APPARATUS AND METHODS FOR SHIELDING A WIRELESS POWER TRANSMITTER

• US 20170085134A1
• Filed: 05/16/2016
• Published: 03/23/2017
• Est. Priority Date: 09/17/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: JEONG, Seong Heon
• Granted Patent: US 10,181,757 B2
• Time in Patent Office: Days
• CPC Class Codes: H01F 27/361 made of combinations of electrically conductive material and ferromagnetic material
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H04B 15/02 Reducing interference from electric apparatus by means located at or near the interfering apparatus
• CPC Class Codes: H05K 1/0227 Split or nearly split shielding or ground planes
• CPC Class Codes: H05K 1/0239 Signal transmission by AC coupling
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/09672 Superposed layout, i.e. in different planes parallel traces in one plane H05K2201/09236
• CPC Class Codes: H05K 9/0081 Electromagnetic shielding materials, e.g. EMI, RFI shielding H05K9/0003 takes precedence

Abstract

Methods and apparatus are disclosed for wirelessly transmitting power. In one aspect, an apparatus for wireless transmitting power is provided. The apparatus comprises a first metal sheet having a shape that defines a plurality of slots, the plurality of slots inwardly extending from a periphery of the first metal sheet. The apparatus further comprises a coil configured to generate a magnetic field sufficient to charge or power a load, wherein the first metal sheet extends over a width and a length of the coil, and wherein the plurality of slots are configured to at least partially cancel eddy currents generated in the first metal sheet via the magnetic field.

Claims

1. An apparatus for wirelessly transmitting power, the apparatus comprising:

a first metal sheet having a shape that defines a plurality of slots, the plurality of slots inwardly extending from a periphery of the first metal sheet; and

a coil configured to generate a magnetic field sufficient to charge or power a load, wherein the first metal sheet extends over a width and a length of the coil and wherein the plurality of slots are configured to at least partially cancel eddy currents generated in the first metal sheet via the magnetic field.

2. The apparatus of claim 1, further comprising one or more ferrite pieces.

3. The apparatus of claim 2, wherein the one or more ferrite are pieces placed over or within the plurality of slots.

4. The apparatus of claim 1, further comprising a second metal sheet, wherein the first metal sheet is located on a first side of the coil and the second metal sheet is located on a second side of the coil.

5. The apparatus of claim 4, wherein the second metal sheet comprises a full metal sheet.

6. The apparatus of claim 1, wherein the coil comprises a coil loop along a first plane, wherein the plurality of slots overlap at least a portion of the coil loop and are configured perpendicular to the coil loop along the first plane.

7. The apparatus of claim 1, further comprising a dielectric sheet located on a first side of the first metal sheet.

8. The apparatus of claim 1, wherein the first metal sheet is located on a first side of the coil.

9. The apparatus of claim 1, further comprising a third metal sheet, the third metal sheet comprising a plurality of slots, the plurality of slots extending from a periphery of the third metal sheet, wherein the first metal sheet is located on a first side of the coil and the third metal sheet is located on a second side of the coil.

10. The apparatus of claim 1, wherein the first metal sheet is configured to shield the coil from a metal or foreign object or surface located within a charging region of the coil.

11. The apparatus of claim 1, further comprising a resonant circuit comprising the coil.

12. The apparatus of claim 1, wherein the plurality of slots extend horizontally inwardly from opposite sides of the first metal sheet, and wherein pairs of slots from opposite sides of the first metal sheet overlap vertically within a center region of the first metal sheet.

13. The apparatus of claim 1, wherein the plurality of slots extend diagonally across the first metal sheet.

14. The apparatus of claim 1, wherein the plurality of slots comprise a first group of slots oriented in a first direction, and a second group of slots oriented in a second direction perpendicular to the first direction.

15. A method of shielding a wireless power transmitter, comprising:

positioning a first metal sheet comprising a plurality of slots relative to a coil, such that the first metal sheet extends over a width and a length of the coil, the plurality of slots inwardly extending from a periphery of the first metal sheet,

wherein the coil is configured to generate a magnetic field sufficient to charge or power a load, and

wherein the plurality of slots are configured to at least partially cancel eddy currents generated in the first metal sheet via the magnetic field.

16. The method of claim 15, further comprising positioning one or more ferrite pieces over or within the plurality of slots.

17. The method of claim 15, further comprising positioning a second metal sheet, wherein the first metal sheet is located on a first side of the coil and the second metal sheet is located on a second side of the coil.

18. The method of claim 15, wherein the coil comprises a coil loop along a first plane, wherein the plurality of slots overlap at least a portion of the coil loop and are configured perpendicular to the coil loop along the first plane.

19. The method of claim 15, wherein the coil comprises a resonant circuit.

20. An apparatus for wirelessly transmitting power, the apparatus comprising:

means for generating a magnetic field sufficient to charge or power a load; and

means for shielding the generating means, wherein the shielding means is configured to at least partially cancel eddy currents generated in the means for shielding via the magnetic field.

21. The apparatus of claim 20, wherein the shielding means comprises one or more ferrite pieces positioned over or within a plurality of slots.

22. The apparatus of claim 20, further comprising second means for shielding the generating means, wherein the means for shielding is located on a first side of the generating means and the second means for shielding is located on a second side of the generating means.

23. The apparatus of claim 20, wherein the generating means comprises a coil loop along a first plane, wherein the shielding means comprises a plurality of slots overlapping at least a portion of the coil loop and configured to be perpendicular to the coil loop along the first plane.

24. The apparatus of claim 20, wherein the generating means comprises a resonant circuit.

25. An apparatus for wirelessly transmitting power, the apparatus comprising:

a first metal sheet having a shape that defines a plurality of slots; and

a coil configured to generate a magnetic field sufficient to charge or power a load, wherein the first metal sheet extends over a width and a length of the coil, wherein the coil comprises a coil loop along a first plane, wherein the plurality of slots overlap at least a portion of the coil loop wherein the plurality of slots are configured to at least partially cancel eddy currents generated in the first metal sheet via the magnetic field.

26. The apparatus of claim 25, comprising one or more ferrite pieces placed over or within the plurality of slots.

27. The apparatus of claim 25, further comprising a second metal sheet, wherein the first metal sheet is located on a first side of the coil and the second metal sheet is located on a second side of the coil.

28. The apparatus of claim 25, wherein the plurality of slots are configured to be perpendicular to the coil loop along the first plane.

29. The apparatus of claim 25, wherein the first metal sheet is configured to shield the coil from a metal or foreign object or surface located within a charging region of the coil.

30. The apparatus of claim 25, further comprising a resonant circuit comprising the coil.