SYSTEM AND METHOD FOR EFFICIENT WIRELESS POWER TRANSFER TO DEVICES LOCATED ON AND OUTSIDE A CHARGING BASE

• US 20130270923A1
• Filed: 06/07/2013
• Published: 10/17/2013
• Est. Priority Date: 04/21/2008
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Widmer, Hanspeter, Cook, Nigel P., Sieber, Lukas
• Granted Patent: US 9,450,456 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence

Abstract

A wireless power transmission system and method for transmitting power from a charging base to receivers located both on and outside the charging base. The system utilizes wireless power transmission of a transmitter with a wound transmit coil.

Claims

1-26. -26. (canceled)

27. An apparatus configured to transmit power via a magnetic field, the apparatus comprising:

an antenna circuit configured to inductively transmit power via the magnetic field at a magnetic field strength level sufficient to charge or power a receiver device;

a proximity detector configured to detect a proximity of a presence of a living being within a region of the magnetic field in which power is inductively transmitted at the magnetic field strength level; and

a controller configured to adjust the magnetic field strength level in response to detecting the presence of the living being within the region of the magnetic field.

28. The apparatus of claim 27, further comprising an input mechanism configured to receive manual input from the living being, the input mechanism configured to activate the proximity detector in response to receiving the manual input.

29. The apparatus of claim 27, further comprising a driver circuit configured to drive the antenna circuit at a frequency substantially equal to a resonant frequency of the antenna circuit, and wherein the frequency is substantially equal to a resonant frequency of a receive antenna circuit of the receiver device.

30. The apparatus of claim 27, wherein the proximity detector comprises an infrared sensor.

31. The apparatus of claim 27, wherein the controller is configured to reduce the magnetic field strength level to at least one of a lower magnetic field strength level or substantially zero.

32. The apparatus of claim 31, wherein the lower magnetic field strength level corresponds to a level configured to avoid biological harm to the living being.

33. The apparatus of claim 27, wherein the region corresponds to a near-field of the antenna circuit.

34. A method of transmitting power via a magnetic field, the method comprising:

inductively transmitting power via the magnetic field at a magnetic field strength level sufficient to charge or power a receiver device;

detecting a proximity, via a proximity detector, of a presence of a living being within a region of the magnetic field in which power is inductively transmitted at the magnetic field strength level; and

adjusting the magnetic field strength level inductively transmitted via the transmitting means in response to detecting the presence of the living being within the region of the magnetic field.

35. The method of claim 34, further comprising receiving manual input from the living being via an input mechanism and activating the proximity detector in response to receiving the manual input.

36. The method of claim 34, wherein the proximity detector comprises an infrared sensor.

37. The method of claim 34, wherein adjusting the magnetic field strength level comprises reducing the magnetic field strength level to at least one of a lower magnetic field strength level or substantially zero.

38. The method of claim 37, wherein the lower magnetic field strength level corresponds to a level configured to avoid biological harm to the living being.

39. An apparatus configured to transmit power via a magnetic field, the apparatus comprising:

means for inductively transmitting power via the magnetic field at a magnetic field strength level sufficient to charge or power a receiver device;

means for detecting a proximity of a presence of a living being within a region of the magnetic field in which power is inductively transmitted at the magnetic field strength level; and

means for adjusting the magnetic field strength level inductively transmitted via the transmitting means in response to detecting the presence of the living being within the region of the magnetic field.

40. The apparatus of claim 39, further comprising means for receiving manual input from the living being and means for activating the means for detecting in response to receiving the manual input.

41. The apparatus of claim 39, wherein the means for detecting the proximity of the living being comprises an infrared sensor.

42. The apparatus of claim 39, wherein the means for adjusting the magnetic field strength level comprises means for reducing the magnetic field strength level to at least one of a lower magnetic field strength level or substantially zero.