Wireless power transmitter using a resonance coil via a resonance frequency band and corresponding method

1. A wireless power transmission method of a wireless power transmitter for transmitting power using a resonance coil via a resonance frequency band to a wireless power receiver, the wireless power transmission method comprising:

transmitting a connection signal for identifying a first wireless power receiver;

identifying the first wireless power receiver by receiving a response signal corresponding to the connection signal from the first wireless power receiver;

transmitting state information of the wireless power transmitter to the first wireless power receiver via a specific frequency band, wherein the state information comprises an available amount of power of the wireless power transmitter;

receiving first specific state information from the first wireless power receiver via the specific frequency band, wherein the first specific state information comprises a demanded amount of power of the first wireless power receiver, and wherein the demanded amount of power is adjusted by the first wireless power receiver within the available amount of power of the wireless power transmitter; and

transmitting the power to the first wireless power receiver according to the first specific state information via the resonance frequency band being a resonance-coupled frequency between the wireless power transmitter and the first wireless power receiver and being different from the specific frequency band.

2. The wireless power transmission method of claim 1 , further comprising:

detecting a second wireless power receiver during the transmitting of the power to the first wireless power receiver;

transmitting a first state information of the wireless power transmitter to the first wireless power receiver and a second state information of the wireless power transmitter to the second wireless power receiver; and

receiving the first specific state information from the first wireless power receiver and second specific state information from the second wireless power receiver,

wherein the first and second state information of the wireless power transmitter includes information about a differential ratio of the power transmission corresponding to the first and second wireless power receivers respectively.

3. The wireless power transmission method of claim 2 , wherein the first state information of the wireless power transmitter includes dedicated identification information for the first wireless power receiver, and

wherein the second state information of the wireless power transmitter includes dedicated identification information for the second wireless power receiver.

4. The wireless power transmission method of claim 2 , wherein the demanded amount of power is adjusted by the second wireless power receiver within the available amount of power of the wireless power transmitter, and

wherein the first and second specific state information includes the adjusted demanded power information based on the differential ratio of the power transmission.

5. The wireless power transmission method of claim 2 , further comprising:

checking whether a number of the wireless power receivers connected to the wireless power transmitter exceeds a number of wireless power receivers supportable by the wireless power transmitter; and

transmitting the power to the second wireless power receiver via the resonance frequency band according to the demanded amount of power of the second wireless power receiver if the number of the wireless power receivers connected to the wireless power transmitter is equal to or less than the number of wireless power receivers supportable by the wireless power transmitter.

6. The wireless power transmission method of claim 1 , wherein the wireless power transmitter adjusts the power based on a priority of the first wireless power receiver.

7. The wireless power transmission method of claim 1 , wherein the wireless power transmitter negotiates a power transmission condition with the first wireless power receiver through out-of-band bidirectional communication.

8. The wireless power transmission method of claim 1 , further comprising transmitting the connection signal to another wireless power receiver when the response signal is not received in the wireless power transmitter.

9. The wireless power transmission method of claim 1 , further comprising:

transmitting a state list of a plurality of wireless power transmitters to the first wireless power receiver to select at least one of the wireless power transmitters; and

receiving selection information corresponding to the selection of at least one wireless power transmitter from the first wireless power receiver,

wherein the transmission of the power to the first wireless power receiver comprises:

transmitting the power from the selected at least one wireless power transmitter to the first wireless power receiver.

10. A wireless power transmitter using a resonance coil via a resonance frequency band to a wireless power receiver, the wireless power transmitter comprising:

a transmitting unit configured to transmit a connection signal for identifying a first wireless power receiver;

an identifying unit configured to identify the first wireless power receiver by receiving a response signal corresponding to the connection signal from the first wireless power receiver; and

a control unit configured to:

control the transmitting unit to transmit state information of the wireless power transmitter to the first wireless power receiver via a specific frequency band, the state information including an available amount of power of the wireless power transmitter,

receive first specific state information from the first wireless power receiver via the specific frequency band, the first specific state information including a demanded amount of power of the first wireless power, wherein the demanded amount of power is adjusted by the first wireless power receiver within the available amount of power of the wireless power transmitter, and

control the transmitting unit to transmit the power to the first wireless power receiver according to the first specific state information via the resonance frequency band being a resonance-coupled frequency between the wireless power transmitter and the first wireless power receiver and being different from the specific frequency band.

11. The wireless power transmitter of claim 10 , wherein the

control unit is further configured to:

detect a second wireless power receiver during the transmitting of the power to the first wireless power receiver,

control the transmitting unit to transmit a first state information of the wireless power transmitter to the first wireless power receiver and a second state information of the wireless power transmitter to the second wireless power receiver, and

receive the first specific state information from the first wireless power receiver and second specific state information from the second wireless power receiver, and

wherein the first and second state information of the wireless power transmitter includes information about a differential ratio of the power transmission corresponding to the first and second wireless power receivers respectively.

12. The wireless power transmitter of claim 11 , wherein the first specific state information of the wireless power transmitter includes dedicated identification information for the first wireless power receiver, and

wherein the second specific state information of the wireless power transmitter includes dedicated identification information for the second wireless power receiver.

13. The wireless power transmitter of claim 11 , wherein the first specific state information further includes present charging information in the first wireless power receiver.

14. The wireless power transmitter of claim 11 , wherein the control unit is further configured to:

check whether a number of the wireless power receivers connected to the wireless power transmitter exceeds the number of wireless power receivers supportable by the wireless power transmitter, and

transmit the power to the second wireless power receiver via the resonance frequency band according to the demanded amount of power of the second wireless power receiver if the number of the wireless power receivers connected to the wireless power transmitter is equal to or less than the number of wireless power receivers supportable by the wireless power transmitter.

15. The wireless power transmitter of claim 10 , wherein the control unit is further configured to adjust the power transmitted by the transmitting unit based on a priority of the first wireless power receiver.

16. The wireless power transmitter of claim 10 , further comprising:

a negotiating unit configured to negotiate a power transmission condition with the first wireless power receiver through out-of-band bidirectional communication.

17. The wireless power transmitter of claim 16 , wherein the out-of-band bidirectional communication includes at least one of Bluetooth, Zig-bee, WLAN, and NFC.

18. The wireless power transmitter of claim 10 , wherein the transmitting unit is further configured to transmit the power to the first wireless power receiver using a transmission resonant coil.