POWER RECEPTION DEVICE, POWER TRANSMISSION DEVICE AND WIRELESS POWER TRANSMISSION SYSTEM

• US 20140210276A1
• Filed: 03/28/2014
• Published: 07/31/2014
• Est. Priority Date: 10/28/2011
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Ichikawa, Keiichi, Shinoda, Satoshi
• Granted Patent: US 9,755,460 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/05 using capacitive coupling
• 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 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H04B 5/22 Capacitive coupling
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A mobile terminal device performs short range communication with an R/W device and receives power from a power transmission device. The mobile terminal device includes a coil antenna, an RFID IC circuit that performs short range communication with the outside via the coil antenna, a charging circuit that receives power received by the coil antenna which is capacitively coupled with a passive electrode and switches that switch to a short range communication state in which short range communication is performed via the coil antenna or a power reception state in which power is received via the coil antenna. Accordingly, a power reception device, a power transmission device and a wireless power transmission system are provided with which wireless power transmission can be realized without obstructing size reduction by giving a single member two functions.

Claims

1. A power reception device comprising:

a loop-shaped conductor;

a communication circuit configured to wirelessly communicate data via the loop-shaped conductor;

a power reception circuit configured to receive power from the loop-shaped conductor when the loop-shaped conductor is capacitively coupled with an active electrode of a power transmission device; and

a switching circuit configured to electrically couple the loop-shaped conductor to the communication circuit in a data communication state and to electrically couple the loop-shaped conductor to the power reception circuit in a power reception state.

2. The power reception device according to claim 1,

wherein the loop-shaped conductor includes a first end and a second end,

wherein the switching circuit includes a first switch that selectively connects the first end of the loop-shaped conductor to the communication circuit or the power reception circuit, and a second switch that selectively connects the second end of the loop-shaped conductor to the communication circuit,

wherein, when the power reception device is in the data communication state, the second switch connects the second end of the loop-shaped conductor to the communication circuit, and the first switch connects the first end of the loop-shaped conductor to the communication circuit, and

wherein, when the power reception device is in the power reception state, the second switch disconnects the second end of the loop-shaped conductor from the communication circuit, and the first switch connects the first end of the loop-shaped conductor to the power reception circuit.

3. The power reception device according to claim 1, further comprising:

a detection circuit configured to generate a detection signal that indicates whether the loop-shaped conductor is receiving a data communication signal or a power transmission signal, and

wherein the switching circuit is configured to switch the power reception device to one of the power reception state and the data communication state based on the detection signal.

4. The power reception device according to claim 1, wherein the switching circuit includes:

a first filter coupled between the loop-shaped conductor and the communication circuit, the first filter configured to pass a data communication signal having a first frequency to the communication circuit and to block a power reception signal having a second frequency to the power reception circuit, and

a second filter coupled between the loop-shaped conductor and the power reception circuit, the second filter configured to pass the power reception signal to the power reception circuit and to block the data communication signal from the communication circuit.

5. The power reception device according to claim 1, further comprising:

a coupling electrode that is adjacent to a passive electrode of the power transmission device when the loop-shaped conductor is capacitively coupled with the active electrode of the power transmission device,

wherein a voltage generated between the loop-shaped conductor and the coupling electrode is applied to the power reception circuit.

6. The power reception device according to claim 5,

wherein the coupling electrode is disposed in the power reception device such that a direction normal thereto coincides with a winding axis direction of the loop-shaped conductor and the loop-shaped conductor is disposed adjacent to the active electrode side and the passive electrode side of the coupling electrode.

7. The power reception device according to claim 6, wherein an area of the coupling electrode is larger than a planar area of the loop-shaped conductor.

8. A power transmission device comprising:

a loop-shaped conductor;

a communication circuit configured to wirelessly communicate data via the loop-shaped conductor;

a power transmission circuit configured to transmit power to an active electrode of a power reception device via the loop-shaped conductor when the active electrode is capacitively coupled to the loop-shaped conductor; and

a switching circuit configured to electrically couple the loop-shaped conductor to the communication circuit in a data communication state and to electrically couple the loop-shaped conductor to the power transmission circuit in a power transmission state.

9. The power transmission device according to claim 8,

wherein the loop-shaped conductor has a first end and a second end,

wherein the switching circuit includes a first switch that selectively connects the first end of the loop-shaped conductor to the communication circuit or the power transmission circuit, and a second switch that selectively connects the second end of the loop-shaped conductor to the communication circuit, and

wherein, when the power transmission device is in the data communication state, the first switch connects the first end of the loop-shaped conductor to the communication circuit and the second switch connects the second end of the loop-shaped conductor to the communication circuit, and

wherein, when the power transmission device is in the power transmission state, the second switch disconnects the second end of the loop-shaped conductor from the communication circuit and the first switch connects the first end of the loop-shaped conductor to the power transmission circuit.

10. The power transmission device according to claim 8, further comprising:

a detection circuit configured to generate a detection signal that indicates whether the loop-shaped conductor is receiving a data communication signal or a power transmission signal, and

wherein the switching circuit is configured to switch the power transmission device to one of the power transmission state and the data communication stated based on the detection signal.

11. The power transmission device according to claim 8, further comprising:

a coupling electrode that is adjacent to a passive electrode of the power receiving device when the loop-shaped conductor is capacitively coupled with the active electrode of the power receiving device.

12. The power transmission device according to claim 11, wherein the coupling electrode is disposed in the power transmission device such that a direction normal thereto coincides with a winding axis direction of the loop-shaped conductor and that the loop-shaped conductor is disposed adjacent to the active electrode side and the passive electrode side of the coupling electrode.

13. The power transmission device according to claim 12, wherein an area of the coupling electrode is larger than a planar area of the loop-shaped conductor.

14. A wireless power transmission system comprising:

a power transmission device having;

a power transmission side electrode, and

a voltage generating circuit configured to apply a voltage to the power transmission side electrode; and

a power reception device having;

a power reception side electrode capacitively coupled with the power transmission side electrode,

a power reception circuit configured to receive power from the power transmission device through capacitive coupling of the power reception side electrode,

a communication circuit configured to wireless communicate data via the power reception side electrode, and

a switching circuit configured to electrically couple the power reception side electrode to the communication circuit in a communication state and to electrically couple the power reception side electrode to the power reception circuit in a power reception state.

15. The wireless power transmission system according to claim 14, wherein the power reception side electrode is a loop-shaped conductor.

16. The wireless power transmission system according to claim 14, wherein the power transmission device further comprises:

a communication circuit configured to wirelessly communicate data via the power transmission side electrode;

a power transmission circuit configured to transmit power to the power reception side electrode of the power reception device via the power transmission side electrode, when the power transmission side electrode is capacitively couple with the power reception side electrode; and

a switching circuit configured to electrically couple the power transmission side electrode to the communication circuit in a data communication state and to electrically couple the power transmission side electrode to the power transmission circuit in a power transmission state.

17. A wireless power transmission system comprising

a power reception device having a power reception side electrode;

and

a power transmission device having;

a power transmission side electrode capacitively coupled with the power reception side electrode,

a voltage generating circuit configured to apply a voltage to the power transmission side electrode,

a communication circuit to wirelessly communicate data via the power transmission side electrode,

a switching circuit configured to electrically couple the power transmission side electrode to the communication circuit in a data communication state and to electrically couple the power transmission side electrode to the voltage generating circuit in a power transmission state.

18. The wireless power transmission system according to claim 17, wherein the power transmission side electrode is a loop-shaped conductor.

19. The wireless power transmission system according to claim 17, wherein the power reception device further comprises:

a communication circuit configured to wirelessly communicate data via the power reception side electrode;

a power reception circuit configured to receive power from the power transmission side electrode of the power transmission device via the power transmission side electrode, when the power reception side electrode is capacitively couple with the power transmission side electrode; and

a switching circuit configured to electrically couple the power reception side electrode to the communication circuit in a data communication state and to electrically couple the power reception side electrode to the power reception circuit in a power receiving state.