POWER RECEIVING DEVICE, POWER TRANSMITTING DEVICE, WIRELESS POWER TRANSFER SYSTEM, AND WIRELESS POWER TRANSFER METHOD

• US 20130076153A1
• Filed: 09/13/2012
• Published: 03/28/2013
• Est. Priority Date: 09/26/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Murayama, Yuji, Nakano, Hiroaki, Fukuda, Shinichi
• Granted Patent: US 9,583,964 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• 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 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

Abstract

A power receiving unit includes a communication unit, a control unit, a detecting unit that performs metallic foreign matter detection, and a charge storage unit. The control unit is configured to control charging so electric power is stored in the charge storage unit for consumption by the detecting unit during Q-value measurement when the control unit receives a Q-value measurement command from the power transmitting device through the communication unit.

Claims

1. An energy receiver comprising:

a power reception coil configured to wirelessly receive power from an energy transmitter;

a foreign object detector configured to detect a foreign object within a range of a wireless energy transmission of the energy transmitter; and

an energy storage element configured to store power received from the energy transmitter after receiving a command related to detection of the foreign object.

2. The energy receiver of claim 1, further comprising:

a control unit configured to supply power to the foreign object detector from the energy storage element when the energy transmitter is not transmitting power.

3. The energy receiver of claim 2, wherein the control unit is configured to supply the power to the foreign object detector from the energy storage element after receiving data corresponding to identification information of the energy receiver.

4. The energy receiver of claim 2,

wherein,

if the command includes identification information related to the energy receiver, the control unit causes (i) the energy storage element to store power, and (ii) the foreign object detector to search for the foreign object, and

if the command does not include identification information related to the energy receiver, the control unit only causes the energy storage element to store power.

5. The energy receiver of claim 2,

wherein,

the foreign object detector is configured to use power stored in the energy storage element to detect the foreign object when the wireless energy transmission is suspended, and

the control unit is configured to cause a result generated by the foreign object detector to the energy transmitter when the wireless energy transmission is restarted after a suspension of the wireless energy transmission, the result related to whether the foreign object was detected by the foreign object detector.

6. The energy receiver of claim 2 wherein the control unit is configured to cause the power received by the power reception coil from the energy transmitter to be supplied to a load connected to the energy receiver upon receipt of a charging command from the energy transmitter.

7. The energy receiver of claim 2, wherein the control unit, upon receipt of the command, is configured to cause (i) the energy storage element to store power, and (ii) the foreign object detector to search for the foreign object.

8. The energy receiver of claim 1, wherein the energy storage element is a capacitor or a small secondary battery.

9. The energy receiver of claim 1, wherein the foreign object detector is a Q-value measurement circuit configured to detect a quality factor related to a resonance circuit.

10. The energy receiver of claim 1, further comprising:

a memory configured to store identification information of the energy receiver.

11. A detection method comprising:

transmitting a first command from an energy transmitter to identify one or more energy receivers operable to wirelessly receive power from the energy transmitter;

transmitting identification information from each of the one or more energy receivers to the energy transmitter upon receipt of the first command; and

transmitting a second command to activate a foreign object detection process configured to detect a foreign object within a range of a wireless energy transmission of the energy transmitter,

wherein each of the one or more energy receivers is configured to independently store power received from the energy transmitter in an energy storage element after receiving the second command to activate the foreign object detector process.

12. The detection method of claim 11, further comprising:

powering the foreign object detection process using power stored by the energy storage element when the energy transmitter is not transmitting power.

13. The detection method of claim 12, wherein the foreign object detection process is performed using a Q-value measurement circuit configured to detect a quality factor related to a resonance circuit.

14. An energy transmitter comprising:

a power transmission coil configured to wirelessly transmit power to at least one energy receiver; and

a communication unit configured to activate a power storage process in the at least one energy receiver by transmitting a command to activate a foreign object detection process configured to detect a foreign object within a range of a wireless energy transmission of the energy transmitter.

15. The energy transmitter of claim 14,

wherein,

the at least one energy receiver includes a plurality of energy receivers, and

the communication unit is configured to independently control each of the plurality of energy receivers using different identification information.

16. The energy transmitter of claim 14, wherein the foreign object detection process is performed via a Q-value measurement circuit configured to detect a quality factor related to a resonance circuit.

17. The energy transmitter of claim 14, wherein the energy transmitter is configured to transmit power during the power storage process for a fixed period of time required to store power to run the Q-value measurement circuit to perform a Q-value measurement.

18. The energy transmitter of claim 17, wherein the energy transmitter is configured to temporarily suspend transmission of the power for a fixed period of time required for the Q-value measurement circuit to perform one Q-value measurement.

19. A detection device comprising:

a foreign object detector configured to detect a foreign object within a range of a wireless transmission of power between an energy receiver and an energy transmitter; and

an energy storage element configured to store power received from the energy transmitter upon receipt of a command related to detection of the foreign object.

20. The detection device of claim 19, further comprising:

a control unit configured to supply power to the foreign object detector from the energy storage element when the energy transmitter is not transmitting power.

21. The detection device of claim 19, wherein the foreign object detector is a Q-value measurement circuit configured to detect a quality factor related to a resonance circuit.