Wireless power transmission device and wireless power transmission method
A wireless power transmission device according to one embodiment of the present specification transmits wireless power to a wireless power reception device, and comprises: a power conversion circuit that transmits the wireless power to the wireless power reception device; and a communication/control circuit that communicates with the wireless power reception device and controls the wireless power, wherein the communication/control circuit transmits, to the wireless power reception device, a data packet comprising information on a number of slots and the length of the slots, for performing detection of foreign substances using the slots.
1. A wireless power transmitter for transferring a wireless power to a wireless power receiver comprising:
a power converter configured to transfer the wireless power to the wireless power receiver; and
a communicator/controller configured to control the wireless power,
wherein the wireless power transmitter
enters a negotiation phase with the wireless power receiver;
receives, from the wireless power receiver in the negotiation phase, a general request (GRQ) data packet for a capability (CAP) data packet;
transmits, to the wireless power receiver in the negotiation phase, the CAP data packet including a negotiable load power for the wireless power transmitter in response to the GRQ data packet for the CAP data packet;
receives, from the wireless power receiver in the negotiation phase, a GRQ data packet for an extended capability (XCAP) data packet;
transmits, to the wireless power receiver in the negotiation phase, the XCAP data packet including information for a minimum slot length,
wherein the minimum slot length is related to a length of a shortest slot which the wireless power transmitter supports,
enters a power transfer phase with the wireless power receiver after the negotiation phase;
transfers, to the wireless power receiver in the power transfer phase, the wireless power; and
receives, from the wireless power receiver in the power transfer phase, a specific data packet related to a slotted foreign object detection,
performs the slotted foreign object detection in the power transfer phase based on receiving the specific data packet,
wherein, in the slotted foreign object detection, the wireless power transmitter generates a slot, stops the transfer of the wireless power during the slot and detects whether a foreign object is present on the slot,
wherein the wireless power transmitter resumes the transfer of the wireless power after the slot has elapsed, and
wherein a length of the slot is equal to or longer than the minimum slot length.
2. The wireless power transmitter of claim 1 , wherein the information for the minimum slot length is expressed by 3 bits.
3. The wireless power transmitter of claim 1 , wherein the information for the minimum slot length having a value of 0 means that the wireless power transmitter does not support a foreign object detection based on a slot.
4. The wireless power transmitter of claim 1 , wherein the minimum slot length is 200 μsec or less.
5. A method for transferring a wireless power to a wireless power receiver, the method performed by a wireless power transmitter and comprising:
entering a negotiation phase with the wireless power receiver;
receiving, from the wireless power receiver in the negotiation phase, a general request (GRQ) data packet for a capability (CAP) data packet;
transmitting, to the wireless power receiver in the negotiation phase, the CAP data packet including a negotiable load power for the wireless power transmitter in response to the GRQ data packet for the CAP data packet;
receiving, from the wireless power receiver in the negotiation phase, a GRQ data packet for an extended capability (XCAP) data packet;
transmitting, to the wireless power receiver in the negotiation phase, the XCAP data packet including information for a minimum slot length,
wherein the minimum slot length is related to a length of a shortest slot which the wireless power transmitter supports;
entering a power transfer phase with the wireless power receiver after the negotiation phase;
transferring, to the wireless power receiver in the power transfer phase, the wireless power; and
receiving, from the wireless power receiver in the power transfer phase, a specific data packet related to a slotted foreign object detection,
performing the slotted foreign object detection in the power transfer phase based on receiving the specific data packet,
wherein, in the slotted foreign object detection, the wireless power transmitter generates a slot, stops the transfer of the wireless power during the slot and detects whether a foreign object is present on the slot,
wherein the wireless power transmitter resumes the transfer of the wireless power after the slot has elapsed, and
wherein a length of the slot is equal to or longer than the minimum slot length.
6. The method of claim 5 , wherein the information for the minimum slot length is expressed by 3 bits.
7. The method of claim 5 , wherein the information for the minimum slot length having a value of 0 means that the wireless power transmitter does not support a foreign object detection based on a slot.
8. The method of claim 5 , wherein the minimum slot length is 200 μsec or less.