Portable electronic device and capacitive charger therefor and associated methods

• US 20060176015A1
• Filed: 02/04/2005
• Published: 08/10/2006
• Est. Priority Date: 02/04/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Bersenev, Alexander I.
• Granted Patent: US 7,504,802 B2
• Time in Patent Office: Days
• US Class Current: 320/114
• CPC Class Codes: H02J 50/05 using capacitive coupling
• 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 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

An electronic apparatus includes a portable electronic device and a charger for capacitively charging the portable electronic device when the portable electronic device is temporarily placed adjacent the charger. The portable electronic device includes a housing, a battery carried by the housing, and at least one pair of device capacitive electrodes carried by the housing for charging the battery and defining a device conductive footprint. The charger includes a base having an area larger than the device conductive footprint, and an array of charger capacitive electrodes carried by the base. The charger further includes a charger controller for selectively driving the charger capacitive electrodes within the device conductive footprint with a charging signal sufficient to capacitively charge the battery of the portable electronic device and not driving charger capacitive electrodes outside the device conductive footprint.

Claims

1. An electronic apparatus comprising:

a portable electronic device and a charger for capacitively charging said portable electronic device when said portable electronic device is temporarily placed adjacent said charger;

said portable electronic device comprising a housing, a battery carried by the housing, and at least one pair of device capacitive electrodes carried by said housing for charging said battery and defining a device conductive footprint;

said charger comprising

a base having an area larger than the device conductive footprint and able to receive said portable electronic device thereon in a plurality of different positions,

an array of charger capacitive electrodes carried by said base, and

a charger controller for selectively driving said charger capacitive electrodes within the device conductive footprint with a charging signal sufficient to capacitively charge said battery of said portable electronic device and not driving charger capacitive electrodes outside the device conductive footprint with the charging signal when said portable electronic device is positioned on said charger to thereby capacitively charge said battery of said portable electronic device while reducing undesired electromagnetic interference (EMI).

2. The electronic apparatus according to claim 1 wherein said charger controller senses impedances of said charger capacitive electrodes to determine whether a respective charger capacitive electrode is within the device conductive footprint or not.

3. The electronic apparatus according to claim 2 wherein said charger controller sequentially drives said charger capacitive electrodes with a sensing signal to sense impedances thereof.

4. The electronic apparatus according to claim 3 wherein the charging signal has an amplitude at least one hundred times greater than an amplitude of the sensing signal.

5. The electronic apparatus according to claim 1 wherein said charger controller comprises:

a charging signal generator;

a switching circuit connected between said charging signal generator and said charger capacitive electrodes; and

a control circuit connected to said switching circuit.

6. The electronic apparatus according to claim 5 wherein said charger controller further comprises:

a buffer connected between said charging signal generator and said switching circuit; and

an impedance detector connected to said buffer and said control circuit.

7. The electronic apparatus according to claim 5 wherein said control circuit operates said charging signal generator at a reduced amplitude to serve as a signal generator for the sensing signal.

8. The electronic apparatus according to claim 1 wherein said charger controller and said portable electronic device also communicate via said charger capacitive electrodes.

9. A charger for capacitively charging a portable electronic device when the portable electronic device is temporarily placed adjacent the charger, the portable electronic device comprising a housing, a battery carried by the housing, and at least one pair of device capacitive electrodes carried by the housing for charging the battery and defining a device conductive footprint, the charger comprising:

a base having an area larger than the device conductive footprint and able to receive the portable electronic device thereon in a plurality of different positions;

an array of charger capacitive electrodes carried by said base; and

a charger controller for selectively driving said charger capacitive electrodes within the device conductive footprint with a charging signal sufficient to capacitively charge the battery of the portable electronic device and not driving charger capacitive electrodes outside the device conductive footprint with the charging signal when the portable electronic device is positioned on said charger to thereby capacitively charge the battery of the portable electronic device while reducing undesired electromagnetic interference (EMI).

10. The charger according to claim 9 wherein said charger controller senses impedances of said charger capacitive electrodes to determine whether a respective charger capacitive electrode is within the device conductive footprint or not.

11. The charger according to claim 10 wherein said charger controller sequentially drives said charger capacitive electrodes with a sensing signal to sense impedances thereof.

12. The charger according to claim 11 wherein the charging signal has an amplitude at least one hundred times greater than an amplitude of the sensing signal.

13. The charger according to claim 9 wherein said charger controller comprises:

a charging signal generator;

a switching circuit connected between said charging signal generator and said charger capacitive electrodes; and

a control circuit connected to said switching circuit.

14. The charger according to claim 13 wherein said charger controller further comprises:

a buffer connected between said charging signal generator and said switching circuit; and

an impedance detector connected to said buffer and said control circuit.

15. The charger according to claim 13 wherein said control circuit operates said charging signal generator at a reduced amplitude to serve as a signal generator for the sensing signal.

16. A charger for capacitively charging a battery in a portable electronic device when the portable electronic device is temporarily placed adjacent the charger, the charger comprising:

a base having an area larger than the portable electronic device and able to receive the portable electronic device thereon in a plurality of different positions;

an array of charger capacitive electrodes carried by said base; and

a charger controller for selectively driving said charger capacitive electrodes with a charging signal sufficient to capacitively charge the battery of the portable electronic device and not driving charger capacitive electrodes not covered by the portable electronic device with the charging signal when the portable electronic device is positioned on said charger.

17. The charger according to claim 16 wherein said charger controller sequentially drives said charger capacitive electrodes with a sensing signal to sense impedances thereof.

18. The charger according to claim 17 wherein the charging signal has an amplitude at least one hundred times greater than an amplitude of the sensing signal.

19. The charger according to claim 16 wherein said charger controller comprises:

a charging signal generator;

a switching circuit connected between said charging signal generator and said charger capacitive electrodes; and

a control circuit connected to said switching circuit.

20. The charger according to claim 19 wherein said charger controller further comprises:

a buffer connected between said charging signal generator and said switching circuit; and

an impedance detector connected to said buffer and said control circuit.

21. The charger according to claim 19 wherein said control circuit operates said charging signal generator at a reduced amplitude to serve as a signal generator for the sensing signal.

22. A method of capacitively charging a portable electronic device with a charger, the portable electronic device comprising a housing, a battery carried by the housing, and at least one pair of device capacitive electrodes carried by the housing for charging the battery and defining a device conductive footprint, and the charger comprising a base having an area larger than the device conductive footprint and able to receive the portable electronic device thereon in a plurality of different positions, an array of charger capacitive electrodes carried by the base, and a charger controller connected to the charger capacitive electrodes, the method comprising:

temporarily placing the portable electronic device adjacent the charger; and

selectively driving, via the charger controller, the charger capacitive electrodes within the device conductive footprint with a charging signal sufficient to capacitively charge the battery of the portable electronic device and not driving charger capacitive electrodes outside the device conductive footprint with the charging signal to thereby capacitively charge the battery of the portable electronic device while reducing undesired electromagnetic interference (EMI).

23. The method according to claim 22 further comprising sensing, via the charger controller, the impedances of the charger capacitive electrodes to determine whether a respective charger capacitive electrode is within the device conductive footprint or not.

24. The method according to claim 23 further comprising sequentially driving, via the charger controller, the charger capacitive electrodes with a sensing signal to sense impedances thereof.

25. The method according to claim 24 wherein the charging signal has an amplitude at least one hundred times greater than an amplitude of the sensing signal.