PATENT DOCUMENT

Publication Number: US-12149093-B2
Application Number: US-202016987691-A
Country: US
Kind Code: B2

Title: Device coupling for wireless charging

Abstract:
Electronic apparatuses according to embodiments of the present technology may include an electronic device a first surface and a second surface opposite the first. The electronic device may include a battery and a wireless charging coil within an interior volume of the device. The electronic device may include a first magnetic conductor and positioned between the battery and the wireless charging coil. The electronic device may also include an integrated circuit coupled with the battery and the wireless charging coil. The apparatuses may include a case extending about the electronic device. The case may be characterized by a first surface and a second surface. The case may be characterized by a thickness between the first surface of the case and the second surface of the case. The case may include a second magnetic conductor incorporated within the thickness of the case at the second surface of the case.

Claims:
What is claimed is: 
     
       1. An electronic apparatus comprising:
 an electronic device comprising a display on a first surface of the electronic device and a second surface opposite the first surface of the electronic device, the electronic device including: 
 a battery, 
 a wireless charging coil positioned proximate the second surface of the electronic device within an interior volume defined by the electronic device, 
 a first magnetic conductor housed within the interior volume of the electronic device and positioned between the battery and the wireless charging coil, wherein the wireless charging coil is seated on the first magnetic conductor, and 
 an integrated circuit coupled with the battery and the wireless charging coil, the integrated circuit configured to receive wireless power using the wireless charging coil; and 
 a case extending about the electronic device and contacting the electronic device at a first surface of the case, wherein the case includes a second surface of the case opposite the first surface of the case, and wherein the case has a thickness defined between the first surface of the case and the second surface of the case, the case including: 
 a second magnetic conductor incorporated within the thickness of the case and defining an aperture that is at least partially aligned with the wireless charging coil and is arranged to direct magnetic flux received from a wireless power transmit coil to the wireless charging coil to improve coupling between the wireless power transmit coil and the wireless charging coil. 
 
     
     
       2. The electronic apparatus of  claim 1 , wherein the first magnetic conductor comprises a ferrite material or a nanocrystalline foil material. 
     
     
       3. The electronic apparatus of  claim 2 , wherein the first magnetic conductor comprises a nanocrystalline foil having between about 2 and about 10 layers of a ferrosilicon-containing material. 
     
     
       4. The electronic apparatus of  claim 3 , wherein the wireless charging coil includes an annular shape comprising an inner annular radius defining an interior cylindrical volume. 
     
     
       5. The electronic apparatus of  claim 4 , wherein additional layers of the ferrosilicon-containing material are disposed within the interior cylindrical volume. 
     
     
       6. The electronic apparatus of  claim 1 , wherein the second magnetic conductor comprises a ferrite material or a nanocrystalline foil material. 
     
     
       7. The electronic apparatus of  claim 6 , wherein the second magnetic conductor comprises a soft ferrite material. 
     
     
       8. The electronic apparatus of  claim 6 , wherein the second magnetic conductor comprises a cylindrical post extending for a length of more than 50% of the thickness of the case proximate the second surface of the case. 
     
     
       9. The electronic apparatus of  claim 8 , wherein the second magnetic conductor further comprises an annular ring extending about the cylindrical post, and wherein an annular gap exists between the cylindrical post and the annular ring of the second magnetic conductor. 
     
     
       10. The electronic apparatus of  claim 9 , wherein the wireless charging coil includes an annular shape having a radial length from an inner annular radius of the wireless charging coil to an outer annular radius of the wireless charging coil along a radius of the wireless charging coil. 
     
     
       11. The electronic apparatus of  claim 10 , wherein the radial length of the wireless charging coil is less than or about a radial length of the annular gap of the second magnetic conductor. 
     
     
       12. The electronic apparatus of  claim 1 , wherein the electronic device comprises a mobile phone or a tablet. 
     
     
       13. An electronic apparatus comprising:
 an electronic device having a graphical display at a first exterior surface of the electronic device and a second exterior surface opposite the first exterior surface of the graphical display, wherein the electronic device defines a volume between the first exterior surface and the second exterior surface; 
 a first magnetic conductor positioned within the volume of the electronic device and defining a recessed annular ledge disposed within the volume of the electronic device; 
 an annular wireless charging coil positioned within the volume of the electronic device and seated on the recessed annular ledge; 
 a case coupled to the electronic device and including a first surface extending across and contacting the second exterior surface of the electronic device, wherein the case further includes a second surface opposite the first surface, and wherein a thickness of the case is defined between the first surface of the case and the second surface of the case; and 
 a second magnetic conductor integrated within the case and defining an aperture that is at least partially aligned with the annular wireless charging coil and is arranged to direct magnetic flux received from a wireless power transmit coil to the annular wireless charging coil to improve coupling between the wireless power transmit coil and the annular wireless charging coil. 
 
     
     
       14. The electronic apparatus of  claim 13 , wherein the case comprises a rubber material or plastic between the first surface of the case and the second surface of the case. 
     
     
       15. The electronic apparatus of  claim 13 , wherein the electronic device further comprises a metal support plate seated proximate the second surface of the electronic device, wherein the metal support plate comprises an aperture positioned in line with the first magnetic conductor and the annular wireless charging coil. 
     
     
       16. The electronic apparatus of  claim 13 , wherein the first magnetic conductor and the second magnetic conductor comprise a soft ferrite material or a nanocrystalline foil material. 
     
     
       17. The electronic apparatus of  claim 13 , wherein the second magnetic conductor comprises a cylindrical post extending for a length of more than 50% of the thickness of the case, and wherein the second magnetic conductor extends from the second surface of the case towards the first surface of the case. 
     
     
       18. The electronic apparatus of  claim 13 , wherein the second magnetic conductor comprises a cylindrical post and an annular ring extending about the cylindrical post, wherein an annular gap exists between the cylindrical post and the annular ring of the second magnetic conductor, and wherein the second magnetic conductor extends from the first surface of the case towards the second surface of the case. 
     
     
       19. A wireless charging system comprising:
 a first electronic device comprising: 
 a case extending at least partially about the first electronic device, 
 a battery housed within the first electronic device, 
 a first wireless charging coil housed within the first electronic device, 
 a first magnetic conductor housed within the first electronic device and positioned between the battery and the first wireless charging coil, wherein the first wireless charging coil is seated on the first magnetic conductor, and 
 a second magnetic conductor integrated within the case proximate the first wireless charging coil and defining an aperture that is axially aligned with the first magnetic conductor; and 
 a second electronic device comprising: 
 a second wireless charging coil configured to operate in a wireless charging transmission mode, and 
 at least one hard magnet within the second electronic device, 
 wherein the second magnetic conductor is arranged to direct magnetic flux received from the second wireless charging coil to the first wireless charging coil to improve coupling between second wireless charging coil and the first wireless charging coil. 
 
     
     
       20. The wireless charging system of  claim 19 , wherein the first magnetic conductor and the second magnetic conductor comprise a soft ferrite material or a nanocrystalline foil material. 
     
     
       21. The electronic apparatus of  claim 1  wherein the second magnetic conductor comprises an annular ring having an inner diameter, and the inner diameter is at least partially aligned with the wireless charging coil. 
     
     
       22. The electronic apparatus of  claim 1  wherein the first magnetic conductor has a diameter greater than a diameter of the wireless charging coil such that the first magnetic conductor overhangs the wireless charging coil. 
     
     
       23. The electronic apparatus of  claim 1  wherein the second magnetic conductor comprises an annular ring having an inner diameter, the inner diameter is at least partially aligned with the wireless charging coil, and the first magnetic conductor overhangs the wireless charging coil to align with the annular ring of the second magnetic conductor.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of priority to U.S. Provisional Application No. 62/885,433, filed Aug. 12, 2019, the contents of which is hereby incorporated by reference in its entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     The present technology relates to wireless charging systems. More specifically, the present technology relates to wireless charging system configurations, components, and characteristics. 
     BACKGROUND 
     Wireless charging is useful for a variety of devices. As electronic devices in which wireless charging components are housed reduce in size, the available space for materials may be limited, which may affect operational performance. 
     SUMMARY 
     Electronic apparatuses according to embodiments of the present technology may include an electronic device having a display on a first surface of the electronic device. The electronic device may be characterized by a second surface opposite the first surface of the electronic device. The electronic device may include a battery, and a wireless charging coil positioned proximate the second surface of the electronic device within an interior volume defined by the electronic device. The electronic device may include a first magnetic conductor housed within the interior volume of the electronic device and positioned between the battery and the wireless charging coil. The wireless charging coil may be seated on the first magnetic conductor. The electronic device may also include an integrated circuit coupled with the battery and the wireless charging coil. The integrated circuit may be configured to receive wireless power using the wireless charging coil. The apparatuses may include a case extending about the electronic device and contacting the electronic device at a first surface of the case. The case may be characterized by a second surface of the case opposite the first surface of the case. The case may be characterized by a thickness between the first surface of the case and the second surface of the case. The case may include a second magnetic conductor incorporated within the thickness of the case at the second surface of the case. 
     In some embodiments, the first magnetic conductor may be or include a ferrite material or a nanocrystalline foil material. The first magnetic conductor may include a nanocrystalline foil having between about 2 and about 10 layers of a ferrosilicon-containing material. The wireless charging coil may be characterized by an annular shape including an inner annular radius defining an interior cylindrical volume. Additional layers of the ferrosilicon-containing material may be disposed within the interior cylindrical volume. The second magnetic conductor may be or include a ferrite material or a nanocrystalline foil material. The second magnetic conductor may be or include a soft ferrite material. The second magnetic conductor may be or include a cylindrical post extending for a length of more than 50% of the thickness of the case proximate the second surface of the case. The second magnetic conductor may also include an annular ring extending about the cylindrical post. An annular gap may exist between the cylindrical post and the annular ring of the second magnetic conductor. The wireless charging coil may be characterized by an annular shape characterized by a radial length from an inner annular radius of the wireless charging coil to an outer annular radius of the wireless charging coil along a radius of the wireless charging coil. The radial length of the wireless charging coil may be less than or about a radial length of the annular gap of the second magnetic conductor. 
     The electronic device may be or include a mobile phone or a tablet. Some embodiments of the present technology may encompass electronic apparatuses. The apparatuses may include an electronic device having a graphical display at a first exterior surface of the electronic device and a second exterior surface opposite the first exterior surface of the graphical display. The electronic device may define a volume between the first exterior surface and the second exterior surface. The apparatuses may include a first magnetic conductor housed within the volume of the electronic device and defining a recessed annular ledge disposed within the volume of the electronic device. The apparatuses may include an annular wireless charging coil housed within the volume of the electronic device and seated on the recessed annular ledge. The annular wireless charging coil may be characterized by a thickness of less than or about 100 μm. The apparatuses may include a case coupled about the electronic device and characterized by a first surface extending across and contacting the second exterior surface of the electronic device. The case may be further characterized by a second surface opposite the first surface. A thickness of the case may be defined between the first surface of the case and the second surface of the case. The apparatuses may include a second magnetic conductor integrated within the case and characterized by a thickness that is greater than 30% of the thickness of the case. 
     In some embodiments, the case may be or include a rubber material or plastic between the first surface of the case and the second surface of the case. The electronic device may also include a metal support plate seated proximate the second surface of the electronic device. The metal support plate may include an aperture positioned in line with the first magnetic conductor and the annular wireless charging coil. The first magnetic conductor and the second magnetic conductor may be or include a soft ferrite material or a nanocrystalline foil material. The second magnetic conductor may include a cylindrical post extending for a length of more than 50% of the thickness of the case. The second magnetic conductor may extend from the second surface of the case towards the first surface of the case. The second magnetic conductor may include a cylindrical post and an annular ring extending about the cylindrical post. An annular gap may exist between the cylindrical post and the annular ring of the second magnetic conductor. The second magnetic conductor may extend from the first surface of the case towards the second surface of the case. 
     Some embodiments of the present technology may encompass wireless charging systems. The systems may include a first electronic device. The first electronic device may include a case extending at least partially about the first electronic device. The first electronic device may include a battery housed within the first electronic device. The first electronic device may include a first wireless charging coil housed within the first electronic device. The first electronic device may include a first magnetic conductor housed within the first electronic device and positioned between the battery and the first wireless charging coil. The first wireless charging coil may be seated on the first magnetic conductor. The first electronic device may include a second magnetic conductor integrated within the case proximate the first wireless charging coil and axially aligned with the first magnetic conductor. The systems may include a second electronic device. The second electronic device may include a second wireless charging coil configured to operate in a wireless charging transmission mode. The second electronic device may also include at least one hard magnet within the second electronic device. In some embodiments, the first magnetic conductor and the second magnetic conductor may be or include a soft ferrite material or a nanocrystalline foil material. 
     Such technology may provide numerous benefits over conventional technology. For example, the present systems may produce improved charging efficiency, which may reduce charging times. Additionally, components of the present technology may reduce leakage, which may improve power reception at a device being wirelessly charged. These and other embodiments, along with many of their advantages and features, are described in more detail in conjunction with the below description and attached figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A further understanding of the nature and advantages of the disclosed embodiments may be realized by reference to the remaining portions of the specification and the drawings. 
         FIG.  1    shows a schematic perspective view of an electronic device according to some embodiments of the present technology. 
         FIG.  2    shows a schematic cross-sectional view of an electronic device according to some embodiments of the present technology. 
         FIG.  3    shows a schematic cross-sectional view of a charging system according to some embodiments of the present technology. 
         FIG.  4    shows a schematic cross-sectional view of a charging system according to some embodiments of the present technology. 
         FIGS.  5 A- 5 C  show exemplary component configurations according to some embodiments of the present technology. 
         FIGS.  6 A- 6 B  show coupling and efficiency plots relative to gap size in systems according to some embodiments of the present technology. 
     
    
    
     Several of the figures are included as schematics. It is to be understood that the figures are for illustrative purposes, and are not to be considered of scale unless specifically stated to be of scale. Additionally, as schematics, the figures are provided to aid comprehension and may not include all aspects or information compared to realistic representations, and may include exaggerated material for illustrative purposes. 
     In the figures, similar components and/or features may have the same numerical reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components and/or features. If only the first numerical reference label is used in the specification, the description is applicable to any one of the similar components and/or features having the same first numerical reference label irrespective of the letter suffix. 
     DETAILED DESCRIPTION 
     Wireless charging is a convenient feature for handheld products and smartphones. By incorporating charging coils in transmission and receiver devices, inductive charging can be performed. The process of wireless charging can have challenges including heat generation, regulatory requirements regarding emissions, and charging efficiency, which can all impact performance. For example, during the charging process magnetic flux is emitted from both the transmission coil and the receiver coil. In many systems, ferrite or some magnetic material is utilized to facilitate conduction of the flux to improve efficiency of distribution and collection. The ferrite provides this function by conducting the flux and directing it back towards appropriate coil(s). 
     Additionally, when users seat the electronic device in a case, or when the device may include an enclosure housing the wireless charging components, charging efficiencies may be reduced. For example, a case or device enclosure may increase a gap between a wireless charging coil of a charger and a wireless receiving coil incorporated within the electronic device. For many conventional systems, this reduction may be unavoidable, which may increase current leakage causing more power to be lost during charging, as well as increasing the time to charge the electronic device. The present technology overcomes many of these issues by incorporating a magnetic material into a case or device enclosure to facilitate charging and flux conduction. The material may be characterized by magnetic properties that may reduce leakage as well as the effective gap between the electronic device and the charger. 
     Although the remaining portions of the description will routinely reference smart phones, it will be readily understood by the skilled artisan that the technology is not so limited. The present materials and technology may be employed with any number of electronic devices that may include, without limitation, phones and mobile devices, watches, glasses, and other wearable technology including fitness devices, handheld electronic devices, laptops, tablets, and other computers, as well as other devices that may benefit from the use of wireless charging technology. 
       FIG.  1    shows a schematic perspective view of an electronic device  100  according to some embodiments of the present technology. Electronic device  100  may illustrate a number of devices, which may include a mat, charging station, wireless rechargeable battery, personal computing device, or mobile device, for example. Additionally, electronic device  100  may be a tablet computing device, wearable electronic device, as well as a mobile communication device, such as a smartphone. Electronic device  100  may include an enclosure  102 , or housing, that defines an internal cavity or interior volume to receive several internal components, some of which will be described below, and which may include components such as a circuit board, processor circuit, memory circuit, charging coils, and an internal power supply, as non-limiting examples. The enclosure  102  may include a metal, such as aluminum or steel, or a metal alloy that includes two or more metals. Alternatively, the enclosure  102  may include a non-metal material or materials, such as ceramics, polymers, glass, or other flexible materials including combinations of metal and non-metal materials. 
     The electronic device  100  may further include an active region  104  shown as a dotted line, although in some embodiments region  104  may be a coextensive portion of the enclosure  102 . When present, active region  104  may include a transfer surface, or a display surface designed to present visual information in the form of still images and/or video. The active region  104  may include a capacitive touch sensitive layer designed to receive a touch input to alter the visual information. Also, the electronic device  100  may include a protective cover  106  that overlays the active region  104 , when present. The protective cover  106  may include a transparent material, such as glass or sapphire, as non-limiting examples, and may include EMF shielding materials, or other materials through which electronic transfer may occur. The electronic device  100  may further include a button  108  used as a control input to a processor circuit, not shown. For example, the button  108  may depress in response to a force, and may provide a control that alters the visual information presented by the active region  104 . Additionally, although not shown, the electronic device  100  may include one or more buttons disposed along the enclosure  102  to provide one or more additional control inputs. 
       FIG.  2    shows a simplified schematic cross-sectional view of an electronic device  200  according to some embodiments of the present technology. It is to be understood that electronic device  200  is included merely to illustrate certain components according to some embodiments of the present technology, and is not intended to accurately represent either scale or position of components that may be incorporated in the device. Electronic device  200  may provide an exemplary cross-section of electronic device  100 , where electronic device  100  may include a mobile computing device, or additional devices according to embodiments of the present technology. For example, electronic device  200  may include an enclosure  202  and graphical display assembly  204  as previously described, which may be included on or define a first surface of the electronic device, such as a first exterior surface. Electronic device  200  may additionally be characterized by a second surface  205 , such as a second exterior surface, opposite the first surface at which display assembly  204  may be included. A volume may be defined within enclosure  202  between the first surface and the second surface. Within enclosure  202  may be a number of components as discussed above, and which may include a battery  206 , a graphical processing unit  208 , and an integrated circuit  210 . 
     Battery  206  may be or include a rechargeable battery, including a number of rechargeable battery cell(s). Battery  206  may be a lithium-ion or other secondary battery type, and may be coupled with recharging circuitry and controllers operable to control charging and discharging operations. Integrated circuit  210  may be part of a circuit board, and may be a central processing unit, or other controller that may perform any number of operations within the electronic device, including operations related to wireless charging and discharging. 
     Additionally within enclosure  202  may be a support plate  212  that may include a number of components related to wireless charging. While previously mentioned components may be positioned between the support plate  212  and the graphical display assembly  204 , certain components related to wireless charging may be positioned between or in line with the support plate and the back plate or rear of enclosure  202 , including contacting or at least partially coupled with the rear of enclosure  202 . These components may include a magnetic conductor  214  and a wireless charging coil  216 . 
     First magnetic conductor  214  may be or include a ferrite material or a nanocrystalline foil. The magnetic conductor may be characterized by being non-conductive and ferrimagnetic. Exemplary ferrite materials may include any material including iron, and may include soft ferrites or materials characterized as conductors of magnetic fields. Exemplary materials may include any number of additional elements including nickel, zinc, barium, or manganese, as non-limiting examples. In some embodiments, because many mobile and other electronic devices may be characterized by reduced form factors, ferrite may not provide adequate operational characteristics, as the ferrite may become thinner to accommodate device form factor restrictions. For example, to provide sufficient space for internal components, and more space intensive materials like a battery, which may improve capacity, the ferrite may be reduced to a thickness below a millimeter, or below half a millimeter, or reduced even more. As this reduction occurs, the ability of the ferrite to steer flux continues to degrade, until the ferrite saturates. At this point, it may no longer provide benefits of redirecting fields effectively, and the charging efficiency may continue to degrade. As efficiency drops, the time to charge increases, which may generate even more heat in the device. 
     In many newer devices, an additional issue may be when charging operations occur with devices that may include one or more hard magnets. These hard magnets may be incorporated with drives or other internal components, and may also be included in other aspects, such as for coupling as will be described below. Regardless, hard magnets emit their own flux, which when in close vicinity to the first magnetic conductor, will also be absorbed. This further adds to the flux absorbed by the ferrite, which can quickly reach saturation for the material. Accordingly, in space restrictive devices or any electronic device according to embodiments of the present technology, especially those that may include a hard magnet, ferrite may be removed from the system as a magnetic component, and the devices may use a nanocrystalline foil, which may be or include ferrosilicon-containing material or other magnetic material in a layered or fractured material, and which may include adhesives or other polymer supports within the foil material. The foil may include any number of layers of ferrosilicon-containing material from a single layer, to two layers or more, greater than or about 4 layers, greater than or about 5 layers, greater than or about 6 layers, greater than or about 10 layers, or more. Any other magnetic conducting materials may similarly be incorporated with some embodiments of the present technology. 
     Incorporated with the first magnetic conductor  214  may be a wireless charging coil  216 . When in a receiving operation, wireless charging coil  216  may receive power from a generated electromagnetic field from a transmitting device, and this received power may be converted into current that may charge a rechargeable battery of the electronic device, such as battery  206 . Integrated circuit  210  may be configured to operate the wireless charging coil in a wireless charging receiving mode, such as to provide charging to the battery. In some embodiments, the integrated circuit may also be configured to operate the wireless charging coil in a wireless charging transmission mode. The integrated circuit  210  may operate the coil in either mode by any number of control mechanisms. 
     The wireless charging coil may be a single wire formed in a coil characterized by an annular shape as shown in cross-section in the figure. The annulus may include an inner annular radius  217 , which may be defined from a central axis through the device, and which may define an interior volume or gap through the wireless charging coil. The gap may be characterized by any different geometry depending on the coil distribution, and may be characterized by a cylindrical volume as illustrated. The first magnetic conductor, or a portion of the first magnetic conductor, may extend through the cylindrical volume. An e-shield  218  may be positioned between the wireless charging coil  216  and the back wall of enclosure  202 , and may extend laterally across the wireless charging coil  216  as well as the first magnetic conductor extending through the wireless charging coil. The first magnetic conductor may include multiple layers where a first layer defines a surface on which the wireless charging coil may be seated, and a second layer is positioned within the wireless charging coil centrally defined volume. Each of these layers may also include one or more layers of material. Additionally, the first magnetic conductor may be a single component shaped to the geometry illustrated or any other geometry. The first magnetic conductor may form a recessed ledge on which the wireless charging coil may be seated, and which may be a recessed annular ledge formed to accommodate the coil distribution. 
     The wireless charging coil may be formed of any number of metals or alloys that may be conductive, and may be characterized by a thickness of less than or about 250 μm in some embodiments, which may limit the use of space within device  200 . Additionally, in some embodiments the wireless charging coil may be characterized by a thickness of less than or about 200 μm, less than or about 150 μm, less than or about 100 μm, less than or about 50 μm, or less. The thickness of the coil may be one of several competing factors that may be used to accommodate the form factor of electronic device  200 . For example, increasing the thickness of coil  216  may then increase the thickness of the associated magnetic material, which may reduce space available for a battery. Additionally, reducing the thickness of the coil may provide more space within the housing, but may increase the resistance of the coil, which may increase heating during charging operations. Accordingly, in some embodiments the wireless charging coil may be characterized by a thickness greater than or about 20 μm, greater than or about 30 μm, greater than or about 40 μm, greater than or about 50 μm, greater than or about 60 μm, greater than or about 70 μm, or more. Another advantage of utilizing a nanocrystalline foil according to some embodiments of the present technology is that the foil may be characterized by a reduced thickness relative to ferrite, which may allow an increased coil thickness, while maintaining a similar or reduced overall form factor. 
       FIG.  3    shows a schematic cross-sectional view of a charging system  300  according to some embodiments of the present technology. The charging system is illustrated with an electronic device, which may include any component or aspect of electronic device  200  discussed above, although  FIG.  3    is illustrated with only some components, such as certain components related to wireless charging. It is to be understood, however, that the description may similarly relate to or include any other device discussed throughout the present disclosure. As illustrated, system  300  may include a first electronic device  305  shown in a simplified form, but which may be similar to any of the electronic devices previously described, including a phone, tablet, or other device, and may include any of the components of electronic devices  100  or  200 , including being electronic devices  100  or  200 , and may include any of the material characteristics previously described. As previously discussed, first electronic device  305  may include a battery  307  and an integrated circuit as noted in electronic device  200 . The integrated circuit may be configured to operate the first wireless charging coil in a receiving mode or transmission mode in embodiments. 
     First electronic device  305  may include a wireless charging coil  310 , which may be positioned near or proximate a second surface  312  of the electronic device, such as opposite a display as noted previously. Second surface  312  may be any material forming the electronic device, such as glass, plastic, metal, or any other materials that may be used in an enclosure of an electronic device as discussed above. The wireless charging coil  310  may be disposed within an interior volume of the first electronic device. A first magnetic conductor  315  may be housed within the interior volume as well, and may be positioned between the battery  307  and the wireless charging coil. An optional e-shield  318  may additionally be included in some embodiments. 
     As illustrated, the first magnetic conductor  315  may define a recessed annular ledge about the conductor in some embodiments, and with or without the ledge, wireless charging coil  310  may be seated on the first magnetic conductor  315 . In some embodiments an e-shield may be positioned within the interior volume of the first electronic device between the wireless charging coil and the second surface of the first electronic device. A support plate  320  may be seated against or proximate an internal surface of the second surface of the first electronic device. Support plate  320  may be metal or any other material, and may provide additional stability and strength for the device. In some embodiments where support plate  320  is metal, an aperture  322  or access may be defined through the support plate. The aperture  322  may be sized and positioned in line with the first magnetic conductor  315  and the wireless charging coil  310 , to ensure wireless power may be received or transmitted through the device. 
     Additionally illustrated is an electronic device case  325 , which may at least partially extend about the electronic device  305  to provide an electronic apparatus. Although the remaining materials will reference device cases, it is to be understood that the present technology may similarly apply to thicker electronic devices, such as for which the identified material  325  may also encompass an enclosure of device  305 , which may not be a separable case, and may be actual device enclosure components. Many users of electronic devices use cases to provide additional support and protection for the electronic device, as well as functionality, such as charging, built-in stands, foldable covers providing additional storage, and other common aspects of device cases. Case  325  may provide apertures through the structure, such as for camera lenses, lights, buttons, switches, connection ports, speakers, microphones, and other aspects of the device. However, case  325  may generally extend across second surface  312  of the first electronic device  305 , and may further extend along side surfaces, and may or may not extend across a top face, first surface, or display of the electronic device. Case  325  may be or include a single component, or multiple separate and joinable components in embodiments. Case  325  may include a first surface  327  contacting the second surface  312  of the electronic device. Case  325  may additionally include a second surface  329  of the case, which may be opposite the first surface  327 . Case  325  may be characterized by a thickness between the first surface  327  and the second surface  329  of the case. The thickness may be consistent or inconsistent across the case. Case  325  may be made of any number of materials that may be or include plastic, metal, rubber, glass, polymeric materials, or any other materials that may be used to produce electronic device cases. 
     Charging system  300  may also include a second electronic device  350 , which may be a wireless charger in some embodiments. Wireless chargers compatible with the present technology may include any number of devices, including any device noted above in  FIG.  1    and  FIG.  2   . Although the wireless chargers may or may not include wired power coupling, second electronic device  350  may optionally include a wired connection  355  for access to mains power. Second electronic device  350  may include any number of components, but of note may include a second wireless charging coil  360 , which may include any of the features, materials, or characteristics of wireless charging coils described previously. Second electronic device  350  may include a ferrite, foil, or other magnetic conductor  365 . Additionally, second electronic device  350  may include one or more hard magnets  370 , which may allow coupling with a first electronic device to facilitate wireless charging and coil alignment. As explained above, hard magnets in these electronic devices may cause additional magnetic flux, which may be absorbed by the magnetic conductors, although the additional magnetic flux may impact efficiency of charging and saturation of the materials. In some embodiments, nanocrystalline foils may afford increased saturation relative to some ferrite materials, which may maintain charging operations at higher efficiency. 
     Wireless charging efficiency may be impacted by a number of factors including materials used, power levels, as well as a distance or gap between the wireless charging coils of the transmitting and receiving devices. Even small increases in gap distance may impact the efficiency of charging, which may be directly related to a coupling coefficient that is affected by gap distance. For example, when a first electronic device to be charged is placed directly on a second electronic device transmitting wireless power, the gap may be minimal between the two components, and may be affected only by enclosure materials covering the coils of the two devices. However, when an electronic device is seated within a case, such as case  325 , the gap between the coils may increase. For example, for an exemplary first and second electronic device, direct coupling may produce a coupling coefficient of about 0.9, which accounts for the exterior housing of the two devices. When a case is inserted to increase the gap by even 2 mm, or a thicker device enclosure is used, the coupling coefficient may drop to 0.7 or lower. If the case or enclosure increases the gap to 4 mm, the coupling coefficient may further reduce to 0.5 or lower, which may be dependent on the devices, materials of the case, and other environmental factors. Regardless, this reduction may dramatically increase the leakage of magnetic flux, which reduces charging efficiency. This may both produce higher power loss or waste, and may increase the time to charge the first electronic device. 
     The present technology may recover a portion if not a majority of these losses by incorporating a second magnetic conductor within the case material.  FIG.  4    shows a schematic cross-sectional view of a charging system  400  according to some embodiments of the present technology. Charging system  400  may include similar components as charging system  300 , but may incorporate a different case for the electronic device. Charging system  400  may include a first electronic device  305  and a second electronic device  350 , which may include any of the components, materials, or characteristics of any device discussed previously. However, in some embodiments, first electronic device  305  may be seated within a case  425 , which may also be illustrative of an adapted enclosure that extends a similar amount about the internal components. Case  425 , or an integrated enclosure, may have any of the components, characteristics, or materials of case  325  or any other case discussed above, including a device enclosure of similar proportions. For example, case  425  may extend about electronic device  305 , and contact second surface  312  of first electronic device  305  along a first surface  427  of case  425 . Case  425  may also be characterized by a second surface  429  opposite first surface  427 . A thickness of the case  425  may be defined between the first surface  427  and the second surface  429  of the case as described above. 
     Case  425  may also include a second magnetic conductor  450  incorporated or integrated within the case  425  along or through a thickness of the case. Second magnetic conductor  450  may coordinate with first magnetic conductor  315  of electronic device  305  to facilitate wireless power delivery and improve efficiency of charging of the electronic device. Second magnetic conductor  450  may be the same material or a different material from first magnetic conductor  450 , and may be or include any of the materials described previously, including ferrite materials, such as soft ferrite materials, nanocrystalline foil materials, or other magnetic conductor materials. 
     The second magnetic conductor may include one or more features to accommodate aspects of the wireless charging coil  310  and first magnetic conductor  315 . For example, as discussed above, wireless charging coil  310  may be characterized by an annular shape, which may be further characterized as having a radial length from an inner annular radius of the wireless charging coil to an outer annular radius of the wireless charging coil along a radius of the charging coil extending from a central axis through the wireless charging coil. First magnetic conductor  315  may include one or more components including a central post  416  extending through the wireless charging coil and a sheet  417  extending along a surface of the wireless charging coil as illustrated. Second magnetic conductor  450  may include one or more components that accommodate this structure. For example, second magnetic conductor may include a geometrically shaped post, such as a cylindrical post  455 , extending at least partially within and through the case  425 , and which may be axially aligned with central post  416  of the first magnetic conductor. Second magnetic conductor may also include an annular ring  460  extending about the cylindrical post  455 , and which may be axially aligned with the sheet  417 , wireless charging coil  310 , or other feature of the wireless charging components of the electronic device  305 . It is also to be understood that electronic device  305  need not include complementary magnetic structures adjacent to magnetic conductor  450 . 
     An annular gap  465  may exist between the cylindrical post  455  and the annular ring  460  as illustrated. In some embodiments, the radial length of the wireless charging coil may be less than or about a radial length of the annular gap  465  of the second magnetic conductor, which may maintain the charging coil exposed to the transmitting or receiving charging coil of an associated second electronic device. Second magnetic conductor  450  may be characterized by a number of varying components and configurations, and is not intended to be limited by the example illustrated in  FIG.  4   . For example, second magnetic conductors according to embodiments of the present technology may include either of the noted components as well as variations on the locations and thicknesses of the materials. 
       FIGS.  5 A- 5 C  show exemplary component configurations according to some embodiments of the present technology. For example,  FIGS.  5 A- 5 C  show a few illustrative possibilities for second magnetic conductor configurations. It is to be understood that the figures are not intended to be limiting, but are included to describe some of the adjustments that may be performed or applied to cases according to embodiments of the present technology. Cases illustrated in  FIGS.  5 A- 5 C  may include any of the materials, components, or characteristics described elsewhere. 
       FIG.  5 A  illustrates an example incorporation of a second magnetic conductor  510  where only a central post is utilized. Additionally, the central post is included through only a partial thickness of the case  505  from a second surface  507  towards a first surface  506 . In another embodiment the central post may extend partially through the case from first surface  506  towards second surface  507 . The amount of extension within or through the thickness of the case may be beneficial to charging efficiency regardless of the amount of inclusion by reducing an effective gap between the two charging coils of a wireless charging system. The second magnetic conductor may further direct or channel magnetic flux towards the receiving coil by extending the magnetic field through the conductive material of the second magnetic conductor. 
     Accordingly, while incorporating magnetic conductor material fully through the case may produce the most improvement, any incorporation may improve the coupling coefficient by reducing an effective gap distance between the coils. Hence, in embodiments of the present technology, any component of the second magnetic conductor may extend at least about 10% of a distance or thickness through or within a case, and any component may extend greater than or about 20% of the distance or thickness through the case, greater than or about 30%, greater than or about 40%, greater than or about 50%, greater than or about 60%, greater than or about 70%, greater than or about 80%, greater than or about 90%, greater than or about 95%, greater than or about 98%, or more, although in some embodiments the second magnetic conductor may be fully integrated or incorporated within the case or enclosure, and may not extend through a top or bottom surface of the case. 
       FIG.  5 B  illustrates another exemplary embodiment where second magnetic conductor  520  includes only an annular ring extending through the case  515 . In some embodiments, annular ring  520  may or may not be a complete ring as well. For example, a series of posts may be incorporated in an arcuate pattern about the case, or semicircular sections of second magnetic conductor material may be included. Additionally, the annular ring may extend any amount within the case as noted above.  FIG.  5 C  illustrates yet another example of a second magnetic conductor  530  incorporated within case  525 . As illustrated, second magnetic conductor  530  includes several of the variations noted above, and also shows an additional variation where multiple of the components of the conductor may be included. For example, along with central post  535  extending partially through the case material, a first annular ring  540  may be included proximate a first surface  526  of case  525 , and a second annular ring  545  may be included proximate a second surface  527  of case  525 . Each of the annular rings may extend any distance through the case, and may also be laterally offset from one another, although the rings may be concentric about central post  535 . Accordingly, any number of variations for incorporating a second magnetic conductor in a case may be performed and are similarly encompassed by the present technology. 
       FIGS.  6 A- 6 B  show coupling and efficiency plots relative to gap size in systems according to some embodiments of the present technology. For example,  FIG.  6 A  illustrates an effect on coupling between wireless charging coils, and the efficiency of charging, as a gap between a transmitting and a receiving coil is increased with a case or thicker enclosure as explained previously, such as with  FIG.  3   , for example. As the case thickness increases, the gap between the coils increases, and coupling between the coils reduces exponentially. This creates an exponential reduction in charging efficiency, which may increase power losses and increase charging time.  FIG.  6 B  illustrates an effect on coupling for the same system, but with a case or enclosure according to embodiments according to the present technology including a second magnetic conductor material incorporated in the case. 
     As illustrated, a similar gap length increase only marginally reduces coupling between the coils as well as charging efficiency. Consequently, cases or device enclosures incorporating second magnetic conductor materials according to embodiments of the present technology may maintain up to or greater than about 75% efficiency and/or coupling despite an increase in gap length relative to directly coupled devices, and may maintain greater than or about 80% efficiency and/or coupling, greater than or about 85% efficiency and/or coupling, greater than or about 90% efficiency and/or coupling, greater than or about 95% efficiency and/or coupling, greater than or about 98% efficiency and/or coupling, or more. By using second magnetic conductors according to embodiments of the present technology, either within electronic devices having thicker enclosures, or in cases in which electronic devices may be seated, efficiency and coupling may be at least partially maintained to limit power losses and increases in charging time. 
     In the preceding description, for the purposes of explanation, numerous details have been set forth in order to provide an understanding of various embodiments of the present technology. It will be apparent to one skilled in the art, however, that certain embodiments may be practiced without some of these details, or with additional details. 
     Having disclosed several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the embodiments. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present technology. Accordingly, the above description should not be taken as limiting the scope of the technology. 
     Where a range of values is provided, it is understood that each intervening value, to the smallest fraction of the unit of the lower limit, unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Any narrower range between any stated values or unstated intervening values in a stated range and any other stated or intervening value in that stated range is encompassed. The upper and lower limits of those smaller ranges may independently be included or excluded in the range, and each range where either, neither, or both limits are included in the smaller ranges is also encompassed within the technology, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included. Where multiple values are provided in a list, any range encompassing or based on any of those values is similarly specifically disclosed. 
     As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, reference to “a material” includes a plurality of such materials, and reference to “the layer” includes reference to one or more layers and equivalents thereof known to those skilled in the art, and so forth. 
     Also, the words “comprise(s)”, “comprising”, “contain(s)”, “containing”, “include(s)”, and “including”, when used in this specification and in the following claims, are intended to specify the presence of stated features, integers, components, or operations, but they do not preclude the presence or addition of one or more other features, integers, components, operations, acts, or groups.

Metadata:
Filing Date: 20200807
Publication Date: 20241119
Grant Date: 20241119
Priority Date: 20190812
Inventors: QIU, WEIHONG
LIU, JUN
MOUSSAOUI, ZAKI
Assignee: APPLE INC
CPC Classifications: [{"code": "H02J7/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F38/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F5/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/90", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F38/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/0042", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J50/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F7/0247", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F2003/103", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F27/366", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/0042", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/70", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02J50/005", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01F38/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02J50/005", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02J50/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J7/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F38/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 74239940