Wireless power multi-charging method and power transmitter

1. A wireless multi-charging method of a power transmitter that wirelessly transmits power, the method comprising:

sensing a first power receiver;

increasing a transmission power required for charging the first power receiver when sensing the first power receiver;

sensing a second power receiver;

decreasing the transmission power required for suspending charging of the first power receiver when sensing the second power receiver; and

increasing the transmission power required for simultaneously charging both the first power receiver and the second power receiver.

2. The method of claim 1 , further comprising:

supplying, to the first power receiver, a communication power required for communication with the first power receiver.

3. The method of claim 1 , further comprising:

receiving a registration request message from the first power receiver; and

transmitting, to the first power receiver, a registration response message including identification information of the first power receiver, in response to the registration request message.

4. The method of claim 3 , further comprising:

comparing identification information received through the registration request message and identification information stored in advance; and

allowing registration of the first power receiver when the received identification information is identical to the identification information stored in advance.

5. The method of claim 1 , further comprising:

receiving, from the first power receiver, a charging request message including information regarding an amount of power required for charging; and

transmitting, to the first power receiver, a charging response message that allows the request for charging, in response to the charging request message.

6. The method of claim 5 , further comprising:

comparing the amount of power required for charging and an amount of available power; and

allowing the request for charging when the amount of power required for charging is less than or equal to the amount of available power.

7. The method of claim 1 , further comprising:

transmitting, to the first power receiver, a notice message including first charge state information of the power transmitter; and

receiving, from the first power receiver, a report message including second charge state information of the first power receiver.

8. The method of claim 7 , wherein the first charge state information includes sync information, charge start information, reset information, charge finish information, or an error situation, and the second charge state information includes an amount of power required for charging, an amount of power received from the power transmitter, a charge state, or an error situation.

9. The method of claim 1 , further comprising:

supplying, to the second power receiver, a communication power required for communication with the second receiver when the second power receiver is sensed.

10. The method of claim 1 , wherein, when the transmission power is decreased, a communication power required for communication with the first power receiver and the second power receiver is supplied to the first power receiver and the second power receiver.

11. A power transmitter for wireless multi-charging, the power transmitter comprising:

a resonator configured to generate a Radio Frequency (RF) field, and to wirelessly transmit power to a first power receiver and a second power receiver through the RF field;

a sensor unit configured to sense the first power receiver and the second power receiver; and

a controller configured to increase a transmission power to charge the first power receiver when the first power receiver is sensed, decrease the transmission power to suspend charging the first power receiver when the second power receiver is sensed, and increase the transmission power to simultaneously charge the first power receiver and the second power receiver.

12. The power transmitter of claim 11 , further comprising:

a communication unit configured to perform wireless communication with the first power receiver and the second power receiver,

wherein the controller is further configured to receive a registration request message from the first power receiver, and transmit, to the first power receiver, a registration response message including identification information of the first power receiver, in response to the registration request message.

13. The power transmitter of claim 12 , further comprising:

a memory configured to store identification information regarding chargeable power receivers,

wherein the controller is further configured to compare identification information received through the registration request message and identification information stored in the memory, and allow registration of the first power receiver when the received identification information is identical to identification information stored in advance.

14. The power transmitter of claim 11 , wherein the controller is further configured to receive, from the first power receiver, a charging request message including information regarding an amount of power required for charging, compare the amount of power required for charging and an amount of available power, and transmit, to the first power receiver, a charging response message that allows the request for charging, in response to the charging request message, when the amount of power required for charging is less than or equal to the amount of available power.

15. The power transmitter of claim 11 , wherein the controller is further configured to supply, to the first power receiver and the second power receiver, a communication power required for communication with the first power receiver and the second power receiver when the transmission power is decreased.