Power Supply Device and Method for Detecting Presence of Foreign Object

• US 20150022014A1
• Filed: 07/08/2014
• Published: 01/22/2015
• Est. Priority Date: 07/22/2013
• Status: Abandoned Application

• Current Assignee: Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Original Assignee: Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Inventors: Tanabe, Hideki
• Application Number:
  US14/325,520
• Publication Number:
  US 20150022014A1
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/05 using capacitive coupling
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

The power supply device of the present invention is provided with: a power supply surface on which a power-supply object is placed; a plurality of electrodes arranged along the power supply surface; a capacitance-detecting unit for detecting the capacitance produced in each of the electrodes; and a control unit for scanning and driving the plurality of electrodes, identifying a capacitance distribution on the power supply surface on the basis of the capacitance produced in each of the electrodes as detected by the capacitance-detecting unit, determining the presence or absence of a foreign object on the power supply surface on the basis of the capacitance distribution, and performing a predetermined process. This makes it possible to detect with high accuracy the presence or absence of a foreign object on the power supply surface.

Claims

1. A power supply device, provided with:

a power supply surface on which a power-supply object is placed;

a plurality of electrodes arranged along the power supply surface;

a capacitance-detecting unit for detecting the capacitance produced in each of the electrodes; and

a control unit for scanning and driving the plurality of electrodes, identifying a capacitance distribution on the power supply surface on the basis of the capacitance produced in each of the electrodes as detected by the capacitance-detecting unit, determining the presence or absence of a foreign object on the power supply surface on the basis of the capacitance distribution, and performing a predetermined process.

2. The power supply device of claim 1, wherein the control unit determines the presence or absence of a foreign object on the power supply surface on the basis of the area and shape of a portion in which the value of the capacitance exceeds a predetermined value in the capacitance distribution for the power supply surface.

3. The power supply device of claim 1, wherein the control unit stops the supply of power to the power-supply object, as the predetermined process, in a case in which there is a foreign object on the power supply surface.

4. The power supply device of claim 1, wherein the control unit identifies a position of a foreign object when the foreign object is on the power supply surface, and stops the supply of power to the power-supply object, as the predetermined process, in a case in which the foreign object is positioned in the vicinity of the power-supply object.

5. The power supply device of claim 1, wherein the control unit issues a warning about the presence of a foreign object, as the predetermined process, in a case in which the foreign object is on the power supply surface.

6. The power supply device of claim 1, wherein the control unit scans and drives the plurality of electrodes on the basis of information indicating a change in capacitance of at least one of the electrodes and identifies the capacitance distribution on the power supply surface.

7. The power supply device of claim 1, wherein the plurality of electrodes are arranged so as to suppress an eddy current generated in the plurality of electrodes by a magnetic field generated during the supplying of power to the power-supply object.

8. The power supply device of claim 7, wherein each of the electrodes is comb-shaped.

9. A method for detecting a foreign object, having:

a step for scanning and driving a plurality of electrodes arranged along a power supply surface;

a step for acquiring a capacitance produced in each of the electrodes subjected to scanning and driving;

a step for identifying a capacitance distribution on the power supply surface on the basis of the acquired capacitance produced in each of the electrodes;

a step for determining the presence or absence of a foreign object on the power supply surface on the basis of the identified capacitance distribution; and

a step for performing a predetermined process on the basis of the presence or absence of the foreign object on the power supply surface.