Wireless power transfer

• US 10,186,904 B2
• Filed: 12/28/2015
• Issued: 01/22/2019
• Est. Priority Date: 01/17/2012
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Muratov, Vladimir A., Rice, John C.
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Vu, Toan
• Application Number:
  US14/980,212
• Publication Number:
  US 20160226310A1
• Time in Patent Office: 1,121 Days
• Field of Search: 307104
• CPC Class Codes: H01F 2027/348 Preventing eddy currents
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/363 made of electrically conductive material
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• 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 50/90 involving detection or optimisation of position, e.g. alignment

Abstract

A wireless power transmitter can include a transmitting coil configured to wirelessly transmit power to a receiving coil. The wireless power transmitter can include a shield residing on a given side of a substrate spaced apart from the transmitting coil. The shield can be configured to filter an electric field induced by the transmitting coil.

Claims

1. A wireless power transmitter comprising:

a source;

a transmission coil coupled to the source; and

a shield positioned adjacent to the transmission coil, the shield including;

a substrate having a first side and a second side opposite the first side;

a first conductive layer on the first side of the substrate, the first conductive layer having a first base, and first traces spaced apart from each other, each one of the first traces having a first end extended from the first base, and a second end distal from the first base; and

a second conductive layer on the second side of the substrate, the second conductive layer having a second base, and second traces spaced apart from each other, each one of the second traces having a third end extended from the second base, and a fourth end distal from the second base, the second traces interleaving the first traces along a plane defined by the substrate.

2. The wireless power transmitter of claim 1, wherein:

the first traces coextend with each other and are spaced apart from each other by a first space;

the second traces coextend with each other and are spaced apart from each other by a second space;

the first space overlaps with the second traces; and

the second space overlaps with the first traces.

3. The wireless power transmitter of claim 1, wherein the first base overlaps the second base.

4. The wireless power transmitter of claim 1, wherein each of the first and second traces is curved.

5. The wireless power transmitter of claim 1, further comprising:

a second shield positioned between the transmission coil and the source, the second shield comprising a disc of ferrite,

wherein the shield is a first shield and the transmission coil is positioned between the first shield and the second shield.

6. The wireless power transmitter of claim 5, further comprising:

a third shield housing the source and the transmission coil, and defining an opening to expose a footprint of the transmission coil.

7. The wireless power transmitter of claim 1, wherein the shield is positioned between the transmission coil and a reception coil of a wireless power receiver.

8. The wireless power transmitter of claim 1, wherein shield is positioned between the transmission coil and the source.

9. A wireless power receiver comprising:

a load;

a reception coil coupled to the load; and

a shield positioned adjacent to the reception coil, the shield including;

a substrate having a first side and a second side opposite the first side;

a first conductive layer on the first side of the substrate, the first conductive layer having a first base, and first traces spaced apart from each other, each one of the first traces having a first end extended from the first base, and a second end distal from the first base; and

a second conductive layer on the second side of the substrate, the second conductive layer having a second base, and second traces spaced apart from each other, each one of the second traces having a third end extended from the second base, and a fourth end distal from the second base, the second traces interleaving the first traces along a plane defined by the substrate.

10. The wireless power receiver of claim 9, wherein:

the first traces coextend with each other and are spaced apart from each other by a first space;

the second traces coextend with each other and are spaced apart from each other by a second space;

the first space overlaps with the second traces; and

the second space overlaps with the first traces.

11. The wireless power receiver of claim 9, wherein the first base overlaps the second base.

12. The wireless power receiver of claim 9, wherein each of the first and second traces is curved.

13. The wireless power receiver of claim 9, further comprising:

a second shield positioned between the reception coil and the load, the second shield comprising a disc of ferrite,

wherein the shield is a first shield and the reception coil is positioned between the first shield and the second shield.

14. The wireless power receiver of claim 13, further comprising:

a third shield housing the source and the transmission coil, and defining an opening to expose a footprint of the transmission coil.

15. The wireless power receiver of claim 9, wherein the shield is positioned between the reception coil and a transmission coil of a wireless power transmitter.

16. The wireless power receiver of claim 9, wherein shield is positioned between the reception coil and the load.

17. A shield for use in a wireless power transfer system, the shield comprising:

a substrate adapted for placement adjacent to a transmission coil or a reception coil, the substrate having a first side and a second side opposite the first side;

a first conductive layer on the first side of the substrate, the first conductive layer having a first base, and first traces spaced apart from each other, each one of the first traces having a first end extended from the first base, and a second end distal from the first base; and

a second conductive layer on the second side of the substrate, the second conductive layer having a second base, and second traces spaced apart from each other, each one of the second traces having a third end extended from the second base, and a fourth end distal from the second base, the second traces interleaving the first traces along a plane defined by the substrate.

18. The shield of claim 17, wherein:

the first traces coextend with each other and are spaced apart from each other by a first space;

the second traces coextend with each other and are spaced apart from each other by a second space;

the first space overlaps with the second traces; and

the second space overlaps with the first traces.

19. The shield of claim 17, wherein the first base overlaps the second base.

20. The shield of claim 17, wherein each of the first and second traces is curved.