Wireless power transmitting unit, wireless power receiving unit, and control methods thereof

1. A control method of a wireless power receiving unit receiving charging power from a wireless power transmitting unit to perform wireless charging, the control method comprising:

receiving the charging power from the wireless power transmitting unit;

detecting a change in a wireless charging environment;

generating a message notifying of the change in the wireless charging environment; and

transmitting the message notifying of the change in the wireless charging environment to the wireless power transmitting unit.

2. The control method of claim 1 , wherein the detecting the change in the wireless charging environment comprises detecting a mode transition from a Stand Alone (SA) mode to a Non Stand Alone (NSA) mode.

3. The control method of claim 2 , wherein the message notifying of the change in the wireless charging environment is a mode transition notification message.

4. The control method of claim 3 , wherein the generating the message notifying of the change in the wireless charging environment comprises generating a Power Receiving Unit (PRU) dynamic signal or a PRU alert signal.

5. The control method of claim 4 , wherein the PRU alert signal includes a time required when the mode transition is completed.

6. The control method of claim 2 , further comprising, when the mode transition is detected, loading a stack of a communication scheme of the wireless power receiving unit from an Application Processor (AP) of the wireless power receiving unit.

7. A wireless power receiving unit receiving charging power from a wireless power transmitting unit to perform wireless charging, the wireless power receiving unit comprising:

a power receiver configured to receive the charging power from the wireless power transmitting unit; and

a communication unit configured to, if a mode transition is detected, transmit a mode transition notification for requesting the wireless power transmitting unit to maintain transmitting the charging power for a duration of the mode transition.

8. The wireless power receiving unit of claim 7 , wherein the communication unit is a WiFi/Bluetooth Combo IC.

9. The wireless power receiving unit of claim 7 , further comprising an Application Processor (AP) that controls an operation of the wireless power receiving unit and includes a memory storing a stack of a communication scheme of the wireless power receiving unit.

10. The wireless power receiving unit of claim 9 , wherein the communication unit detects the mode transition from a Stand Alone (SA) mode in which the stack of the communication scheme of the wireless power receiving unit is loaded from a memory within the communication unit to a Non Stand Alone (NSA) mode in which the stack is loaded from the memory within the AP.

11. The wireless power receiving unit of claim 7 , wherein the mode transition notification uses a Power Receiving Unit (PRU) dynamic signal or a PRU alert signal.

12. The wireless power receiving unit of claim 11 , wherein the PRU alert signal includes information regarding the duration of the mode transition.

13. The wireless power receiving unit of claim 12 , wherein the information regarding the duration of the mode transition includes one of bits for the mode transition, and

wherein the bits for the mode transition are 00, 01, 10, and 11.

14. The control method of claim 13 , wherein the 00 indicates no mode transition, the 01 indicates that the duration of the mode transition is 2 seconds, the 10 indicates that the duration of the mode transition is 3 seconds, and the 11 indicates that the duration of the mode transition is 6 seconds.

15. The wireless power receiving unit of claim 13 , wherein the 00 indicates no mode transition, the 01 indicates that the duration of the mode transition is 2 seconds, the 10 indicates that the duration of the mode transition is 3 seconds, and the 11 indicates that the duration of the mode transition is 6 seconds.

16. A control method of a wireless power transmitting unit transmitting charging power to a wireless power receiving unit to perform wireless charging, the control method comprising:

transmitting the charging power to the wireless power receiving unit;

receiving, from the wireless power receiving unit, a mode transition notification including a request for maintaining transmitting the charging power for a duration of a mode transition; and

maintaining the transmitting the charging power to the wireless power receiving unit for the duration of the mode transition.

17. The control method of claim 16 , wherein the mode transition notification includes a Power Receiving Unit (PRU) alert signal.

18. The control method of claim 17 , wherein the PRU alert signal includes information regarding the duration of the mode transition.

19. The control method of claim 18 , wherein the information regarding the duration of the mode transition includes one of bits for the mode transition, and

wherein the bits for the mode transition are 00, 01, 10, and 11.