM>. Alternatively, the different gradients of one or more characteristics may run, span, and/or extend along different dimensions and/or directions of FGM interface <NUM>.

In some examples, FGM interface <NUM> may include and/or incorporate a variety of different materials. In one example, FGM interface <NUM> may include and/or incorporate one or more meta-materials that are man-made and/or engineered to exhibit certain characteristics that do not exist naturally. Additional examples of materials incorporated in FGM interface <NUM> include, without limitation, foams, polymers, composites, rubbers, papers, plastics, silicones, metals, corks, neoprenes, fiberglasses, polytetrafluorethylenes, elastomer gels, combinations or variations of one or more of the same, and/or any other suitable materials. In a certain embodiment, FGM interface <NUM> may include a mixture of silicone or elastomer gels with a proper mixing ratio. In this embodiment, the shore durometer of the silicone or elastomer mixture may be varied to create a material and/or structure with different stiffness, hardness, and/or damping characteristics.

In some examples, FGM interface <NUM> may include and/or have one side or end that is dimensioned for coupling to transducer <NUM>. In such examples, FGM interface <NUM> may include and/or have another side or end that is dimensioned for coupling to cartilage located on the user's outer ear. In one example, the one side or end dimensioned for coupling to transducer <NUM> may exhibit and/or have a stiffness modulus that is above a certain minimum threshold and/or limit. In this example, the other side or end dimensioned for coupling to the user's outer ear may exhibit and/or have a stiffness modulus that is below a certain maximum threshold and/or limit. Accordingly, the side or end dimensioned for coupling to transducer <NUM> may be harder and/or stiffer than the side or end dimensioned for coupling to the user's outer ear. Put differently, the side or end dimensioned for coupling to the user's outer ear may be softer and/or more conformable than the side or end dimensioned for coupling to transducer <NUM>.

In some examples, the side or end dimensioned for coupling to the user's outer ear may be malleable, flexible, moldable, and/or conformable to the shape of the user's outer ear. For example, the side or end dimensioned for coupling to the user's outer ear may contour to the cartilage located on the user's outer ear, thereby providing the user with a high level of comfort while wearing system <NUM>. As a result, system <NUM> may constitute and/or represent a cartilage conduction solution and/or technology that achieves both high audio performance and high user comfort.

In some examples, FGM interface <NUM> may be manufactured, machined, and/or created in a variety of ways and/or contexts. For example, FGM interface <NUM> may be 3D-printed. Additionally or alternatively, FGM interface <NUM> may be assembled from a set of discrete material layers that are coupled together by any type or form of attachment mechanism, including any of those described above.

In some examples, FGM interface <NUM> may have and/or be formed into any suitable shape and/or size. Examples of such shapes include, without limitation, disks, cubes, cylinders, cuboids, spheres, variations or combinations of one or more of the same, and/or any other suitable shapes.

<FIG> illustrates an exemplary implementation <NUM> of system <NUM> coupled and/or attached to an outer ear <NUM> of a user. In some examples, system <NUM> may be coupled and/or attached to any portion of outer ear <NUM> of the user, including the user's helix, tragus, antihelix, scapha, scaphoid fossa, concha, etc. As illustrated in <FIG>, outer ear <NUM> of the user may include and/or represent a helix <NUM> and/or a tragus <NUM>. In one example, implementation <NUM> may involve and/or represent system <NUM> being coupled and/or attached to tragus <NUM> of the user by FGM interface <NUM>. In this example, transducer <NUM> may generate mechanical energy <NUM> that is transferred and/or carried to cartilage located on tragus <NUM> of the user. Accordingly, on the way from transducer <NUM> to tragus <NUM>, mechanical energy <NUM> may cross, traverse, and/or pass through the characteristic gradation of FGM interface <NUM>.

In one example, as mechanical energy <NUM> arrives at tragus <NUM> via FGM interface <NUM>, the cartilage located on tragus <NUM> may convert and/or transform mechanical energy <NUM> to sound pressure <NUM> that propagates and/or passes through an ear canal <NUM> to the user's eardrum. In this example, sound pressure <NUM> may constitute and/ represent audio information and/or signals intended for listening and/or consumption by the user. Accordingly, the user may be able to listen to the audio information and/or signals represented in sound pressure <NUM>.

<FIG> illustrates an additional exemplary implementation <NUM> of system <NUM> coupled and/or attached to an outer ear <NUM> of a user. As illustrated in <FIG>, implementation <NUM> may involve and/or represent system <NUM> being coupled and/or attached to a helix <NUM> of the user by FGM interface <NUM>. In this example, transducer <NUM> may generate mechanical energy <NUM> that is transferred and/or carried to cartilage located on helix <NUM> of the user. Accordingly, on the way from transducer <NUM> to helix <NUM>, mechanical energy <NUM> may cross, traverse, and/or pass through the characteristic gradation of FGM interface <NUM>.

In one example, as mechanical energy <NUM> arrives at helix <NUM> via FGM interface <NUM>, the cartilage located on helix <NUM> may convert and/or transform mechanical energy <NUM> to sound pressure <NUM> that propagates and/or passes through an ear canal <NUM> to the user's eardrum. In this example, sound pressure <NUM> may constitute and/ represent audio information and/or signals intended for listening and/or consumption by the user. Accordingly, the user may be able to listen to the audio information and/or signals represented in sound pressure <NUM>.

<FIG> illustrates an exemplary representation of FGM interface <NUM>. As illustrated in <FIG>, FGM interface <NUM> may include and/or represent a side <NUM> and a side <NUM>. In one example, FGM interface <NUM> may exhibit, demonstrate, and/or manifest gradation <NUM> of at least one characteristic from side <NUM> to side <NUM>. At side <NUM>, FGM interface <NUM> may have a characteristic grading <NUM>. In contrast, at side <NUM>, FGM interface <NUM> may have a characteristic grading <NUM> that differs from characteristic grading <NUM>. Accordingly, gradation <NUM> may include and/or represent a transition and/or transformation of one or more characteristics (such as stiffness, hardness, loss factor, density, lattice spacing, porosity, Poisson's ratio, and/or filler content) from side <NUM> to side <NUM>.

As a specific example, characteristic grading <NUM> may represent a certain level of stiffness modulus at side <NUM> of FGM interface <NUM>. Characteristic grading <NUM> may represent a different level of stiffness modulus at side <NUM> of FGM interface <NUM>. In this example, characteristic grading <NUM> may correspond to a harder and/or stiffer modulus than characteristic grading <NUM>. Put another way, characteristic grading <NUM> may correspond to a softer and/or more conformable modulus than characteristic grading <NUM>. In certain embodiments, gradation <NUM> may continuously vary from side <NUM> to side <NUM>.

<FIG> illustrates an exemplary representation of FGM interface <NUM>. As illustrated in <FIG>, FGM interface <NUM> may include and/or represent a series of discrete material layers <NUM>(<NUM>), <NUM>(<NUM>), <NUM>(<NUM>), and <NUM>(N) (collectively referred to as discrete material layers <NUM>(<NUM>)-(N)). As a whole, discrete material layers <NUM>(<NUM>)-(N) may exhibit and/or form gradation <NUM> of one or more characteristic and/or properties. In one example, the characteristics and/or properties of discreet material layers <NUM>(<NUM>)-(N) may be represented and/or characterized by a gradation graph <NUM> in <FIG>.

As illustrated in <FIG>, gradation graph <NUM> may represent discreet material layer <NUM>(<NUM>) as having a composition and/or structure characterized by "E<NUM>,ή<NUM>". In this example, gradation graph <NUM> may also represent discreet material layer <NUM>(<NUM>) as having a composition and/or structure characterized by "E<NUM>,ή<NUM>". Gradation graph <NUM> may further represent discreet material layer <NUM>(<NUM>) as having a composition and/or structure characterized by "E<NUM>,ή<NUM>". In addition, gradation graph <NUM> may represent discreet material layer <NUM>(<NUM>) as having a composition and/or structure characterized by "E<NUM>,ή<NUM>".

<FIG> illustrates an additional exemplary implementation <NUM> of system <NUM> coupled and/or attached to outer ear <NUM> of a user. As illustrated in <FIG>, FGM interface <NUM> may facilitate mechanically and/or audibly coupling transducer <NUM> to outer ear <NUM> of the user. In one example, transducer <NUM> may be coupled and/or attached to FGM interface <NUM> at side <NUM>. In this example, outer ear <NUM> of the user may be coupled and/or attached to FGM interface <NUM> at side <NUM>.

In some examples, FGM interface <NUM> may be anisotropic and/or unidirectional. In other words, FGM interface <NUM> may support and/or facilitate one-way communication and/or transfer of mechanical energy <NUM>. Accordingly, FGM interface <NUM> may exhibit, demonstrate, and/or manifest one level of transmissibility in a direction <NUM> and another level of transmissibility in a direction <NUM>. For example, FGM interface <NUM> may have high transmissibility in direction <NUM> but much less transmissibility in direction <NUM>. In this example, FGM interface <NUM> may effectively and/or efficiently transfer, carry, and/or transmit mechanical energy <NUM> in direction <NUM> from transducer <NUM> to outer ear <NUM>. However, FGM interface <NUM> may be unable to effectively and/or efficiently transfer, carry, and/or transmit mechanical energy <NUM> in direction <NUM> from outer ear <NUM> to transducer <NUM>. Accordingly, FGM interface <NUM> may prevent at least some of mechanical energy <NUM> from returning to transducer <NUM> in direction <NUM> due at least in part to the transmissibility of direction <NUM> being less or lower than the transmissibility of direction <NUM>.

In some examples, FGM interface <NUM> may efficiently couple mechanical energy <NUM> from transducer <NUM> to outer ear <NUM>. Additionally or alternatively, FGM interface <NUM> may efficiently decouple and/or uncouple mechanical energy <NUM> from returning back to transducer <NUM>. In other words, FGM interface <NUM> may efficiently prevent mechanical energy <NUM> from ricocheting and/or reflecting off outer ear <NUM> back toward transducer <NUM>.

In some examples, FGM interface <NUM> may be impedance-matched at sides <NUM> and <NUM>. For example, side <NUM> of FGM interface <NUM> may be impedance-matched to transducer <NUM>. In this example, side <NUM> of FGM interface <NUM> and transducer <NUM> may have similar and/or identical impedances to one another. Additionally or alternatively, side <NUM> of FGM interface <NUM> and transducer <NUM> may have impedances that facilitate maximizing energy transfer and/or minimizing signal reflection.

In another example, side <NUM> of FGM interface <NUM> may be impedance-matched to outer ear <NUM>. In this example, side <NUM> of FGM interface <NUM> and outer ear <NUM> may have similar and/or identical impedances to one another. Additionally or alternatively, side <NUM> of FGM interface <NUM> and outer ear <NUM> may have impedances that facilitate maximizing energy transfer and/or minimizing signal reflection.

<FIG> illustrates an additional exemplary system <NUM> for improving cartilage conduction technology via FGMs. As illustrated in <FIG>, exemplary system <NUM> may, like system <NUM> in <FIG>, include transducer <NUM> that generates mechanical energy <NUM> and FGM interface <NUM> for coupling between transducer <NUM> and the outer ear of a user. However, unlike system <NUM> in <FIG>, exemplary system <NUM> may also include an FGM suppressor <NUM> that at least partially encompasses a portion of transducer <NUM> coupled to FGM interface <NUM>. In one example, FGM suppressor <NUM> and FGM interface <NUM> may represent, constitute, and/or form a single conjoined FGM unit. Alternatively, FGM suppressor <NUM> and FGM interface <NUM> may represent and/or constitute distinct or discrete FGM units that abut one another.

In some examples, FGM suppressor <NUM> and FGM interface <NUM> may share one or more characteristics in common, including any of those described above. Like FGM interface <NUM>, FGM suppressor <NUM> may exhibit, demonstrate, and/or manifest a gradation <NUM> of one or more characteristics from one side to another. However, in one example, gradation <NUM> exhibited by FGM suppressor <NUM> and gradation <NUM> exhibited by FGM interface <NUM> may differ from one another. For example, relative to exemplary system <NUM> in <FIG>, gradation <NUM> exhibited by FGM interface <NUM> may run, span, and/or extend along one dimension or direction (e.g., along the y-axis in <FIG>), whereas gradation <NUM> exhibited by FGM suppressor <NUM> may run, span, and/or extend along another dimension or direction (e.g., along the x-axis in <FIG>). Additionally or alternatively, FGM suppressor <NUM> and FGM interface <NUM> may have differing characteristic and/or property gradings relative to one another.

In some examples, FGM suppressor <NUM> may mitigate and/or reduce leakage of mechanical energy <NUM> generated by transducer <NUM> to the user's environment and/or the surrounding air. In doing so, FGM suppressor <NUM> may increase user privacy by containing and/or suppressing mechanical energy <NUM> to the user's personal space. In one example, gradation <NUM> exhibited by FGM suppressor <NUM> and/or gradation <NUM> exhibited by FGM interface <NUM> may be designed and/or oriented to improve and/or maximize such privacy.

In one example, gradation <NUM> exhibited by FGM suppressor <NUM> may constitute and/or represent a specific gradient (e.g., a linear gradient) of loss factor from one side and/or end of FGM suppressor <NUM> to another. In this example, the specific gradient of loss factor may run, span, and/or extend along one dimension and/or in one direction (e.g., along the x-axis in <FIG>) of FGM suppressor <NUM>.

In some examples, FGM suppressor <NUM> may have and/or be formed into any suitable shape and/or size. Examples of such shapes include, without limitation, disks, cubes, cylinders, cuboids, spheres, variations or combinations of one or more of the same, and/or any other suitable shapes.

<FIG> is a flow diagram of an exemplary method <NUM> for improving cartilage conduction technology via FGMs. In one example, the steps shown in <FIG> may be performed as part of assembling and/or manufacturing a cartilage conduction system. Additionally or alternatively, the steps shown in <FIG> may also incorporate and/or involve various sub-steps and/or variations consistent with the descriptions provided above in connection with <FIG>.

As illustrated in <FIG>, method <NUM> may include a step <NUM> in which an FGM interface is manufactured. In one example, a computing equipment manufacturer or subcontractor may create, construct, and/or fabricate the FGM interface. For example, the computing equipment manufacturer or subcontractor may 3D-print the FGM interface. In this example, the FGM interface may exhibit a gradation of one or more characteristics from one side to another. Additionally or alternatively, the FGM interface may be dimensioned for coupling to cartilage located on an outer ear of a user.

As illustrated in <FIG>, method <NUM> may include a step <NUM> in which the FGM interface is coupled to a transducer that generates mechanical energy. In one example, the computing equipment manufacturer or subcontractor may couple, attach, and/or adhere the FGM interface to the transducer. For example, the computing equipment manufacturer or subcontractor may couple the FGM interface to the transducer with an adhesive (such as silicone). In some examples, this coupling between the FGM interface and the transducer may enable the FGM interface to transfer and/or carry the mechanical energy across the gradation of the characteristic(s) from the transducer to the cartilage located on the user's outer ear.

As described above in connection with <FIG>, a cartilage conduction system may include a transducer that generates vibrations and an FGM interface coupled between the transducer and a user's pinna. In some examples, the FGM interface may have a property grading from one side to another. In such examples, the FGM interface may transfer and/or carry the vibrations generated by the transducer across the property grading to the user's pinna. As the vibrations arrive at the user's pinna, cartilage may convert the vibrations to sound pressure that then traverses the user's ear canal toward his or her ear drum for consumption and/or listening.

In some examples, the FGM interface may couple the vibrations to the user's pinna and/or decouple the vibrations that arrive at the user's pinna from the transducer. In such examples, the FGM interface may avoid unnecessarily attenuating the vibrations passing from the transducer to the user's pinna. Accordingly, the FGM interface may facilitate unidirectional delivery of the vibrations generated by the transducer.

In some examples, the FGM interface may include and/or represent a series of composite materials whose microstructures vary from one to the next. This variation of microstructures may effectively tune the properties of the FGM interface to satisfy traditionally competing requirements (e.g., high audio performance and high user comfort) of the cartilage conduction system.

The FGM interface may take a variety of different forms. For example, the FGM interface may include and/or represent standard FGMs with regular geometries that feature property gradation along a single dimension and/or direction. Alternatively, the FGM interface may include and/or represent irregular FGMs with complex geometries that feature different property gradations along different dimensions and/or directions. These irregular FGMs may support and/or facilitate unidirectional coupling of vibrations from the transducer to the user's pinna. Additionally or alternatively, these irregular FGMs may minimize the leakage of sound and/or noise to the user's environment, thereby improving and/or increasing the user's privacy. One way of minimizing such leakage may be to incrementally grade the loss factor of the side walls (e.g., FGM suppressor <NUM> in <FIG>) to make them more lossy. These lossy side walls may effectively minimize the transmissibility of vibrations to the user's environment. Finally, the FGM interface may include and/or incorporate certain man-made and/or engineered meta-materials that do not occur in nature.

The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. The embodiments disclosed herein should be considered in all respects illustrative and not restrictive.

Embodiments of the present disclosure may include or be implemented in conjunction with various types of artificial reality systems. Artificial reality is a form of reality that has been adjusted in some manner before presentation to a user, which may include, e.g., a virtual reality, an augmented reality, a mixed reality, a hybrid reality, or some combination and/or derivative thereof. Artificial reality content may include completely generated content or generated content combined with captured (e.g., real-world) content. The artificial reality content may include video, audio, haptic feedback, or some combination thereof, any of which may be presented in a single channel or in multiple channels (such as stereo video that produces a three-dimensional (3D) effect to the viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof, that are used to, e.g., create content in an artificial reality and/or are otherwise used in (e.g., to perform activities in) an artificial reality.

Artificial reality systems may be implemented in a variety of different form factors and configurations. Some artificial reality systems may be designed to work without near-eye displays (NEDs), an example of which is augmented reality system <NUM> in <FIG>. Other artificial reality systems may include an NED that also provides visibility into the real world (e.g., augmented reality system <NUM> in <FIG>) or that visually immerses a user in an artificial reality (e.g., virtual reality system <NUM> in <FIG>). While some artificial reality devices may be self-contained systems, other artificial reality devices may communicate and/or coordinate with external devices to provide an artificial reality experience to a user. Examples of such external devices include handheld controllers, mobile devices, desktop computers, devices worn by a user, devices worn by one or more other users, and/or any other suitable external system.

Turning to <FIG>, augmented reality system <NUM> generally represents a wearable device dimensioned to fit about a body part (e.g., a head) of a user. As shown in <FIG>, system <NUM> may include a frame <NUM> and a camera assembly <NUM> that is coupled to frame <NUM> and configured to gather information about a local environment by observing the local environment. Augmented reality system <NUM> may also include one or more audio devices, such as output audio transducers <NUM>(A) and <NUM>(B) and input audio transducers <NUM>. Output audio transducers <NUM>(A) and <NUM>(B) may provide audio feedback and/or content to a user, and input audio transducers <NUM> may capture audio in a user's environment.

As shown, augmented reality system <NUM> may not necessarily include an NED positioned in front of a user's eyes. Augmented reality systems without NEDs may take a variety of forms, such as head bands, hats, hair bands, belts, watches, wrist bands, ankle bands, rings, neckbands, necklaces, chest bands, eyewear frames, and/or any other suitable type or form of apparatus. While augmented reality system <NUM> may not include an NED, augmented reality system <NUM> may include other types of screens or visual feedback devices (e.g., a display screen integrated into a side of frame <NUM>).

The embodiments discussed in this disclosure may also be implemented in augmented reality systems that include one or more NEDs. For example, as shown in <FIG>, augmented reality system <NUM> may include an eyewear device <NUM> with a frame <NUM> configured to hold a left display device <NUM>(A) and a right display device <NUM>(B) in front of a user's eyes. Display devices <NUM>(A) and <NUM>(B) may act together or independently to present an image or series of images to a user. While augmented reality system <NUM> includes two displays, embodiments of this disclosure may be implemented in augmented reality systems with a single NED or more than two NEDs.

In some embodiments, augmented reality system <NUM> may include one or more sensors, such as sensor <NUM>. Sensor <NUM> may generate measurement signals in response to motion of augmented reality system <NUM> and may be located on substantially any portion of frame <NUM>. Sensor <NUM> may represent a position sensor, an inertial measurement unit (IMU), a depth camera assembly, or any combination thereof. In some embodiments, augmented reality system <NUM> may or may not include sensor <NUM> or may include more than one sensor. In embodiments in which sensor <NUM> includes an IMU, the IMU may generate calibration data based on measurement signals from sensor <NUM>. Examples of sensor <NUM> may include, without limitation, accelerometers, gyroscopes, magnetometers, other suitable types of sensors that detect motion, sensors used for error correction of the IMU, or some combination thereof.

Augmented reality system <NUM> may also include a microphone array with a plurality of acoustic transducers <NUM>(A)- <NUM>(J), referred to collectively as acoustic transducers <NUM>. Acoustic transducers <NUM> may be transducers that detect air pressure variations induced by sound waves. Each acoustic transducer <NUM> may be configured to detect sound and convert the detected sound into an electronic format (e.g., an analog or digital format). The microphone array in <FIG> may include, for example, ten acoustic transducers: <NUM>(A) and <NUM>(B), which may be designed to be placed inside a corresponding ear of the user, acoustic transducers <NUM>(C), <NUM>(D), <NUM>(E), <NUM>(F), <NUM>(G), and <NUM>(H), which may be positioned at various locations on frame <NUM>, and/or acoustic transducers <NUM>(I) and <NUM>(J), which may be positioned on a corresponding neckband <NUM>.

In some embodiments, one or more of acoustic transducers <NUM>(A)-(F) may be used as output transducers (e.g., speakers). For example, acoustic transducers <NUM>(A) and/or <NUM>(B) may be earbuds or any other suitable type of headphone or speaker.

The configuration of acoustic transducers <NUM> of the microphone array may vary. While augmented reality system <NUM> is shown in <FIG> as having ten acoustic transducers <NUM>, the number of acoustic transducers <NUM> may be greater or less than ten. In some embodiments, using higher numbers of acoustic transducers <NUM> may increase the amount of audio information collected and/or the sensitivity and accuracy of the audio information. In contrast, using a lower number of acoustic transducers <NUM> may decrease the computing power required by an associated controller <NUM> to process the collected audio information. In addition, the position of each acoustic transducer <NUM> of the microphone array may vary. For example, the position of an acoustic transducer <NUM> may include a defined position on the user, a defined coordinate on frame <NUM>, an orientation associated with each acoustic transducer <NUM>, or some combination thereof.

Acoustic transducers <NUM>(A) and <NUM>(B) may be positioned on different parts of the user's ear, such as behind the pinna or within the auricle or fossa. Or, there may be additional acoustic transducers <NUM> on or surrounding the ear in addition to acoustic transducers <NUM> inside the ear canal. Having an acoustic transducer <NUM> positioned next to an ear canal of a user may enable the microphone array to collect information on how sounds arrive at the ear canal. By positioning at least two of acoustic transducers <NUM> on either side of a user's head (e.g., as binaural microphones), augmented reality device <NUM> may simulate binaural hearing and capture a 3D stereo sound field around about a user's head. In some embodiments, acoustic transducers <NUM>(A) and <NUM>(B) may be connected to augmented reality system <NUM> via a wired connection <NUM>, and in other embodiments, acoustic transducers <NUM>(A) and <NUM>(B) may be connected to augmented reality system <NUM> via a wireless connection (e.g., a Bluetooth connection). In still other embodiments, acoustic transducers <NUM>(A) and <NUM>(B) may not be used at all in conjunction with augmented reality system <NUM>.

Acoustic transducers <NUM> on frame <NUM> may be positioned along the length of the temples, across the bridge, above or below display devices <NUM>(A) and <NUM>(B), or some combination thereof. Acoustic transducers <NUM> may be oriented such that the microphone array is able to detect sounds in a wide range of directions surrounding the user wearing the augmented reality system <NUM>. In some embodiments, an optimization process may be performed during manufacturing of augmented reality system <NUM> to determine relative positioning of each acoustic transducer <NUM> in the microphone array.

In some examples, augmented reality system <NUM> may include or be connected to an external device (e.g., a paired device), such as neckband <NUM>. Neckband <NUM> generally represents any type or form of paired device. Thus, the following discussion of neckband <NUM> may also apply to various other paired devices, such as charging cases, smart watches, smart phones, wrist bands, other wearable devices, hand-held controllers, tablet computers, laptop computers and other external compute devices, etc..

As shown, neckband <NUM> may be coupled to eyewear device <NUM> via one or more connectors. The connectors may be wired or wireless and may include electrical and/or non-electrical (e.g., structural) components. In some cases, eyewear device <NUM> and neckband <NUM> may operate independently without any wired or wireless connection between them. While <FIG> illustrates the components of eyewear device <NUM> and neckband <NUM> in example locations on eyewear device <NUM> and neckband <NUM>, the components may be located elsewhere and/or distributed differently on eyewear device <NUM> and/or neckband <NUM>. In some embodiments, the components of eyewear device <NUM> and neckband <NUM> may be located on one or more additional peripheral devices paired with eyewear device <NUM>, neckband <NUM>, or some combination thereof.

Pairing external devices, such as neckband <NUM>, with augmented reality eyewear devices may enable the eyewear devices to achieve the form factor of a pair of glasses while still providing sufficient battery and computation power for expanded capabilities. Some or all of the battery power, computational resources, and/or additional features of augmented reality system <NUM> may be provided by a paired device or shared between a paired device and an eyewear device, thus reducing the weight, heat profile, and form factor of the eyewear device overall while still retaining desired functionality. For example, neckband <NUM> may allow components that would otherwise be included on an eyewear device to be included in neckband <NUM> since users may tolerate a heavier weight load on their shoulders than they would tolerate on their heads. Neckband <NUM> may also have a larger surface area over which to diffuse and disperse heat to the ambient environment. Thus, neckband <NUM> may allow for greater battery and computation capacity than might otherwise have been possible on a stand-alone eyewear device. Since weight carried in neckband <NUM> may be less invasive to a user than weight carried in eyewear device <NUM>, a user may tolerate wearing a lighter eyewear device and carrying or wearing the paired device for greater lengths of time than a user would tolerate wearing a heavy standalone eyewear device, thereby enabling users to more fully incorporate artificial reality environments into their day-to-day activities.

Neckband <NUM> may be communicatively coupled with eyewear device <NUM> and/or to other devices. These other devices may provide certain functions (e.g., tracking, localizing, depth mapping, processing, storage, etc.) to augmented reality system <NUM>. In the embodiment of <FIG>, neckband <NUM> may include two acoustic transducers (e.g., <NUM>(I) and <NUM>(J)) that are part of the microphone array (or potentially form their own microphone subarray). Neckband <NUM> may also include a controller <NUM> and a power source <NUM>.

Acoustic transducers <NUM>(I) and <NUM>(J) of neckband <NUM> may be configured to detect sound and convert the detected sound into an electronic format (analog or digital). In the embodiment of <FIG>, acoustic transducers <NUM>(I) and <NUM>(J) may be positioned on neckband <NUM>, thereby increasing the distance between the neckband acoustic transducers <NUM>(I) and <NUM>(J) and other acoustic transducers <NUM> positioned on eyewear device <NUM>. In some cases, increasing the distance between acoustic transducers <NUM> of the microphone array may improve the accuracy of beamforming performed via the microphone array. For example, if a sound is detected by acoustic transducers <NUM>(C) and <NUM>(D) and the distance between acoustic transducers <NUM>(C) and <NUM>(D) is greater than, e.g., the distance between acoustic transducers <NUM>(D) and <NUM>(E), the determined source location of the detected sound may be more accurate than if the sound had been detected by acoustic transducers <NUM>(D) and <NUM>(E).

Controller <NUM> of neckband <NUM> may process information generated by the sensors on neckband <NUM> and/or augmented reality system <NUM>. For example, controller <NUM> may process information from the microphone array that describes sounds detected by the microphone array. For each detected sound, controller <NUM> may perform a direction-of-arrival (DOA) estimation to estimate a direction from which the detected sound arrived at the microphone array. As the microphone array detects sounds, controller <NUM> may populate an audio data set with the information. In embodiments in which augmented reality system <NUM> includes an inertial measurement unit, controller <NUM> may compute all inertial and spatial calculations from the IMU located on eyewear device <NUM>. A connector may convey information between augmented reality system <NUM> and neckband <NUM> and between augmented reality system <NUM> and controller <NUM>. The information may be in the form of optical data, electrical data, wireless data, or any other transmittable data form. Moving the processing of information generated by augmented reality system <NUM> to neckband <NUM> may reduce weight and heat in eyewear device <NUM>, making it more comfortable to the user.

Power source <NUM> in neckband <NUM> may provide power to eyewear device <NUM> and/or to neckband <NUM>. Power source <NUM> may include, without limitation, lithium ion batteries, lithium-polymer batteries, primary lithium batteries, alkaline batteries, or any other form of power storage. In some cases, power source <NUM> may be a wired power source. Including power source <NUM> on neckband <NUM> instead of on eyewear device <NUM> may help better distribute the weight and heat generated by power source <NUM>.

As noted, some artificial reality systems may, instead of blending an artificial reality with actual reality, substantially replace one or more of a user's sensory perceptions of the real world with a virtual experience. One example of this type of system is a head-worn display system, such as virtual reality system <NUM> in <FIG>, that mostly or completely covers a user's field of view. Virtual reality system <NUM> may include a front rigid body <NUM> and a band <NUM> shaped to fit around a user's head. Virtual reality system <NUM> may also include output audio transducers <NUM>(A) and <NUM>(B). Furthermore, while not shown in <FIG>, front rigid body <NUM> may include one or more electronic elements, including one or more electronic displays, one or more inertial measurement units (IMUs), one or more tracking emitters or detectors, and/or any other suitable device or system for creating an artificial reality experience.

Artificial reality systems may include a variety of types of visual feedback mechanisms. For example, display devices in augmented reality system <NUM> and/or virtual reality system <NUM> may include one or more liquid crystal displays (LCDs), light emitting diode (LED) displays, organic LED (OLED) displays, and/or any other suitable type of display screen. Artificial reality systems may include a single display screen for both eyes or may provide a display screen for each eye, which may allow for additional flexibility for varifocal adjustments or for correcting a user's refractive error. Some artificial reality systems may also include optical subsystems having one or more lenses (e.g., conventional concave or convex lenses, Fresnel lenses, adjustable liquid lenses, etc.) through which a user may view a display screen.

In addition to or instead of using display screens, some artificial reality systems may include one or more projection systems. For example, display devices in augmented reality system <NUM> and/or virtual reality system <NUM> may include micro-LED projectors that project light (using, e.g., a waveguide) into display devices, such as clear combiner lenses that allow ambient light to pass through. The display devices may refract the projected light toward a user's pupil and may enable a user to simultaneously view both artificial reality content and the real world. Artificial reality systems may also be configured with any other suitable type or form of image projection system.

Artificial reality systems may also include various types of computer vision components and subsystems. For example, augmented reality system <NUM>, augmented reality system <NUM>, and/or virtual reality system <NUM> may include one or more optical sensors, such as two-dimensional (2D) or 3D cameras, time-of-flight depth sensors, single-beam or sweeping laser rangefinders, 3D LiDAR sensors, and/or any other suitable type or form of optical sensor. An artificial reality system may process data from one or more of these sensors to identify a location of a user, to map the real world, to provide a user with context about real-world surroundings, and/or to perform a variety of other functions.

Artificial reality systems may also include one or more input and/or output audio transducers. In the examples shown in <FIG> and <FIG>, output audio transducers <NUM>(A), <NUM>(B), <NUM>(A), and <NUM>(B) may include voice coil speakers, ribbon speakers, electrostatic speakers, piezoelectric speakers, bone conduction transducers, cartilage conduction transducers, and/or any other suitable type or form of audio transducer. Similarly, input audio transducers <NUM> may include condenser microphones, dynamic microphones, ribbon microphones, and/or any other type or form of input transducer. In some embodiments, a single transducer may be used for both audio input and audio output.

While not shown in <FIG>, artificial reality systems may include tactile (i.e., haptic) feedback systems, which may be incorporated into headwear, gloves, body suits, handheld controllers, environmental devices (e.g., chairs, floormats, etc.), and/or any other type of device or system. Haptic feedback systems may provide various types of cutaneous feedback, including vibration, force, traction, texture, and/or temperature. Haptic feedback systems may also provide various types of kinesthetic feedback, such as motion and compliance. Haptic feedback may be implemented using motors, piezoelectric actuators, fluidic systems, and/or a variety of other types of feedback mechanisms. Haptic feedback systems may be implemented independent of other artificial reality devices, within other artificial reality devices, and/or in conjunction with other artificial reality devices.

By providing haptic sensations, audible content, and/or visual content, artificial reality systems may create an entire virtual experience or enhance a user's real-world experience in a variety of contexts and environments. For instance, artificial reality systems may assist or extend a user's perception, memory, or cognition within a particular environment. Some systems may enhance a user's interactions with other people in the real world or may enable more immersive interactions with other people in a virtual world. Artificial reality systems may also be used for educational purposes (e.g., for teaching or training in schools, hospitals, government organizations, military organizations, business enterprises, etc.), entertainment purposes (e.g., for playing video games, listening to music, watching video content, etc.), and/or for accessibility purposes (e.g., as hearing aids, visuals aids, etc.). The embodiments disclosed herein may enable or enhance a user's artificial reality experience in one or more of these contexts and environments and/or in other contexts and environments.

As noted, artificial reality systems <NUM>, <NUM>, and <NUM> may be used with a variety of other types of devices to provide a more compelling artificial reality experience. These devices may be haptic interfaces with transducers that provide haptic feedback and/or that collect haptic information about a user's interaction with an environment. The artificial reality systems disclosed herein may include various types of haptic interfaces that detect or convey various types of haptic information, including tactile feedback (e.g., feedback that a user detects via nerves in the skin, which may also be referred to as cutaneous feedback) and/or kinesthetic feedback (e.g., feedback that a user detects via receptors located in muscles, joints, and/or tendons).

Haptic feedback may be provided by interfaces positioned within a user's environment (e.g., chairs, tables, floors, etc.) and/or interfaces on articles that may be worn or carried by a user (e.g., gloves, wristbands, etc.). As an example, <FIG> illustrates a vibrotactile system <NUM> in the form of a wearable glove (haptic device <NUM>) and wristband (haptic device <NUM>). Haptic device <NUM> and haptic device <NUM> are shown as examples of wearable devices that include a flexible, wearable textile material <NUM> that is shaped and configured for positioning against a user's hand and wrist, respectively. This disclosure also includes vibrotactile systems that may be shaped and configured for positioning against other human body parts, such as a finger, an arm, a head, a torso, a foot, or a leg. By way of example and not limitation, vibrotactile systems according to various embodiments of the present disclosure may also be in the form of a glove, a headband, an armband, a sleeve, a head covering, a sock, a shirt, or pants, among other possibilities. In some examples, the term "textile" may include any flexible, wearable material, including woven fabric, non-woven fabric, leather, cloth, a flexible polymer material, composite materials, etc..

One or more vibrotactile devices <NUM> may be positioned at least partially within one or more corresponding pockets formed in textile material <NUM> of vibrotactile system <NUM>. Vibrotactile devices <NUM> may be positioned in locations to provide a vibrating sensation (e.g., haptic feedback) to a user of vibrotactile system <NUM>. For example, vibrotactile devices <NUM> may be positioned to be against the user's finger(s), thumb, or wrist, as shown in <FIG>. Vibrotactile devices <NUM> may, in some examples, be sufficiently flexible to conform to or bend with the user's corresponding body part(s).

A power source <NUM> (e.g., a battery) for applying a voltage to the vibrotactile devices <NUM> for activation thereof may be electrically coupled to vibrotactile devices <NUM>, such as via conductive wiring <NUM>. In some examples, each of vibrotactile devices <NUM> may be independently electrically coupled to power source <NUM> for individual activation. In some embodiments, a processor <NUM> may be operatively coupled to power source <NUM> and configured (e.g., programmed) to control activation of vibrotactile devices <NUM>.

Vibrotactile system <NUM> may be implemented in a variety of ways. In some examples, vibrotactile system <NUM> may be a standalone system with integral subsystems and components for operation independent of other devices and systems. As another example, vibrotactile system <NUM> may be configured for interaction with another device or system <NUM>. For example, vibrotactile system <NUM> may, in some examples, include a communications interface <NUM> for receiving and/or sending signals to the other device or system <NUM>. The other device or system <NUM> may be a mobile device, a gaming console, an artificial reality (e.g., virtual reality, augmented reality, mixed reality) device, a personal computer, a tablet computer, a network device (e.g., a modem, a router, etc.), a handheld controller, etc. Communications interface <NUM> may enable communications between vibrotactile system <NUM> and the other device or system <NUM> via a wireless (e.g., Wi-Fi, Bluetooth, cellular, radio, etc.) link or a wired link. If present, communications interface <NUM> may be in communication with processor <NUM>, such as to provide a signal to processor <NUM> to activate or deactivate one or more of the vibrotactile devices <NUM>.

Vibrotactile system <NUM> may optionally include other subsystems and components, such as touch-sensitive pads <NUM>, pressure sensors, motion sensors, position sensors, lighting elements, and/or user interface elements (e.g., an on/off button, a vibration control element, etc.). During use, vibrotactile devices <NUM> may be configured to be activated for a variety of different reasons, such as in response to the user's interaction with user interface elements, a signal from the motion or position sensors, a signal from the touch-sensitive pads <NUM>, a signal from the pressure sensors, a signal from the other device or system <NUM>, etc..

Although power source <NUM>, processor <NUM>, and communications interface <NUM> are illustrated in <FIG> as being positioned in haptic device <NUM>, the present disclosure is not so limited. For example, one or more of power source <NUM>, processor <NUM>, or communications interface <NUM> may be positioned within haptic device <NUM> or within another wearable textile.

Haptic wearables, such as those shown in and described in connection with <FIG>, may be implemented in a variety of types of artificial reality systems and environments. <FIG> shows an example artificial reality environment <NUM> including one head-mounted virtual reality display and two haptic devices (i.e., gloves), and in other embodiments any number and/or combination of these components and other components may be included in an artificial reality system. For example, in some embodiments there may be multiple head-mounted displays each having an associated haptic device, with each head-mounted display and each haptic device communicating with the same console, portable computing device, or other computing system.

Head-mounted display <NUM> generally represents any type or form of virtual reality system, such as virtual reality system <NUM> in <FIG>. Haptic device <NUM> generally represents any type or form of wearable device, worn by a use of an artificial reality system, that provides haptic feedback to the user to give the user the perception that he or she is physically engaging with a virtual object. In some embodiments, haptic device <NUM> may provide haptic feedback by applying vibration, motion, and/or force to the user. For example, haptic device <NUM> may limit or augment a user's movement. To give a specific example, haptic device <NUM> may limit a user's hand from moving forward so that the user has the perception that his or her hand has come in physical contact with a virtual wall. In this specific example, one or more actuators within the haptic advice may achieve the physical-movement restriction by pumping fluid into an inflatable bladder of the haptic device. In some examples, a user may also use haptic device <NUM> to send action requests to a console. Examples of action requests include, without limitation, requests to start an application and/or end the application and/or requests to perform a particular action within the application.

While haptic interfaces may be used with virtual reality systems, as shown in <FIG>, haptic interfaces may also be used with augmented reality systems, as shown in <FIG> is a perspective view a user <NUM> interacting with an augmented reality system <NUM>. In this example, user <NUM> may wear a pair of augmented reality glasses <NUM> that have one or more displays <NUM> and that are paired with a haptic device <NUM>. Haptic device <NUM> may be a wristband that includes a plurality of band elements <NUM> and a tensioning mechanism <NUM> that connects band elements <NUM> to one another.

One or more of band elements <NUM> may include any type or form of actuator suitable for providing haptic feedback. For example, one or more of band elements <NUM> may be configured to provide one or more of various types of cutaneous feedback, including vibration, force, traction, texture, and/or temperature. To provide such feedback, band elements <NUM> may include one or more of various types of actuators. In one example, each of band elements <NUM> may include a vibrotactor (e.g., a vibrotactile actuator) configured to vibrate in unison or independently to provide one or more of various types of haptic sensations to a user. Alternatively, only a single band element or a subset of band elements may include vibrotactors.

Haptic devices <NUM>, <NUM>, <NUM>, and <NUM> may include any suitable number and/or type of haptic transducer, sensor, and/or feedback mechanism. For example, haptic devices <NUM>, <NUM>, <NUM>, and <NUM> may include one or more mechanical transducers, piezoelectric transducers, and/or fluidic transducers. Haptic devices <NUM>, <NUM>, <NUM>, and <NUM> may also include various combinations of different types and forms of transducers that work together or independently to enhance a user's artificial-reality experience. In one example, each of band elements <NUM> of haptic device <NUM> may include a vibrotactor (e.g., a vibrotactile actuator) configured to vibrate in unison or independently to provide one or more of various types of haptic sensations to a user.

The process parameters and sequence of the steps described and/or illustrated herein are given by way of example only and can be varied as desired. The various exemplary methods described and/or illustrated herein may also omit one or more of the steps described or illustrated herein or include additional steps in addition to those disclosed.

Claim 1:
A cartilage conduction system comprising:
a transducer that generates mechanical energy; and
a functionally graded material, FGM, interface dimensioned to be coupled between the transducer and cartilage located on an outer ear of a user, wherein the FGM interface:
exhibits a gradation of at least one characteristic from one side of the FGM interface to another side of the FGM interface; and
facilitates transferring the mechanical energy across the gradation of the characteristic from the transducer to the cartilage;
characterized in that:
the one side is impedance-matched to the transducer; and
the another side is impedance-matched to the cartilage located on the outer ear of the user.