Power feeding device, power feeding method, and power feeding system

• US 20120091989A1
• Filed: 09/16/2011
• Published: 04/19/2012
• Est. Priority Date: 10/15/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Uramoto, Yoichi, Tanaka, Masayuki
• Granted Patent: US 9,831,704 B2
• Time in Patent Office: Days
• US Class Current: 324/76.11
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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: H02J 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection

Abstract

Disclosed herein is a power feeding device including: power transmitting section which transmits electric power by way of a magnetic field; a set of first and second electrodes which are spaced from each other; a power supply which applies a voltage between the first and second electrodes; and a detector which detects whether foreign matter is present on the power transmitting section or not based on the voltage applied by the power supply.

Claims

1. A power feeding device comprising:

a power transmitting section which transmits electric power by way of a magnetic field;

a set of first and second electrodes which are spaced from each other;

a power supply which applies a voltage between said first and second electrodes; and

a detector which detects whether foreign matter is present on said power transmitting section or not based on the voltage applied by said power supply.

2. The power feeding device according to claim 1, including a plurality of sets of first and second electrodes which are spaced from each other.

3. The power feeding device according to claim 2, wherein each of said first and second electrodes is of a linear shape, and said first and second electrodes are alternately disposed at spaced intervals.

4. The power feeding device according to claim 2, wherein each of said first and second electrodes is of a dot shape, and said first and second electrodes are alternately disposed at spaced intervals.

5. The power feeding device according to claim 1, wherein each of said first and second electrodes comprises a combtoothed electrode, and said first and second electrodes are arranged in an interdigitating pattern and spaced out of contact with each other.

6. The power feeding device according to claim 1, wherein said power transmitting section comprises:

a coil;

a circuit board, said detector being included in said circuit board; and

a magnetic layer disposed between said circuit board and said coil.

7. The power feeding device according to claim 6, wherein each of said first and second electrodes extends through at least a portion of said magnetic layer from said coil toward said circuit board.

8. The power feeding device according to claim 1, wherein said voltage applied between said first and second electrodes by said power supply comprises an AC voltage.

9. The power feeding device according to claim 1, wherein said detector detects whether foreign matter is present on said power transmitting section or not based on a change in a parameter which is represented by at least one of an impedance, a current, and a voltage between said first and second electrodes.

10. The power feeding device according to claim 9, wherein said detector detects whether foreign matter is present on said power transmitting section or not based on the magnitudes of a change in the parameter from a value thereof at the time no object is placed on said power transmitting section and a predetermined first threshold value.

11. The power feeding device according to claim 10, wherein

said voltage applied between said first and second electrodes by said power supply comprises an AC voltage, and

said detector detects whether foreign matter is present on said power transmitting section or not based on the magnitudes of a change in the parameter and a predetermined second threshold value which is different from said predetermined first threshold value.

12. The power feeding device according to claim 1, wherein said detector comprises:

an AC signal source; and

an inductor and a capacitor which are connected to said AC signal source.

13. The power feeding device according to claim 12, wherein said capacitor is connected between said first and second electrodes.

14. The power feeding device according to claim 12, wherein said detector detects whether foreign matter is present on said power transmitting section or not, with a resonant circuit which includes said inductor and said capacitor.

15. The power feeding device according to claim 1, wherein said detector detects whether foreign matter is present on said power transmitting section or not, using an AC signal having a frequency which is different from the frequency of the electric power transmitted by said power transmitting section.

16. The power feeding device according to claim 1, further comprising:

a control circuit which, if said detector detects when foreign matter is present on said power transmitting section, controls said power transmitting section to stop transmitting the electric power or reduce the electric power to be transmitted, or indicates the detection of the foreign matter to a user of the power feeding device.

17. A power feeding method comprising:

transmitting electric power from a power transmitting section by way of a magnetic field; and

applying a voltage between at least a set of first and second electrodes which are spaced from each other, to detect whether foreign matter is present on said power transmitting section or not.

18. A power feeding system comprising:

one or more electronic devices; and

a power feeding device configured to transmit electric power to said one or more electronic devices,

wherein said power feeding device includes

a power transmitting section which transmits electric power by way of a magnetic field,

a set of first and second electrodes which are spaced from each other,

a power supply which applies a voltage between said first and second electrodes, and

a detector which detects whether foreign matter is present on said power transmitting section or not based on the voltage applied by said power supply.

19. The power feeding system according to claim 18, wherein each of said one or more electronic devices comprises:

a metal member; and

an insulative member disposed on at least a portion of an outer surface of said metal member.

20. The power feeding system according to claim 19, wherein said insulative member comprises:

a plurality of teeth disposed on said outer surface of said metal member.