WIRELESS CHARGER WITH COMBINED ELECTRIC RADIATION SHIELDING AND CAPACITIVE SENSING FUNCTIONS

• US 20140197782A1
• Filed: 01/15/2013
• Published: 07/17/2014
• Est. Priority Date: 01/15/2013
• Status: Abandoned Application

• Current Assignee: Lite-On Technology Corporation
• Original Assignee: Lite-On It Corporation (Lite-On Technology Corporation)
• Inventors: GRAF, Stefan, WALDSCHMIDT, Andre, ROTH, Karsten, LINDENSTRUTH, Lars
• Application Number:
  US13/742,159
• Publication Number:
  US 20140197782A1
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: H04B 15/04 the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

A wireless charger with combined electric radiation shielding and capacitive sensing functions is provided. The wireless charger comprises a charging module, a capacitive sensor, and a control unit. The charging module comprises a first coil, a placing area, and a comb-shaped shielding located between the placing area and the first coil. The capacitive sensor is connected to the comb-shaped shielding to detect the capacitance varient between the comb-shaped shielding and the environment. When the wireless charger is in a standby mode, the comb-shaped shielding is for sensing capacitance. When the capacitance varient exceeds a predefined threshold and an electronic device for wireless charging is placed on the placing area, the control unit switches the wireless charger to a charging mode and the comb-shaped shielding is for electric radiation shielding.

Claims

1. A wireless charger for charging an electronic device with a second coil, comprising:

a charging module, comprising a first coil electromagnetically coupled to the second coil, a placing area for the electronic device to be placed on opposite to the first coil, and a comb-shaped shielding located between the placing area and the first coil;

a capacitive sensor, which is connected to the comb-shaped shielding to detect the capacitance varient between the comb-shaped shielding and the environment; and

a control unit, which is connected to the comb-shaped shielding and the capacitive sensor and records the capacitance varient;

wherein, when the capacitance varient exceeds a predefined threshold, the control unit sends a ping signal to the electronic device, and if the electronic device responds, the control unit switches the charging module from a standby mode to a charging mode to wireless charge the electronic device and switches the comb-shaped shielding to be connected to a ground.

2. The wireless charger of claim 1, wherein the control unit further comprises a switch, which is electrically connected between the ground and the comb-shaped shielding.

3. The wireless charger of claim 2, wherein the switch is a transistor.

4. The wireless charger of claim 1, wherein the ping signal is sending from the control unit via the first coil.

5. The wireless charger of claim 1, wherein the comb-shaped shielding comprises a plurality of parallel segments.

6. The wireless charger of claim 1, wherein the comb-shaped shielding is printed as a circuit path on a PCB board.

7. The wireless charger of claim 1, wherein at least two comb-shaped shieldings are used, positioned with different directions against each other and located in different layers of the wireless charger.

8. The wireless charger of claim 1, wherein the comb-shaped shielding is used as a capacitive sensor electrode when the wireless charger is in the stanby mode.

9. A method for combing electric radiation shielding and capacitive sensing functions to a wireless charger, comprising:

(a) detecting a capacitance varient between a comb-shaped shielding of the wireless charger and the environment via a capacitive sensor connected to the comb-shaped shielding in a standby mode;

(b) transmitting a ping signal to confirm an electronic device is to be charged when the capacitance varient exceeds a predefined threshold by a controller;

(c) switching the comb-shaped shielding to be connected to a ground and powering on the wireless charger to perform wireless charging when a response to the ping signal is received in a charging mode; and

(d) switching the wireless charger back to the standby mode when the capacitance varient is under the predefined threshold.

10. The method of claim 9, wherein the wireless charger is connected to a controller to record the capacitance varient and to perform the switch between the standby mode and the charging mode.

11. The method of claim 9, wherein the capacitive sensor is a capacitive sensor integrated circuit.

12. The method of claim 9, wherein the control unit further comprises a switch, which is electrically connected between the ground and the comb-shaped shielding.

13. The method of claim 12, wherein the switch is a transistor.

14. The method of claim 9, wherein the comb-shaped shielding comprises a plurality of parallel segments.

15. The methof of claim 9, wherein the comb-shaped shielding is printed as a circuit path on a PCB board.

16. The method of claim 9, wherein at least two comb-shaped shieldings are used, positioned with different directions against each other and located in different layers of the wireless charger.