Wireless charging system

• US 8,120,316 B2
• Filed: 08/13/2009
• Issued: 02/21/2012
• Est. Priority Date: 04/08/2009
• Status: Expired due to Fees

• Current Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Inventors: Sip, Kim-Yeung
• Primary Examiner(s): Ramadan, Ramy
• Application Number:
  US12/541,126
• Publication Number:
  US 20100259214A1
• Time in Patent Office: 922 Days
• Field of Search: 320/108
• US Class Current: 320/108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

A wireless charging system charging an electronic device wirelessly via electromagnetic induction between a number of transmitting coils formed in the wireless charging system and a receiving coil formed in the electronic device. The wireless charging system selects the transmitting coil aligned with the receiving coil most accurately for transmitting electromagnetic energy in order to improving the energy conversion efficiency between the transmitting coil and the receiving coil.

Claims

1. A wireless charging system for charging a battery of an electronic device, the wireless charging system comprising:

a receiving coil in the electronic device connected to the battery;

a base;

a plurality of transmitting coils formed within the base, each of the plurality of transmitting coils is for transmitting electromagnetic energy which is capable of inducing a current in the receiving coil for charging the battery; and

a processor connected to the transmitting coils for selectively activating the transmitting coils one by one and detecting a load power value of each transmitting coil before charging, and activating the transmitting coil having the highest load power but inactivating the other transmitting coils when charging;

wherein the base comprising an upper surface, a lower surface, a first sidewall, and a second sidewall parallel to the first sidewall;

the upper surface defines a groove thereon; and

the groove comprises an open-end and a bottom surface;

wherein the transmitting coils are formed under the bottom surface of the base;

the transmitting coils are arranged in a matrix manner; and

each of the transmitting coils is assigned a positioning code for distinguishing each other;

wherein further comprising a power circuit connected to the transmitting coils for providing electrical power to the transmitting coils; and

wherein the processor comprises;

a detecting unit configured for selectively connecting the transmitting coils to the power circuit one by one and detecting the load power value of each of the transmitting coils;

a memory unit configured for storing the load power values and the corresponding positioning codes of the transmitting coils;

a comparing unit configured for comparing the load power value of each of the transmitting coils to locate the transmitting coil having the highest load power value; and

a selecting unit configured for connecting the transmitting coil having the highest load power value to the power circuit and disconnecting the other transmitting coils from the power circuit.

2. The wireless charging system as claimed in the claim 1, further comprising a fastening part;

the fastening part comprises a fixing strap, a first fastening piece, and a second fastening piece coupled with the first fastening piece;

the fixing strap is connected to the first sidewall using one end thereof, the first fastening piece is fixed at the other end of the fixing strap;

the second fastening piece is fixed on the lower surface near to the second sidewall; and

the fixing strap wraps around the electronic device with the first fastening piece coupled with the second fastening piece for fastening the electronic device on the bottom surface of the groove.

3. The wireless charging system as claimed in claim 2, wherein the first fastening piece and the second fastening piece are a pair of fabric hook-and-loop fasteners or a pair of snap fasteners.

4. The wireless charging system as claimed in claim 1, wherein the electronic device further comprises a charging circuit;

the receiving coil is induced by the electromagnetic energy and generates the alternating current, and the charging circuit converts the alternating current into the direct current for charging the battery.