POWER FEEDING APPARATUS, POWER RECEIVING APPARATUS, WIRELESS POWER FEEDING SYSTEM AND METHOD FOR WIRELESS TRANSFER OF POWER

• US 20110248572A1
• Filed: 04/05/2011
• Published: 10/13/2011
• Est. Priority Date: 04/09/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Miyamoto, Takashi, Murayama, Yuji, Kozakai, Osamu
• Granted Patent: US 9,006,934 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H03F 1/565 using inductive elements

Abstract

A power feeding apparatus, power receiving apparatus, wireless power feeding system, and method for wireless transfer of power are provided. The power feeding apparatus includes an impedance detector, a controller, a power transmitter, a variable matching circuit, and a signal transmitter. The controller is configured to provide first control information and second control information based on an impedance detected by the impedance detector. The power feeding apparatus'"'"' variable matching circuit is configured to change a variable diameter of a power feeding coil according to the first control information. The power receiving apparatus includes a power receiver, a signal receiver, and a variable matching circuit. The power receiving apparatus'"'"' variable matching circuit is configured to change a variable diameter of a power feeding coil according to the second control information provided by the power feeding apparatus.

Claims

1. A power feeding apparatus comprising:

an impedance detector;

a controller configured to provide first control information and second control information based on an impedance detected by the impedance detector;

a power transmitter configured to wirelessly transmit power, the power transmitter including a power feeding coil with a variable diameter;

a variable matching circuit configured to change the variable diameter of the power feeding coil according to the first control information; and

a signal transmitter configured to wirelessly transmit the second control information.

2. The power feeding apparatus of claim 1, wherein the first control information is based on a current state of the variable matching circuit and the impedance detected by the impedance detector.

3. The power feeding apparatus of claim 1, wherein the second control information is based on an external current state of an external variable matching circuit, associated with an external device, and an external impedance of the external device.

4. The power feeding apparatus of claim 3, wherein the signal transmitter is configured to receive information from the external device including the external current state.

5. The power feeding apparatus of claim 3, further comprising:

a storage device configured to store impedance characteristic information including a relationship between an impedance characteristic of the power feeding apparatus and an external impedance characteristic of the external device.

6. The power feeding apparatus of claim 5, wherein the controller is configured to estimate the external impedance based on the impedance characteristic information and the impedance detected by the impedance detector.

7. The power feeding apparatus of claim 1, wherein the second control information includes at least one of diameter change information, impedance detection result information, and setting information associated with an external variable matching circuit.

8. A power receiving apparatus comprising:

a power receiver configured to wirelessly receive power, the power receiver including a power feeding coil with a variable diameter;

a signal receiver configured to wirelessly receive control information, wherein the control information is based on an impedance detected in an external device; and

a variable matching circuit configured to change the variable diameter of the power feeding coil according to the control information.

9. The power receiving apparatus of claim 8, wherein the variable matching circuit changes the variable diameter of the power feeding coil independent of detecting an impedance in the power receiving apparatus.

10. The power receiving apparatus of claim 8, wherein the signal receiver is configured to transmit information to the external device including a current state of the variable matching circuit.

11. The power receiving apparatus of claim 8, wherein the control information includes at least one of diameter change information, impedance detection result information, and setting information associated with the variable matching circuit.

12. A wireless power feeding system comprising:

a power feeding apparatus and a power receiving apparatus,

the power feeding apparatus including;

(a) an impedance detector;

(b) a controller configured to provide first control information and second control information based on an impedance detected by the impedance detector;

(c) a power transmitter configured to wirelessly transmit power to the power receiving apparatus, the power transmitter including a first power feeding coil with a first variable diameter;

(d) a first variable matching circuit configured to change the first variable diameter of the first power feeding coil according to the first control information; and

(e) a signal transmitter configured to wirelessly transmit the second control information to the power receiving apparatus; and

the power receiving apparatus including;

(a) a power receiver configured to wirelessly receive power from the power feeding apparatus, the power receiver including a second power feeding coil with a second variable diameter;

(b) a signal receiver configured to wirelessly receive the second control information from the power feeding apparatus; and

(c) a second variable matching circuit configured to change the second variable diameter of the second power feeding coil according to the second control information, wherein the second control information is based on the impedance detected in the power feeding apparatus.

13. The wireless power feeding system of claim 12, wherein the first control information is based on a current state of the first variable matching circuit and the impedance detected by the impedance detector.

14. The wireless power feeding system of claim 12, wherein the second control information is based on a current state of the second variable matching circuit and an impedance of the power receiving apparatus.

15. The wireless power feeding system of claim 14, wherein the signal transmitter is configured to receive information from the power receiving apparatus including the current state of the second variable matching circuit.

16. The wireless power feeding system of claim 14, wherein the power feeding apparatus includes:

a storage device configured to store impedance characteristic information including a relationship between an first impedance characteristic of the power feeding apparatus and a second impedance characteristic of the power receiving apparatus.

17. The wireless power feeding system of claim 16, wherein the controller is configured to estimate the impedance of the power receiving apparatus based on the impedance characteristic information and the impedance detected by the impedance detector.

18. The wireless power feeding system of claim 12, wherein the second control information includes at least one of diameter change information, impedance detection result information, and setting information associated with the second variable matching circuit.

19. The wireless power feeding system of claim 12, wherein the second variable matching circuit changes the second variable diameter of the second power feeding coil independent of detecting an impedance in the power receiving apparatus.

20. A method for a wireless transfer of power from a power feeding apparatus to a power receiving apparatus, the method comprising:

detecting an impedance in the power feeding apparatus;

controlling transmission of power in the power feeding apparatus based on the impedance detected in the power feeding apparatus; and

controlling reception of power in the power receiving apparatus based on the impedance detected in the power feeding apparatus.

21. The method of claim 20, wherein controlling transmission of power in the power feeding apparatus is based on a current state of a variable matching circuit in the power feeding apparatus and the impedance detected in the power feeding apparatus.

22. The method of claim 20, wherein controlling reception of power in the power receiving apparatus is based on a current state of a variable matching circuit in the power receiving apparatus and an impedance of the power receiving apparatus.

23. The method of claim 22, further comprising:

wirelessly transmitting information from the power receiving apparatus to the power feeding apparatus, the information including the current state of the variable matching circuit in the power receiving apparatus.

24. The method of claim 22, further comprising:

storing impedance characteristic information in the power feeding apparatus, the impedance characteristic information including a relationship between a first impedance characteristic of the power feeding apparatus and a second impedance characteristic of the power receiving apparatus.

25. The method of claim 24, further comprising:

estimating the impedance of the power receiving apparatus based on the impedance characteristic information and the impedance detected in the power feeding apparatus.

26. The method of claim 20, further comprising:

wirelessly transmitting control information from the power feeding apparatus to the power receiving apparatus, the control information including at least one of diameter change information, impedance detection result information, and setting information associated with a variable matching circuit in the power receiving apparatus.

27. The method of claim 20, wherein controlling reception of power in the power receiving apparatus is independent of detecting an impedance in the power receiving apparatus.