Wireless charging system and method

• US 8,432,129 B2
• Filed: 12/22/2009
• Issued: 04/30/2013
• Est. Priority Date: 12/24/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Chang Ki, Jung, Won Bae
• Primary Examiner(s): Muralidar, Richard V
• Application Number:
  US12/655,021
• Publication Number:
  US 20100156347A1
• Time in Patent Office: 1,225 Days
• Field of Search: 320/108, 455/41.1, 4553431-3436, 455/573, 340/538.16, 340/854.8, 340/870.31, 340/870.32
• US Class Current: 320/108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

A wireless charging system can optimize charging efficiency regardless of a location of a mobile terminal. The wireless charging system wirelessly charges a mobile terminal using electromagnetic induction between a first coil included in a charging pad and a second coil included in the mobile terminal. The charging pad can detect a location of the mobile terminal on the charging pad. The charging pad can move the first coil to correspond to the detected location of the mobile terminal; and supply power to the first coil and charging a battery.

Claims

1. A method for wirelessly charging a mobile terminal using electromagnetic induction between a first coil included in a charging pad and a second coil included in the mobile terminal, the method comprising:

detecting a location of the mobile terminal on the charging pad;

moving the first coil to correspond to the detected location of the mobile terminal;

supplying power to the first coil for charging a battery in the mobile terminal; and

when a charging efficiency is less than a preset reference value, receiving from the mobile terminal a control signal requesting a location movement of the first coil, and moving a location of the first coil according to the control signal.

2. The method of claim 1, further comprising determining whether the mobile terminal is a certified device.

3. The method of claim 1, wherein the charging efficiency is determined at the mobile terminal.

4. The method of claim 1, further comprising:

when electric charging of the battery is complete, receiving from the mobile terminal a charging completion message.

5. The method of claim 4, further comprising, when the charging completion message is received, interrupting power supplied to the first coil.

6. The method of claim 5, further comprising moving, by the charging pad, the first coil not to correspond to the second coil.

7. A wireless charging system using electromagnetic induction, the wireless charging system comprising:

a charging pad comprising a first coil configured to generate a magnetic field when power is supplied; and

a mobile terminal comprising a second coil configured to charge a battery using an induction current induced to the second coil when the magnetic field is generated in the first coil;

wherein the charging pad is configured to determine a contact location of the mobile terminal and move the first coil to correspond to the location of the mobile terminal,

wherein the mobile terminal is configured to determine a charging efficiency and, when the charging efficiency is less than a preset reference value, transmit a control signal requesting a location movement of the first coil to the charging pad.

8. The wireless charging system of claim 7, wherein the charging pad comprises:

a detection unit configured to detect a contact location of the mobile terminal;

a driver adapted to enable movement of the first coil to correspond to the detected location of the mobile terminal;

a first controller configured to determine whether the detected mobile terminal is a certified device and control, if the detected mobile terminal is a certified device, wireless charging; and

a first storage unit configured to store first certification information for determining whether the mobile terminal is a chargeable device.

9. The wireless charging system of claim 8, wherein when the control signal for requesting the location movement of the first coil is received from the mobile terminal, the first controller controls the driver to move a location of the first coil.

10. The wireless charging system of claim 8, wherein when a charging completion message from the mobile terminal is received, the first controller interrupts power supplying for charging the battery in the mobile terminal to the first coil.

11. The wireless charging system of claim 10, wherein when the charging completion message is received, the first controller moves the first coil to a location that does not correspond to the second coil.

12. The wireless charging system of claim 8, wherein the detection unit is a pressure detection sensor.

13. The wireless charging system of claim 7, wherein the mobile terminal comprises:

a charging unit configured to charge the battery using the induced current; and

a second controller configured to determine whether electric charging of the battery is complete and transmit, if electric charging of the battery is complete, a charging completion message to the charging pad.

14. The wireless charging system of claim 13, wherein the mobile terminal further comprises a second storage unit configured to store second certification information representing that the mobile terminal is a chargeable device using the charging pad and the preset reference value.

15. An apparatus for charging a battery of a mobile terminal using electromagnetic induction, the apparatus comprising:

a charging pad comprising a first coil configured to generate a magnetic field when power is supplied, wherein the first coil is adapted to electromagnetically couple to a second coil included in a a mobile terminal such that an induction current is induced to the second coil in response to a magnetic field generated in the first coil,

wherein the charging pad is configured to determine a location of the mobile terminal and move the first coil to correspond to the location of the mobile terminal, and

wherein the charging pad is further configured to, when a charging efficiency is less than a preset reference value, receive from the mobile terminal a control signal requesting a location movement of the first coil, and move a location of the first coil according to the control signal.

16. The apparatus of claim 15, wherein the charging pad comprises:

a detection unit configured to detect a location of the mobile terminal;

a driver configured to enable the movement of the first coil to correspond to the location of the mobile terminal;

a first controller configured to determine whether the detected mobile terminal is a certified device and control, if the detected mobile terminal is a certified device, a wireless charging; and

a first storage unit configured to store first certification information for determining whether the mobile terminal is a chargeable device.

17. The apparatus of claim 16, wherein when the control signal requesting the location movement of the first coil is received from the mobile terminal, the first controller controls the driver to move the location of the first coil.

18. The apparatus of claim 16, wherein when a charging completion message from the mobile terminal is received, the first controller interrupts power supplying for charging the battery in the mobile terminal to the first coil.

19. The apparatus of claim 18, wherein when the charging completion message is received, the first controller moves the first coil to a location that does not correspond to the second coil.

20. The apparatus of claim 15, wherein the charging efficiency is determined at the mobile terminal.