PATENT DOCUMENT

Publication Number: US-10750268-B2
Application Number: US-201816114148-A
Country: US
Kind Code: B2

Title: Capacitive wireless charging for wireless earbuds

Abstract:
A case for a pair of earbuds including a housing having first and second cavities formed within the housing, the first cavity configured to receive a first earbud in the pair of earbuds and the second cavity configured to receive a second earbud in the pair of earbuds; a lid attached to the housing; a first pair of electrodes positioned within the housing adjacent to the first cavity; a second pair of electrodes positioned within the housing adjacent to the second cavity; and charging circuitry coupled to the first and second pairs of electrodes, the charging circuitry including a high frequency inverter configured to receive a DC power signal and output a high frequency AC signal to each of the first and second pairs of electrodes.

Claims:
What is claimed is: 
     
       1. An earbud comprising:
 a housing including a speaker housing portion having an audio exit and a stem housing extending away from the speaker portion; 
 a speaker disposed in the speaker housing portion and operatively coupled to emit sound through the audio exit; 
 a pair of electrodes, the pair of electrodes including a first electrode formed around a first portion of the stem housing and a second electrode, spaced apart from the first electrode and formed over a second portion of the stem housing; 
 a wireless antenna and circuitry coupled to receive a wireless signal over the antenna; 
 a battery; and 
 charging circuitry coupled between the battery and the pair of electrodes, the charging circuitry configured to charge the battery from power received capactively over the pair of electrodes. 
 
     
     
       2. The earbud set forth in  claim 1  wherein the stem housing comprises an elongated tubular member defining a cavity in which the battery and charging circuitry are housed and the pair of electrodes at least partially surrounds the battery and charging circuitry. 
     
     
       3. The earbud set forth in  claim 2  wherein the elongated tubular member has a constant taper such that a distal end of the tubular member has a smaller cross-section than a portion of the tubular member adjacent to the speaker housing. 
     
     
       4. The earbud set forth in  claim 2 , wherein each of the first and second electrodes is between 0.1 microns to 50 microns thick. 
     
     
       5. The earbud set forth in  claim 4  wherein the housing includes a thin dielectric skin formed within the first and second tubular sections covering the first and second pairs of electrodes. 
     
     
       6. The case for a pair of earbuds set forth in  claim 5 , wherein the dielectric skin is between 5 microns-25 microns thick. 
     
     
       7. The earbud set forth in  claim 1  further comprising a dielectric skin formed over the pair of electrodes. 
     
     
       8. The earbud set forth in  claim 1  further comprising a dielectric skin formed over the pair of electrodes. 
     
     
       9. An earbud comprising:
 a housing including a speaker housing portion having an audio exit and a stem housing extending away from the speaker portion; 
 a speaker disposed in the speaker housing portion and operatively coupled to emit sound through the audio exit; 
 a pair of electrodes, the pair of electrodes including a first electrode formed in the speaker portion of the housing and a second electrode, spaced apart from the first electrode and formed in the speaker portion of the housing; 
 a battery; and 
 charging circuitry coupled between the battery and the pair of electrodes, the charging circuitry configured to charge the battery from power received capactively over the pair of electrodes. 
 
     
     
       10. A portable listening device system comprising:
 (a) an earbud comprising:
 an earbud housing including a speaker housing portion having an audio exit and a stem housing extending away from the speaker portion; 
 a speaker disposed in the speaker housing portion and operatively coupled to emit sound through the audio exit; 
 a pair of electrodes, the pair of electrodes including a first electrode formed around a first portion of the stem housing and a second electrode, spaced apart from the first electrode and formed over a second portion of the stem housing; 
 a wireless antenna and circuitry coupled to receive a wireless signal over the antenna; 
 a battery; and 
 charging circuitry coupled between the battery and the pair of electrodes, the charging circuitry configured to charge the battery from power received capactively over the pair of electrodes; and 
 
 (b) a charging case for the earbud, the charging case comprising: 
 a case housing having a cavity formed within the case housing and configured to receive the earbud; 
 a lid attached to the case housing and operable between a closed position where the lid is aligned over the cavity and an open position where cavity is exposed enabling the earbud to be removed from the housing; 
 a pair of electrodes positioned within the case housing adjacent to the first cavity; and 
 charging circuitry coupled to the pair of electrodes, the charging circuitry including a high frequency inverter coupled to receive a DC power signal and configured to output a high frequency AC signal to the pair of electrodes to charge a battery of the earbud when the earbud is received within the cavity. 
 
     
     
       11. The portable listening device system set forth in  claim 10  wherein:
 the earbud is a first earbud in a pair of earbuds; 
 the system includes a second earbud; 
 the case housing includes first and second cavities formed within the case housing, the first cavity configured to receive the first earbud and the second cavity configured to receive the second earbud; 
 the pair of electrodes positioned within the case housing is a first pair of electrodes positioned within the housing adjacent to the first cavity and the case further comprises a second pair of electrodes positioned within the housing adjacent to the second cavity; and 
 the charging circuitry is coupled to and configured to output a high frequency AC signal to each of the first and second pairs of electrodes. 
 
     
     
       12. A portable listening device system comprising:
 (a) a pair of earbuds including a first earbud and a second earbud, each of the first and second earbuds comprising:
 an earbud housing including a speaker housing portion having an audio exit and a stem housing extending away from the speaker portion; 
 a speaker disposed in the speaker housing portion and operatively coupled to emit sound through the audio exit; 
 a pair of electrodes, the pair of electrodes including a first electrode formed around a first portion of the stem housing and a second electrode, spaced apart from the first electrode and formed over a second portion of the stem housing; 
 a wireless antenna and circuitry coupled to receive a wireless signal over the antenna; 
 a battery; and 
 charging circuitry coupled between the battery and the pair of electrodes, the charging circuitry configured to charge the battery from power received capactively over the pair of electrodes; and 
 
 (b) a charging case for the pair of earbuds, the charging case comprising: 
 a case housing having first and second cavities formed within the case housing, the first cavity configured to receive the first earbud in the pair of earbuds and the second cavity configured to receive the second earbud in the pair of earbuds; 
 a lid attached to the case housing and operable between a closed position where the lid is aligned over the first and second cavities and an open position where first and second cavities are exposed enabling the pair of earbuds to be removed from the housing; 
 a first pair of electrodes positioned within the case housing adjacent to the first cavity; 
 a second pair of electrodes positioned within the case housing adjacent to the second cavity; and 
 charging circuitry coupled to the first and second pairs of electrodes, the charging circuitry including a high frequency inverter configured to receive a DC power signal and output a high frequency AC signal to each of the first and second pairs of electrodes. 
 
     
     
       13. The portable listening device system set forth in  claim 12  wherein:
 the first cavity includes a first tubular section defined by an interior surface of the case housing and the second cavity includes a second tubular section defined by an interior surface of the case housing; 
 the first pair of electrodes includes a first electrode surrounding a first portion of the first tubular section and a second electrode, spaced apart from the first electrode and surrounding a second portion of the first tubular section; and 
 the second pair of electrodes includes a third electrode surrounding a first portion of the second tubular section and a fourth electrode, spaced apart from the third electrode and surrounding a second portion of the second tubular section. 
 
     
     
       14. The portable listening device system set forth in  claim 13  wherein each of the first and second cavities includes a constant taper such that an upper portion of each cavity has a larger cross-sectional opening than a bottom portion of each cavity. 
     
     
       15. The portable listening device system set forth in  claim 13  wherein the first and second tubular sections each have a circular cross-section and the first, second, third, and fourth electrodes each have a circular cross-section. 
     
     
       16. The portable listening device system set forth in  claim 13  wherein the first and second tubular sections each have a non-circular cross-section and the first and second electrodes and the third and fourth electrodes each have a substantially similar cross-sectional shape that is slightly larger than that of the first and second tubular sections, respectively. 
     
     
       17. The portable listening device system set forth in  claim 13  wherein the high frequency inverter is configured to generate an AC signal between 2 MHz-50 MHz. 
     
     
       18. The portable listening device system set forth in  claim 13  wherein each of the first, second, third and fourth electrodes is between 0.1 microns to 50 microns thick. 
     
     
       19. The portable listening device system set forth in  claim 18  wherein the case housing includes a thin dielectric skin formed within the first and second tubular sections covering the first and second pairs of electrodes. 
     
     
       20. The portable listening device system set forth in  claim 19  wherein the dielectric skin is between 5 microns-25 microns thick. 
     
     
       21. A portable listening device system comprising:
 (a) a pair of earbuds including a first earbud and a second earbud, each of the first and second earbuds comprising:
 a housing including a speaker housing portion having an audio exit and a stem housing extending away from the speaker portion; 
 a speaker disposed in the speaker housing portion and operatively coupled to emit sound through the audio exit; 
 a pair of electrodes, the pair of electrodes including a first electrode formed in the speaker portion of the housing and a second electrode, spaced apart from the first electrode and formed in the speaker portion of the housing; 
 a battery; and 
 charging circuitry coupled between the battery and the pair of electrodes, the charging circuitry configured to charge the battery from power received capactively over the pair of electrodes; and 
 
 (b) a charging case case for the pair of earbuds, the charging case comprising: 
 a case housing having first and second cavities formed within the case housing, the first cavity configured to receive the first earbud and the second cavity configured to receive the second earbud; 
 a lid attached to the case housing and operable between a closed position where the lid is aligned over the first and second cavities and an open position where first and second cavities are exposed enabling the pair of earbuds to be removed from the case housing, the lid including an electrically conductive and compliant region facing the first and second cavities when the lid is in the closed position; and 
 charging circuitry coupled to the electrically conductive and compliant region, the charging circuitry including a high frequency inverter configured to receive a DC power signal and output a high frequency AC signal to each of the first and second pairs of electrodes. 
 
     
     
       22. The portable listening device system set forth in  claim 21  wherein the electrically conductive and compliant region of the charging case lid extends within the lid across a region that covers both the first and second cavities and comprises a material that has anisotropic conductivity. 
     
     
       23. The portable listening device system set forth in  claim 21  wherein the electrically conductive and compliant region of the charging case lid includes a plurality of electrically isolated regions, the plurality of electrically isolated regions including a first pair of electrically conductive and compliant regions spaced apart from the first cavity and a second pair of electrically conductive and compliant regions spaced apart from the second cavity. 
     
     
       24. The portable listening device system set forth in  claim 21  wherein the first cavity includes a first tubular section configured to accept a stem section of the first earbud and the second cavity includes a second tubular section configured to accept a stem section of the second earbud.

Description:
BACKGROUND OF THE INVENTION 
     The described embodiments relate generally to portable listening devices such as earbuds and other types of in-ear listening devices, and to cases for storing and charging such devices. 
     Portable listening devices can be used with a wide variety of electronic devices such as portable media players, smart phones, tablet computers, laptop computers and stereo systems among others. Portable listening devices have historically included one or more small speakers configured to be place on, in, or near a user&#39;s ear, structural components that hold the speakers in place, and a cable that electrically connects the portable listening device to an audio source. Other portable listening devices can be wireless devices that do not include a cable and instead, wirelessly receive a stream of audio data from a wireless audio source. 
     While wireless portable listening devices have many advantages over wired devices, they also have some potential drawbacks. For example, wireless portable listening devices, typically require a battery, such as a rechargeable battery, that provides power to the wireless communication circuitry and other components of the device. For many currently available wireless portable listening devices, charge can be restored to the rechargeable battery in the device by physically connecting the portable listening device to a power source, which typically requires that the wireless portable listening device have a pair of electrical contacts to receive the charge. 
     In many devices such electrical contacts are positioned within a receptacle connector in the wireless portable listening device. The receptacle connector typically includes a cavity in the wireless portable listening device that provides an avenue within which dust and moisture can intrude and damage the device. Furthermore, a user of the electronic device has to physically connect the charging cable to the receptacle in order to charge the battery. Some other wireless portable listening devices including charging contacts at an external surface of the device, which is a significant improvement with respect to moisture resistance and other potential problems as compared to internal contacts positioned within a receptacle connector cavity. Even external contacts, however, can still result in potential paths for moisture ingression under extreme conditions (for example, at the seams between the contacts and housing) and/or potential corrosion of the contacts when repeatedly exposed to corrosive liquids, such as sweat. 
     BRIEF SUMMARY OF THE INVENTION 
     Some embodiments of the present disclosure pertain to a case that can store and wirelessly charge an in-ear listening device, such as a pair of earbuds. The case can include one or more cavities to hold the in-ear listening device and charging circuitry to provide power to a rechargeable battery within the listening device (or within each of the pair of earbuds). 
     Other embodiments pertain to a pair of earbuds or other type of in-ear listening device that can be wirelessly charged by a case according to the present disclosure. 
     In some embodiments, a case for a portable listening device, such as a pair of earbuds is provided. The case can include a housing having first and second cavities formed within the housing along with a first pair of electrodes positioned within the housing adjacent to the first cavity and a second pair of electrodes positioned within the housing adjacent to the second cavity. The first cavity is configured to receive a first earbud in the pair of earbuds and the second cavity is configured to receive a second earbud in the pair of earbuds. A lid can be attached to the housing and the case includes charging circuitry coupled to the first and second pairs of electrodes that includes a high frequency inverter configured to receive a DC power signal and output a high frequency AC signal to each of the first and second pairs of electrodes enabling the case to charge the pair of earbuds. 
     In some embodiments an earbud is provided that includes a housing including a speaker housing portion having an audio exit and a stem housing extending away from the speaker portion; a speaker disposed in the speaker housing portion and operatively coupled to emit sound through the audio exit; a pair of electrodes, including a first electrode formed around a first portion of the stem housing and a second electrode, spaced apart from the first electrode and formed over a second portion of the stem housing; a wireless antenna and circuitry coupled to receive a wireless signal over the antenna; a battery; and charging circuitry coupled between the battery and the pair of electrodes where the charging circuitry is configured to charge the battery from capacitive power received over the pair of electrodes. 
     Some embodiments pertain to a case for a pair of earbuds that includes a conformable electrode in the lid of the case. The case can include a housing having first and second cavities formed within the housing where the first cavity is configured to receive a first earbud in the pair of earbuds and the second cavity is configured to receive a second earbud in the pair of earbuds. A lid operable between a closed position where the lid is aligned over the first and second cavities and an open position where first and second cavities are exposed enabling the pair of earbuds to be removed from the housing can be attached to the housing, and the lid can include an electrically conductive and compliant region facing the first and second cavities when the lid is in the closed position. Charging circuitry can coupled to each of the first and second pairs of electrodes. In some embodiments the charging includes a high frequency inverter configured to receive a DC power signal and output a high frequency AC signal to each of the first and second pairs of electrodes. 
     Some embodiments pertain to an earbud that includes electrodes in a speaker housing portion. The earbud can include a housing having a speaker housing portion with an audio exit and a stem housing extending away from the speaker portion. A speaker operatively coupled to emit sound through the audio exit can be disposed in the speaker housing portion along with a pair of electrodes, including a first electrode and a second electrode. The earbud can further include a battery; a wireless antenna and circuitry coupled to receive a wireless signal over the antenna; and charging circuitry coupled between the battery and the pair of electrodes. The charging circuitry configured to charge the battery from power received capactively over the pair of electrodes. 
     In some embodiments an audio system is provided that includes both a case and a pair of earbuds, or other portable listening device, as disclosed herein. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a simplified perspective view of an earbud case according to some embodiments of the disclosure; 
         FIG. 2  is a simplified cross-sectional view of the earbud case shown in  FIG. 1 ; 
         FIG. 3A  is a simplified cut-away perspective view of one of the earbuds shown in  FIG. 1  and a portion of the earbud case surrounding the depicted earbud; 
         FIG. 3B  is a simplified cross-sectional view of a portion of  FIG. 3A ; 
         FIGS. 3C and 3D  are simplified cross-sectional views of a portion of an earbud  125  and earbud case, respectively, according to embodiments of the disclosure; 
         FIG. 4  is a simplified cross-sectional view of one of the earbuds and a portion of the earbud case shown in  FIG. 3A ; 
         FIG. 5  is an enlarged diagram of a portion of the earbud and earbud case shown in  FIG. 4 ; 
         FIG. 6  is a simplified block diagram depicting various components of an earbud case according to some embodiments of the disclosure; 
         FIG. 7  illustrates a cross-sectional view of an earbud case according to some embodiments of the disclosure; 
         FIG. 8  illustrates a simplified perspective view of an earbud case according to some embodiments of the disclosure; 
         FIG. 9  is a simplified cross-sectional view of the earbud case shown in  FIG. 8 ; 
         FIG. 10A  is a simplified top view of a pair of earbuds according to some embodiments of the disclosure; 
         FIG. 10B  is a simplified top view of a pair of earbuds according to some embodiments of the disclosure; 
         FIG. 11A  illustrates a simplified perspective view of an earbud case according to some embodiments of the disclosure; 
         FIG. 11B  illustrates a simplified perspective view of an earbud case according to some embodiments of the disclosure; 
         FIGS. 12-15  illustrate experimental results according to some embodiments of the disclosure; and 
         FIGS. 16-17  illustrate experimental results according to some embodiments of the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Some embodiments of the present disclosure pertain to a case that can store and wirelessly charge an in-ear listening device, such as a pair of earbuds. Other embodiments of the disclosure pertain to a pair of earbuds or other type of in-ear listening device that can be wirelessly charged by a case according to the present disclosure. 
     In order to better understand and appreciate various embodiments and aspects of the present invention, reference is first made to  FIGS. 1 and 2 .  FIG. 1  illustrates a simplified see-through perspective view of an earbud case  100  according to some embodiments of the disclosure, and  FIG. 2  is a simplified cross-sectional view of earbud case  100 . As shown in the figures, earbud case  100  includes a housing  105  and a lid  110  that can be pivotally coupled to housing  105  by a hinge  112 . Housing  105  can include interior space in which a pair of earbuds  120 ,  125  can be stored. 
     The interior space of housing  105  can define first and second cavities  130 ,  135  (shown in  FIG. 2 ) sized and shaped to accept earbuds  120 ,  125 , respectively. In some embodiments, an insert  115  can bonded to and considered a portion of housing  105  to form cavities  130 ,  135 . Each of the cavities  130 ,  135  can then be defined by a surface of the insert  115  that conforms to the general shape of earbuds  120 ,  125 . For example, insert  115  can define a top surface  118  of housing  105  that includes upper indentations  132 ,  136  that are part of cavities  130 ,  135  and that accept the speaker portions of each earbud. Insert  115  can further include first and second interior tubes  134 ,  138  that extend from cavities  130 ,  135 , respectively, and accept stems  150  of each earbud. 
     Lid  110  can be coupled to housing  105  by a hinge  112  or similar mechanism that enables the lid to be moved between a closed position in which the lid covers the interior space of case  100  including cavities  130 ,  135  and an open position (illustrated in  FIG. 1 ) in which the cavities are exposed to allow a user to place the earbuds  120 ,  125  within case  100  or remove the earbuds  120 ,  125  from the case. While not shown in  FIG. 1 or 2 , earbud case  100  can include a battery, charging circuitry to charge the battery and/or charge earbuds  120 ,  125  stored within the case, and other circuitry and components, some of which are discussed with respect to  FIG. 6 . In some embodiments, each of the earbud housing  105 , lid  110  and insert  115  can be made from a plastic or similar material such as ABS or polycarbonate. Similarly, each earbud  120 ,  125  can include an earbud housing that defines the size and shape of the earbud and can also be made out of a plastic or similar material, including but not limited to ABS or a polycarbonate. In some embodiments, the housing for each earbud  120 ,  125  can include a speaker housing portion and a stem portion that is coupled to and extends away from the speaker housing portion. Speaker housing portion can include an audio exit and a speaker operatively coupled to emit sound through the audio exit. Stem portion can include a battery, wireless antenna, circuitry coupled to receive a wireless signal over the antenna, charging circuitry and other components. Embodiments of the invention are not limited to any particular configuration of components within earbuds  120 ,  125 , however. 
     Case  100  can also include a receptacle connector  140  that has an opening at an exterior surface of case  100  (e.g., the bottom surface as shown in  FIG. 1 ). A suitable plug connector can be inserted in the opening to mate with the receptacle connector and transfer power to case  100  (e.g., from a charging cable) to charge a battery (not shown) within case  100  and/or to transfer data between case  100  and another device. Receptacle connector  140  can be, for example, a mini-USB connector, a Lightning connector developed by Apple Inc., the assignee of the present application, a USB-C connector, or any other appropriate connector. In other embodiments, connector  140  is optional and case  100  can instead receive power to charge an internal battery from a wireless power source. For example, in some embodiments case  100  can include one or more wireless power receiving coils that can wirelessly receive power from one or more wireless power transmit coils within a wireless charging mat or similar device. 
     According to embodiments of the disclosure, earbud case  100  can wirelessly charge each of the earbuds  120 ,  125 . Earbuds  120 ,  125  are relatively small devices that include various electronics and audio components as described below with respect to  FIG. 6  to maximize a user&#39;s experience using earbuds  120 ,  125 . Thus, in some embodiments there is very limited space available for such wireless charging circuitry and the inventors have found that capacitive coupling is more space efficient than inductive coupling in such a constrained environment. Towards this end, in some embodiments, earbud case  100  can include multiple capacitive plates that are positioned within the case to align with electrodes in each respective earbud  120 ,  125 . 
     For example, as shown in  FIGS. 1 and 2 , each earbud  120 ,  125  can include an elongated stem  150  that extends away from the ear portion  160  of the bud, which in some embodiments can include the microphone, battery, antenna and other components of the earbud. Each earbud  120 ,  125  can include a pair of electrodes embedded within the stem. For example, as shown in  FIG. 2 , earbud  120  can includes electrodes  122  and  124 , while earbud  125  can include electrodes  126  and  128 . 
     Earbud case  100  can include electrodes embedded within the case at locations adjacent to the earbud electrodes  122 ,  124  and  126 ,  128  when the earbuds are fully inserted into cavities  130 ,  135 . For example, as shown in  FIG. 2 , earbud case  100  can include electrodes  142  and  144  disposed adjacent to electrodes  122  and  124 , respectively, in earbud  120  when earbud  120  is fully inserted into cavity  130 . Similarly, earbud case  100  can also include electrodes  146  and  148  disposed adjacent to electrodes  126  and  128 , respectively, in earbud  125  when earbud  125  is fully inserted into cavity  135 . 
     To maximize power transfer between electrodes in each of the earbuds  120 ,  125  and corresponding electrodes in case  100 , embodiments of the invention minimize the distance between the electrodes in the earbuds and the electrodes in the case as described below. In some embodiments earbud electrodes  122 ,  124  and  126 ,  128  conform in shape to the earbud housing portion of each earbud stem  150 . For example, if stems  150  have a cylindrical cross-section, each of the earbud electrodes  122 ,  124  and  126 ,  128  can have a similar cylindrical cross-section. If stems  150  have an oval or other cross-sectional shape, each of the earbud electrodes can have a matching cross-sectional shape. 
     Similarly, the electrodes  142 ,  144 ,  146  and  148  within case  100  can conform to the shape of cavities  130 ,  135  in the area in which the electrodes are positioned. In some embodiments the cross-section of the portion of each cavity  130 ,  135  that accepts the earbud stem  150  generally matches the cross-section of stem  150  and thus, when earbud stems  150  have a cylindrical cross-sectional shape, case electrodes  142 ,  144 ,  146  and  148  can also have a cylindrical cross-section with each case electrode annularly surrounding its respective earbud electrode. When stems have an oval or other cross-sectional shape, the case electrodes can have a matching cross-sectional shape as well. Further details of electrodes within earbud case  100  and earbuds  120 ,  125  are discussed below with respect to  FIGS. 3A-3D, 4 and 5 . 
       FIG. 3A  is a simplified exploded perspective cut-away view of a portion of cavity  135  in the earbud case and of earbud  125  shown in  FIG. 1 , and  FIG. 3B  is an exploded side plan cross-sectional view of a portion of the earbud cavity  135  and  125  shown in  FIG. 3B . In order to more clearly illustrate concepts of embodiments of the invention, neither of  FIG. 3A or 3B  are drawn to scale and neither of  FIG. 3A or 3B  depict the housing of the earbuds or earbud case. For example, as discussed above, earbud  125  can include an earbud housing made from a plastic such as ABS or a polycarbonate or any suitable material. The housing provides the earbud with structure and forms a cavity in which the various components of the earbud (e.g., circuitry, speakers, etc.) are disposed. The earbud housing will have a certain thickness to it that provides desired structure and sufficient rigidity to the earbud. Similarly, housing  105  provides structure to case  100  and defines internal sections of the case in which its electrical components are housed. Housing  105  also includes surfaces (e.g., via insert  115 ) that define cavities  130 ,  135 . The various surfaces of housing  105  and the earbud housing are not depicted in  FIGS. 3A and 3B  and are instead discussed with respect to  FIGS. 3C and 3D . 
     As shown in  FIGS. 3A and 3B , earbud  125  can include first and second electrodes  126 ,  128  that are separated by a gap  340 . Each of the electrodes  126 ,  128  can have a cylindrical cross-sectional shape (as shown in  FIG. 3A ) that conforms to the shape of the stem  150  of earbud  125 . In some embodiments gap  340  can be an air gap and in other embodiments, gap  340  can be filled with an appropriate electrically insulating material. Similarly, electrodes  146 ,  148  within the earbud case can be separated from each other by a gap  345  and have a cross-sectional shape that matches (albeit with a slightly larger radius) that of electrodes  126 ,  128 . Gap  345  can be an air gap or can be filled with an electrically insulating material similar to gap  340 . 
     When earbud  125  is fully inserted within cavity  135  (i.e., in a “charging position”), the earbud electrodes  126 ,  128  align with earbud case electrodes  146 ,  148  forming a first capacitor between electrodes  126 ,  146  and a second capacitor between electrodes  128 ,  148 . The two capacitors can form part of an electric circuit as discussed below with respect to  FIG. 6 , enabling power to be transferred from the earbud case to the earbud. The amount of power that can be transferred depends, among other factors, on the distance between the two electrodes in each capacitor. A tighter spacing between the electrodes results in more efficient power transfer. 
     In the charging position, electrodes  126  and  128  are separated from, electrodes  146 ,  148  of case  100  by an air gap  330 . Earbuds  120  and  125  and cavities  130 ,  135  can be manufactured so that, while allowing for manufacturing tolerances, the air gap  330  between adjacent electrodes is minimized when the earbuds are in the charging position in order to decrease the distance between each of the electrode pairs while still allowing the earbud to be placed within cavity  135 . In some embodiments the earbuds and case are manufactured to tolerances that provide an air gap of between 5-20 microns. 
     Various embodiments of the disclosure include one or more additional design features that further minimize and/or control the space between the adjacent electrodes in each of the two capacitors. One such additional design feature includes minimizing the thickness of a very thin dielectric skin formed over the electrodes on the exterior surface of the earbud, the interior surface of the earbud receiving cavity or both. For example, in the embodiment shown in  FIGS. 3A and 3B , earbud  125  can include a thin dielectric layer  310  over electrodes  126  and  128  while receiving cavity  135  can include a thin dielectric layer  320  over electrodes  146 ,  148 . Another such design feature includes a certain amount of draft within the stem portion of each earbud receiving cylinder  134 ,  138  as discussed below with respect to  FIG. 7 . 
     In some embodiments, each of the dielectric skins  310  and  320  can be a thin electrically insulating material that can be, for example, selected for cosmetic reasons. Examples of suitable dielectric skins are various polymer materials. In other embodiments, each of the dielectric skins  310  and  320  can be a high dielectric constant material, such as a high dielectric constant polymer, ceramic or other material with a dielectric constant of greater than 5 that enables increased capacitance and thus improved charging capacity. While embodiments of the disclosure are not limited to any particular thickness for layers  310  or  310 , in some embodiments either or both of layers  310  and  320  are between 5-25 microns thick, and in some embodiments either or both of layers  310  and  320  are between 5-10 microns thick. Each of layers  310  and  320  can be formed over electrodes  126 ,  146 , respectively, with an overmolding process or other appropriate techniques. 
       FIGS. 4 and 5  are illustrations that further depict the relationship between adjacent electrodes  128  and  148  when earbud  125  is fully inserted within its cavity  135  according to some embodiments. Specifically,  FIG. 4  is a simplified cross-sectional view taken along the lines shown in  FIG. 3A  of electrodes  128 ,  148  and  FIG. 5  is an exploded view of a portion shown in  FIG. 4 . As shown in  FIGS. 4 and 5 , the distance between adjacent electrodes  128 ,  148  is determined by the thickness of dielectric layers  310  and  320  as well as gap  330 . For ease of illustration, the housings of earbud  125  and case  100  are not depicted in either of  FIG. 4 or 5  just as the housings are not depicted in  FIG. 3A or 3B . 
     As discussed above, in some embodiments each of the earbuds and the earbud case include a housing that is not shown in  FIG. 3A or 3B . For example, as shown in  FIG. 3C , which is a simplified cross-sectional view of a portion of earbud  125 , electrodes  126 ,  128  can be formed over a housing  350 . Housing  350  can be made from an plastic such as ABS or a polycarbonate or another suitable electrically insulative material. Housing  350  can be considerably thicker than either of electrodes  126 ,  128  and layer  310  providing the earbud with structure and forming a cavity within the earbud in which the various components of the earbud (e.g., a battery, charging circuitry, etc.) are disposed. Since electrodes  126 ,  128  are formed over the housing, one or both of the electrodes can encircle or otherwise surround the earbud components located in the cavity. 
     Similarly, as shown in  FIG. 3D , which is a simplified cross-sectional view of a portion of insert  115 , electrodes  146 ,  148  can be formed over a housing  360 . Housing  360  can be considerably thicker than either of electrodes  146 ,  148  and layer  320  providing the earbud case with structure and forming one or more interior cavities within the earbud case in which various electrical components can be housed. 
     Electrodes  126 ,  128  and  146 ,  148  (as well as electrodes  122 ,  124  and  142 ,  144 ) can be formed using a variety of different techniques and in some embodiments, can be relatively thin, for example, 0.1-50 microns. In some embodiments the electrodes can be deposited directly over a surface of housings  350  and/or  360  using sputtering or electrodeposition techniques. In other embodiments each electrode can be a relatively thin metal piece that is attached to its respective housing with an appropriate adhesive and in still other embodiments, each electrode can be formed from a thin metalized mylar sheet or similar conductive material that is adhered to its respective housing. Additionally, in some embodiments one or both of dielectric layers  310  or  320  is optional. For example, in some embodiments earbud  125  (and earbud  120 ) do not include a thin cosmetic dielectric layer  310  and instead electrodes  126 ,  128  (and  122 ,  124 ) are at the exterior surface of the earbud and can, optionally, form a cosmetic surface as well. In other embodiments case  100  does not include a cosmetic overmold over electrodes  146 ,  148  (and  142 ,  144 ) within cavities  135  (and  130 ). Such embodiments can further reduce the spacing between the two adjacent electrodes that make up each capacitive pair (e.g., electrodes  126 ,  146  and  128 ,  148 ). 
     Reference is now made to  FIG. 6 , which is a simplified block diagram depicting various components of an earbud charging system  600  according to some embodiments of the disclosure. As shown in  FIG. 6  charging system  600  includes an earbud  610  and an earbud case  620 . Earbud  610  can be, for example, any of the earbuds described herein such as earbuds  120  or  125  as well as other suitable earbuds. Earbud case  620  can be, for example, any of the earbud cases described herein such as earbud case  100 , as well as other suitable earbud cases. 
     While not shown in  FIG. 6 , earbud case  620  can include one or more cavities that are sized and shaped to receive earbud  610  such that when the earbud is within the cavity, electrodes in earbud  610  align with electrodes in earbud case  620  forming a capacitively-coupled electric circuit that enables the earbud case to charge a battery within the earbud. Thus, when earbud  610  is inserted within the receptacle cavity of earbud case  620 , an electrical circuit between earbud  610  and earbud case  620  is formed within charging system  600  that includes capacitors C 1  and C 2  and enables power to be transferred from earbud case  620  to earbud  610 . Each of capacitors C 1  and C 2  are formed by a pair of electrodes including a first electrode within earbud  610  and a second electrode within earbud case  620 . As an example where earbud  610  is representative of earbud  125  and earbud case  620  is representative of earbud case  100 , capacitor C 1  can be formed from electrode  128  within the earbud and electrode  148  in the earbud case. Similarly, capacitor C 2  can be formed from electrode  126  in the earbud and electrode  146  within the earbud case. 
     In some embodiments, capacitive charging of earbud  610  can be initiated once the earbud is inserted into the earbud case and a circuit through capacitors C 1  and C 2  is formed. In other embodiments charging can be delayed until a sensor (not shown) within case  620  detects that an earbud  610  is fully inserted in the cases earbud receiving cavity. Such embodiments can be particularly useful, for example, when the electrodes on the earbud and/or case are at the exterior surface of the earbud or case in order to prevent possible shorting when buds are not inserted properly. As one specific implementation example, case  620  can measure the impedance at each earbud and can turn its charging circuitry on only when the correct impedance is detected. As another implementation example, case  620  can initiate charge only when a lid of the case is closed and one or more earbuds are fully inserted within the case or when an optical sensor positioned within the cavity detects the insertion of earbud  610 . 
     Earbud case  620  can include, among other elements, a DC power source  622 , an inverter  624  and an impedance matching/tuning network  626 . DC power source can be, for example, a battery within case  620  or could be a constant DC voltage received from an outside power source, such as a 5V power signal received through a receptacle connector (not shown) within case  620 . DC power source  622  is coupled to inverter  624 , which can be a high frequency inverter that converts the DC power signal received from power source  622  to an AC signal. In some embodiments, high frequency inverter converts the DC power signal it receives to an AC signal in the megahertz range of, for example, 2-50 MHz, and, in certain specific embodiments, high frequency inverter  624  converts the DC signal into a 5 MHz or a 6.78 MHz signal. Inverter  624  is, in turn, coupled to impedance matching/tuning network  626  that helps maximize power transferred from earbud case to the earbud over the capacitors C 1  and C 2 . 
     Earbud  610  includes, among other elements, a rectifier  612 , battery charging circuitry  614  and a battery  616 . Rectifier  612  is coupled at an input to receive an alternating current from the capacitors and converts the AC current to a direct, DC current. Battery charging circuitry is coupled at an input to receive the DC current from rectifier  612  and coupled at an output to charge battery  616 . The maximum charging power on earbud  610  can be determined by the following formula:
 
Maximum Charging Power= C×V   in   ×V   max ×2π f   (1)
 
where C is the capacitance between the earbud and earbud case electrodes, V in  is the RMS value of the input voltage, V max  is the RMS value of the maximum voltage allowed across each coupling capacitor and f is the operation frequency of the high frequency inverter. The capacitance generated by capacitors C 1  and C 2  is inversely related to the spacing between the electrode pairs of the earbud  610  and earbud case  620 . Thus, as described above, various embodiments of the invention adopt features that are intended to minimize this spacing.
 
       FIG. 7  depicts another embodiment that helps minimize the spacing between electrode pairs by reducing or eliminating the airgap formed between the electrode in an earbud and its corresponding electrode in the earbud case for a given electrode pair. For example, in embodiments depicted in  FIGS. 1-5  above, the cavities  130 ,  135  within case  100  have a straight-wall cylindrical shape that is slightly larger than the straight-wall cylindrically shaped stems  150  of earbuds  120 ,  125 . The straight walls require at least a small tolerance in the radius to ensure that the stem of each earbud  120 ,  125  fits within its respective cavity  130 ,  135 . In some embodiments of the disclosure, the earbud stems and case cavities can include walls with a slight draft that enables a tighter fit between the stem and the cavity without worrying about the associated tolerances.  FIG. 7  depicts such an embodiment where a case  700  includes first and second cavities  730  and  735 , respectively, each of includes a slight draft (taper) in which each cavity becomes progressively narrower along its depth. Earbuds  720  and  725  can then include stems  750  that have a matching angle or draft. Thus, each earbud  720  and  725  can be fully inserted into its respective cavity  730 ,  735  until the side surfaces of its earbud stem  750  come into physical contact with the interior surfaces of the cavity. When manufactured to sufficiently high standards, such embodiments can results in essentially no gap  330  (or a very minimal gap at portions of stem  750  due to manufacturing variations) between each earbud stem and the interior surface of its surrounding cavity. 
     While  FIGS. 1-5 and 7  discussed above depict embodiments of the invention in which the various electrodes are located at specific positions along the stem of the earbuds and at matching locations in the earbud case and in which the electrodes have a particular size and shape, the invention is not limited to any particular electrode configuration. In other embodiments, the electrodes can be located at different positions than those discussed above and/or have different shapes or configurations. For example, in some embodiments one or more of the electrodes can be located in the speaker housing portion of each earbud and in the lid portion of the earbud case as illustrated in  FIGS. 8-10 . 
       FIG. 8  illustrates a simplified perspective view of an earbud case  800  according to some embodiments of the disclosure that includes electrodes in the case lid. As shown in  FIG. 8 , case  800  includes a primary housing  805  and a lid  810  that can be pivotably coupled to housing  805  by a hinge (not labeled). Housing  805  can include interior space in which a pair of earbuds  820 ,  825  can be stored. Each of electrodes  820 ,  825  can include a speaker housing  822  and a stem  824 . In some embodiments a speaker and audio port are housed and formed in speaker housing  822  while battery charging circuitry, a battery, a wireless antenna and other components are housed within stem  824 . 
     Instead of having electrodes within the stem of earbuds  820 ,  825 , each earbud  820 ,  825  can include a pair of electrodes within speaker housing portion  822 . For example, as shown in  FIG. 9 , which is a simplified cross-sectional view of the earbud case shown in  FIG. 8 , earbud  820  can include a pair of electrodes  842 ,  844  and earbud  825  can include a pair of electrodes  846 ,  848 . Each of the electrodes  842 ,  844 ,  846  and  848  can be covered by a thin dielectric skin (not labeled) as described with respect to  FIGS. 3A-3D . Electrodes  842 - 448  can be arranged in any suitable manner. As one example, electrodes  842   a ,  844   a  and  846   a ,  848   a  can be arranged opposite each other along a direction X of the earbud speaker housing  822  as shown in  FIG. 10A , which is a simplified top view of a pair of earbuds  820   a ,  825   a  according to some embodiments of the disclosure positioned within cavities formed within earbud housing  805 . As another example, electrodes  842   b ,  844   b  and  846   b ,  848   b  can be arranged opposite each other along a direction Y of the earbud speaker housing  822  as shown in  FIG. 10B , which is a simplified top view of a pair of earbuds  820   b ,  825   b  according to some embodiments of the disclosure positioned within cavities formed within earbud housing  805 . Embodiments of the disclosure are not limited to any particular arrangement of the electrodes, however, and other arrangements are possible. 
     Referring back to  FIGS. 8 and 9 , earbud case  800  can include earbud receiving cavities  830  and  835  to receive earbuds  820 ,  825 , respectively, and can further include multiple electrodes within a conformable region  850  of lid  810 . Conformable region  850  can be made from an electrically conductive, relatively soft compliant material that conforms in shape to an upper surface of earbuds  820 ,  825  when the lid is closed and the earbuds are in the receiving cavities  830 ,  835 . The conformable nature of region  850  enables the region to match the shape of complex surfaces, such as an upper curved surface of an earbud. Thus, once lid  810  is closed covering earbuds  820 ,  825  within case  800 , conformable region  850  conforms to and is in direct contact with the upper surface of earbuds  820 ,  825  with essentially no airgap between region  850  and electrodes  842 - 848  (as shown in  FIG. 9 ) enabling highly efficient transfer of power between electrodes  842 - 848  and electrodes within region  850 . 
     In some embodiments conformable region  850  can be a singular region made from an electrically conductive material having anisotropic conductivity that conducts current in a single direction. For example, conformable region  850  can be a flexible polymer material having graphite tubes or particles embedded within in material in a pattern that forces current through the material along a particular axis or direction (e.g., from the surface of region  850  to an electrical connection within the lid leads to impedance matching/tuning network  626  of  FIG. 6 ). The anisotropic nature of conformable region  850  prevents current from leaking in a lateral direction that could otherwise short adjacent electrodes in an earbud together and does not require an insulative layer formed over region  850 . Thus, in effect, the anisotropic nature of the conductive material in region  850  enables the formation of separate charging circuits for each earbud. That is, portions of conformable region  850  adjacent to electrodes  842 ,  844  form first and second electrodes within region  850  that, when operatively coupled to electrodes  842 ,  844  create capacitors C 1  and C 2  for earbud  820  as described with respect to  FIG. 6  for a first charging circuit. Similarly, portions of conformable region  850  adjacent to electrodes  846 ,  848  form third and fourth electrodes within region  850  that, when operatively coupled to electrodes  846 ,  848  create capacitors C 1  and C 2  for earbud  825  as described with respect to  FIG. 6  for a second charging circuit. 
     In some embodiments, instead of a single, large conformable region  850 , multiple distinct conformable electrodes can be formed within lid  810  that are aligned with electrodes in the earbuds that are intended to be stored in the case. For example, in some embodiments where earbuds  820 ,  825  include electrodes located at positions depicted in  FIG. 10A , a case for a pair of earbuds can include multiple conformable electrodes spaced apart along a width of lid  810 . Such an embodiment is as shown in  FIG. 11A  where earbud case  855  includes conformable electrodes  852 ,  854  that aligned with electrodes  842   a ,  844   a  of earbud  820   a  as shown in  FIG. 10A . Case  855  can also include conformable electrodes  856 ,  858  that are aligned with electrodes  846   a ,  848   a  in earbud  825   a . In some embodiments, lid  810  can include a contoured inner surface that faces the earbuds when the lid is in the closed position and generally matches the shape of the earbuds without coming in contact with the earbuds. Conformable regions  852 - 858  are electrically separated from each other by the inner surface and can be located at locations along the contoured inner surface that align with the electrodes of the earbuds and come in contact with the earbuds when the lid is in the closed position. Because the electrodes in the case in these embodiments are separated from each other, the conformable material does not need to have anisotropic conductivity and each of the electrodes  852 - 858  can be made from a flexible conductive material, such as the material used in GORE® SMT EMI gaskets as well as other suitable materials. 
     As another example, a case for a pair of earbuds can include multiple conformable regions spaced apart along a depth of lid  810 . Such an embodiment is as shown in  FIG. 11B  where earbud case  865  includes conformable electrodes  862 ,  864  that align with electrodes  842   b ,  844   b  of earbud  820   b  as shown in  FIG. 10B . Case  865  can also include conformable electrodes  856 ,  858  that are aligned with electrodes  846   b ,  848   b  in earbud  825   b.    
     To demonstrate the effectiveness of various embodiments of the invention, the inventors performed a number of simulations using finite element analysis (FEA) software from Ansys Maxwell.  FIGS. 12-17  illustrate results of the simulations. In a first series of simulations depicted in  FIGS. 12 and 13 , capacitance was calculated based on an earbud case and earbud design in accordance with embodiments described with respect to  FIGS. 1-5  in which the earbud and earbud case each had a thin (10 micron) cosmetic dielectric layer formed over the bud side and case side electrodes. The simulations varied the dielectric constant of the dielectric from a k value of 5 to 30 over each of three different airgap sizes (1 micron, 5 microns and 10 microns). 
     In a second series of simulations depicted in  FIGS. 14 and 15 , capacitance was calculated based on an earbud case and earbud design in accordance with embodiments described with respect to  FIGS. 1-5  in which the earbud case each had a thin (10 micron) cosmetic dielectric layer formed over the earbud case dielectric and the earbud did not include a cosmetic dielectric layer covering the bud side electrodes. As with the simulations set forth in  FIGS. 12 and 13 , the  FIGS. 14 and 15  simulations also varied the dielectric constant of the dielectric from a k value of 5 to 30 over each of three different airgap sizes (1 micron, 5 microns and 10 microns). 
     Based on the results of the simulations depicted in  FIGS. 12-15 , the inventors have shown that higher dielectric material helps to increase the capacitance between the earbud electrodes and earbud case electrodes. Reducing the size of the airgap is even more effective at increasing capacitance, however. Larger capacitance between the electrodes can enable sufficient charging power with an acceptable level of inverter voltage, operation frequency and voltage between the electrodes. 
       FIGS. 16 and 17  depict the results of additional simulations where capacitance was calculated based on an earbud case and earbud design in accordance with embodiments described with respect to  FIGS. 8 and 9 . In the  FIGS. 16 and 17  simulations, a 50 micron dielectric layer was modeled over the earbud electrodes and the earbud case included a flexible conductive materials as the conformable electrode in the lid earbud case. Since the conformable electrode is generally in physical contact with the earbuds, a 1 micron airgap was used in the simulation and the simulations varied the dielectric constant of the dielectric from a k value of 5 to 30. Each of the simulations depicted in  FIGS. 12-17  demonstrate that embodiments of the invention can generate sufficient capacitance between the electrodes to sufficiently charge batteries in the earbuds using the techniques described herein. A person of skill in the art will recognize that tradeoffs can be made at the design states between the various variables that impact charging power to ensure safe voltage levels during operation, system efficiency and adequate thermal performance during operation. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings. 
     For example, while the various examples set forth in the disclosure above focused on cases for a pair of earbuds and on various earbud designs, embodiments of the invention are not limited to only earbuds and can be used for other types of portable listening devices. Additionally, while the specific examples of earbuds (and corresponding earbud cases) presented above according to embodiments of the disclosure either included two electrodes in the stem of the earbud or two electrodes in the speaker housing of the earbud, embodiments of the invention are not limited to such. In other embodiments, a first electrode can be formed in the stem of an earbud while a second electrode can be formed in the speaker housing. Additionally, some embodiments can include just a single capacitive electrode and complete an electrical charging circuit, such as the circuit shown in  FIG. 6 , with an electrical contact, such as a copper or other appropriate metal or plated contact. For example, in some embodiments an earbud can include a single contact at the bottom of stem  150  and an electrode either within the stem or within the speaker housing. In all such embodiments, the earbud case can include electrodes and/or contacts at locations that align with the electrodes and/or contacts of the earbuds as appropriate to enable charging. 
     In still other embodiments, components of an earbud can be arranged differently than described in the examples above and/or the earbuds can include fewer or more components. For example, while earbuds described above included a battery in a stem portion of the earbud, in other embodiments a battery can be formed in the speaker housing portion. And, in some embodiments, the earbuds may not include a stem at all. As another example, in some embodiments earbuds according to the present disclosure can include deformable earbud tips that enable the earbud to better fit in a user&#39;s ear. In still other examples, earbuds according to the disclosure can include a touch interface at an external surface of the housing. 
     Additionally, while the various embodiments and examples described above were primarily focused on an earbud case for storing earbuds, embodiments of the disclosure are not limited to such and the techniques of the disclosure described above are equally applicable to other portable electronic devices including wearable devices, smart phones, and tablet computers among others. Also, other embodiments of the disclosure are applicable to cases for other types of in-ear listening devices. For example, in one embodiment, case  100  described in  FIG. 1  can be a case for a single in-ear listening device instead of a pair of earbuds. In such an embodiment, a single cavity can formed within housing  105  that is sized and shaped to hold the in-ear listening device. Similarly, in other embodiments, case  100  can be sized and shaped to hold other types of portable listening devices besides earbuds including hearing aids, headphones and the like. For example, in some embodiments a case for a portable listening device is provided. The case can include a housing having a cavity formed within the housing and configured to receive the portable listening device; a lid attached to the housing and operable between a closed position where the lid is aligned over the cavity and an open position where cavity is exposed enabling the portable listening device to be removed from the housing; a pair of electrodes positioned within the housing adjacent to the first cavity; and charging circuitry coupled to the pair of electrodes to charge a battery of the portable listening device when the portable listening device is received within the cavity. The charging circuitry can include a high frequency inverter coupled to receive a DC power signal and output a high frequency AC signal to the pair of electrodes. These embodiments, others and their equivalents are possible in view of the teaching of the present disclosure.

Metadata:
Filing Date: 20180827
Publication Date: 20200818
Grant Date: 20200818
Priority Date: 20180827
Inventors: DANG, ZHIGANG
NUSSBAUM, MICHAEL B.
Assignee: APPLE INC
CPC Classifications: [{"code": "H02J50/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/05", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1016", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/1025", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02J50/05", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/05", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/028", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1025", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/1016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/028", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/05", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/025", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/1025", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 69586806