Wireless power transmitter, wireless power receiver, and method of wirelessly receiving power

• US 9,343,928 B2
• Filed: 12/12/2012
• Issued: 05/17/2016
• Est. Priority Date: 03/05/2012
• Status: Active Grant

• Current Assignee: Nera Innovations Limited (Atlantic IP Services Limited)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Bae, Su Ho
• Primary Examiner(s): Leja, Ronald W
• Application Number:
  US13/712,596
• Publication Number:
  US 20130229062A1
• Time in Patent Office: 1,252 Days
• Field of Search: 307/104
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Disclosed are a wireless power transmitter, a wireless power receiver, and a method of wirelessly receiving power. The wireless power receiver includes a receiving unit receiving the power from the wireless power transmitter using resonance, and a rectifying unit rectifying the power received therein from the receiving unit to supply the power to a load side. The rectifying unit changes an output impedance of the wireless power receiver in order to change an input current of the wireless power transmitter.

Claims

1. A wireless power receiver wirelessly receiving power from a wireless power transmitter, the wireless power receiver comprising:

a receiving unit receiving the power from the wireless power transmitter using resonance; and

a rectifying unit rectifying the power received therein from the receiving unit to supply the power to a load side,

wherein the rectifying unit changes an output impedance of the wireless power receiver in order to change an input current of the wireless power transmitter,

wherein the rectifying unit comprises;

a bridge diode comprising four diodes connected to each other; and

a switch changing a flow of current inputted from the receiving unit to the bridge diode,

wherein the bridge diode changes the output impedance as the toy of current is changed.

2. The wireless power receiver of claim 1, wherein the switch is opened or shorted in order to change the flow of current.

3. The wireless power receiver of claim 2, wherein the output impedance is an impedance measured when seen from the receiving unit to the rectifying unit.

4. The wireless power receiver of claim 1, wherein the output impedance is an impedance measured when seen from the receiving unit to the rectifying unit.

5. The wireless power receiver of claim 1, wherein the rectifying unit informs the wireless power transmitter of state information of the wireless power receiver as the input current of the wireless power transmitter is changed by changing the output impedance.

6. The wireless power receiver of claim 5, wherein the state information of the wireless power receiver includes one of power charge completion information of the wireless power receiver and a quantity of power charged in the wireless power receiver.

7. The wireless power receiver of claim 1, wherein the receiving unit comprises:

a reception resonance coil resonance-coupled with a transmission resonance coil of the wireless power transmitter to receive the power; and

a reception induction coil coupled with the reception resonance coil to receive the power.

8. A wireless power transmitter wirelessly transmitting power to a wireless power receiver, the wireless power transmitter comprises:

a transmission unit transmitting power, which is supplied from a power source, to the wireless power receiver using resonance; and

a detecting unit detecting input current of the wireless power transmitter to detect a change of an output impedance of the wireless power receiver by using the detected input current,

wherein the wireless power receiver changes the output impedance in order to change the input current,

wherein the wireless power receiver comprises;

a bridge diode comprising four diodes connected to each other; and

a switch changing a flow of current inputted to the bridge diode,

wherein the bridge diode changes the output impedance as the flow of current inputted to the bridge diode is changed.

9. The wireless power transmitter of claim 8, wherein the input impedance is an impedance measured when seen from the power source toward the wireless power transmitter.

10. The wireless power transmitter of claim 8, wherein the detecting unit detects the change of the output impedance of the wireless power receiver by detecting an average input current of the wireless power receiver during one cycle.

11. The wireless power transmitter of claim 8, wherein the transmission unit comprises:

a transmission induction coil receiving the power from the power source; and

a transmission resonance coil coupled with the transmission induction coil to transmit the received power to the wireless power receiver using resonance.

12. The wireless power transmitter of claim 8, further comprising a state information determining unit to determine state information of the wireless power receiver based on the detected change of the output impedance.

13. The wireless power transmitter of claim 12, further comprising a power controlling unit to control the power to be transmitted to the wireless power receiver according to the determined state information.

14. The wireless power receiver of claim 8, wherein the output impedance is an impedance measured when seen from a receiving unit of the wireless power receiver to a rectifying unit including the bridge diode and the switch.

15. A method of receiving power of a wireless power receiver for wirelessly receiving the power from a wireless power transmitter, the method comprising:

determining state information of the wireless power receiver to be transmitted to the wireless power transmitter;

changing an output impedance of the wireless power receiver according to the determined state information; and

receiving changed power from the wireless power transmitter according to the changed output impedance,

wherein the wireless power receiver comprises;

a bride diode comprising four diodes connected to each other; and

a switch changing a flow of current inputted to the bridge diode,

wherein the bridge diode changes the output impedance as the flow of current inputted to the bridge diode is changed.

16. The method of claim 15, wherein the switch is opened or shorted in order to change the flow of current inputted to the bridge diode.

17. The method of claim 15, wherein the receiving of the changed power from the wireless power transmitter according to the changed output impedance comprises:

changing an input current of the wireless power transmitter as the output impedance is changed and

receiving the changed power from the wireless power transmitter based on the changed input current.

18. The method of claim 15, wherein the state information of the wireless power receiver includes one of power charge completion information of the wireless power receiver and a quantity of power charged in the wireless power receiver.

19. The method of claim 15, wherein the output impedance of the wireless power receiver is an impedance measured when seen from a receiving unit provided in the wireless power receiver toward a rectifying unit including the bridge diode and the switch.

20. A recording medium recording a program for executing the method for receiving a power of the wireless power receiver claimed claim 15.