SYSTEM AND METHOD FOR FACILITATING AVOIDANCE OF WIRELESS CHARGING CROSS CONNECTION

• US 20170256979A1
• Filed: 05/18/2017
• Published: 09/07/2017
• Est. Priority Date: 12/12/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Von Novak, William H., Kallal, Edward
• Granted Patent: US 10,734,841 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A system and method for charging a chargeable device is provided. The system can include a wireless charger including a wireless power antenna and a wireless power transmitter coupled to the wireless power antenna and configured to generate a wireless charging field in at least one charging region. The wireless charging field includes a plurality of power signals. The wireless charger further includes a communication antenna and a transceiver coupled to the communication antenna and configured to communicate with the chargeable device via the communication antenna. The wireless charger further includes a controller configured to facilitate avoidance of cross connection of the chargeable device with the wireless charger and at least one other wireless charger in which the chargeable device receives power from the wireless power transmitter of the wireless charger while communicating with at least one other wireless charger. The system can include a chargeable device including a controller configured to generate a load pulse configured to be received by the wireless charger.

Claims

1. A method of communication between a chargeable device and a wireless charger, the method comprising:

detecting an impedance change in at least one charging region of a wireless charging field generated by the wireless charger, the impedance change caused by introducing the chargeable device to the wireless charging field;

determining whether the detected impedance change has a predetermined attribute based on the detected impedance change; and

detecting a communication signal from the chargeable device during a first predetermined period of time along with detecting an impedance change having the predetermined attribute.

2. The method of claim 1, wherein the predetermined attribute comprises an impedance change greater than a predetermined amount.

3. The method of claim 1, wherein the predetermined period of time is in a range of one second to 10 seconds.

4. The method of claim 1, further comprising establishing a communication link with the chargeable device when the wireless charger receives the communication signal within the first predetermined time after detecting the impedance change.

6. The method of claim 1, further comprising declining accepting communication signals for a second period of time upon no impedance change being detected, and accepting communication signals during a third predetermined period of time after detecting an impedance change not having the predetermined attribute.

7. The method of claim 1, further comprising generating a plurality of power signals by modulating the wireless charging field by an amplitude that is sufficiently low so as to not affect power transmission but sufficiently high to be detected by the chargeable device.

8. The method of claim 7, wherein modulating the wireless charging field comprises modulating the wireless charging field in a pattern that is unique to the wireless charger.

9. The method of claim 1, further comprising detecting whether the detected impedance change from the chargeable device and an advertisement from the chargeable device are concurrent with one another.

5. The method of claim 5, wherein the communication link is established when a received signal strength indication (RSSI) of the communication signal is larger than a predetermined threshold.

10. A method of communication between a chargeable device and a wireless charger, the method comprising:

detecting a load pulse from a chargeable device;

detecting an communication signal from a chargeable device;

evaluating a time period between detecting the load pulse and detecting the communication signal; and

transmitting a response to the communication signal if the time period is less than a predetermined time period.

11. The method of claim 10, wherein the predetermined time period is selected to be indicative of the load pulse and the communication signal being sent by the same chargeable device.

12. The method of claim 10, further comprising, if the time period is less than the predetermined time period, placing the chargeable device on a list of accepted chargeable devices and beginning charging the chargeable device.

13. The method of claim 10, further comprising determining that the detected load pulse exceeds a first threshold value before transmitting the response.

14. The method of claim 11, wherein the detected impedance change comprises a train of load pulses or a tone burst of impedance modulation.

16. The method of claim 14, further comprising accepting additional communication signals from the chargeable device in response to determining a signal strength of the communication signal is above a signal strength threshold and that an amount of the impedance change is above an impedance change threshold.

17. The method of claim 14, wherein detecting the impedance change in the wireless charging field comprises detecting the impedance change in the wireless field within the first time period before receiving the communication signal.

18. The method of claim 14, wherein detecting the impedance change in the wireless charging field comprises detecting the impedance change in the wireless field within the first time period after receiving the communication signal.

19. The method of claim 14, wherein the communication signal is received via an communication channel different than the wireless field, and wherein the communication signal is received during a beacon mode time period.

20. The method of claim 14, wherein the detected impedance change comprises a train of load pulses or a tone burst of impedance modulation.

15. A method of communication between a chargeable device and a wireless charger, the method comprising:

detecting a communication signal from a chargeable device;

detecting an impedance change in a wireless charging field generated by the wireless charger within a first time period of receiving the communication signal, the impedance change greater than or equal to a first threshold value and lasting for at least a first duration; and

terminating a communication link with the chargeable device when the detected impedance change is not greater than or equal to the first threshold value or does not last for at least the first duration within a first period of time.