Wireless power transmitting device and wireless power transmission system having a variable distance between a feeding surface and a power transmitting coil

• US 9,130,386 B2
• Filed: 01/25/2012
• Issued: 09/08/2015
• Est. Priority Date: 02/17/2011
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kawano, Hiroyasu, Matsui, Kiyoto, Taguchi, Masakazu, Shimokawa, Satoshi, Uchida, Akiyoshi
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): SHIAO, DAVID A
• Application Number:
  US13/357,905
• Publication Number:
  US 20120212069A1
• Time in Patent Office: 1,322 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• 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: H02J 7/0042 characterised by the mechanical construction

Abstract

A wireless power transmitting device includes a housing configured to have a feeding surface on which a power receiving device is to be placed; a power transmitting coil disposed inside the housing and configured to have a central axis that intersects with the feeding surface; and an alternating-current power supply configured to supply power to the power transmitting coil, wherein the feeding surface has raised and recessed portions in an area corresponding to a region inside an outer region of the power transmitting coil.

Claims

1. A wireless power transmitting device of magnetic field resonance type, comprising:

a housing configured to have a feeding surface on which a power receiving device is to be placed;

a power transmitting coil disposed inside the housing and configured to have a central axis that intersects with the feeding surface; and

an alternating-current power supply configured to supply power to the power transmitting coil,

wherein the housing is further configured so as to change a distance between the feeding surface and the power transmitting coil according to an amount of power at a horizontal position of the power transmitting coil,

wherein the feeding surface has raised and recessed portions by which a predetermined power is obtained from the power transmitting coil regardless of a point where the power receiving device is placed, the raised and recessed portions being disposed in an area directly above a region inside an outer region of the power transmitting coil, and

wherein the raised and recessed portions are designed based on a curve formed by connecting points at which the predetermined power is obtained.

2. The wireless power transmitting device according to claim 1, wherein the power transmitting coil includes

a primary coil to which an alternating current is supplied from the alternating-current power supply, and

a secondary coil configured to form a resonant circuit and magnetically connected to the primary coil.

3. The wireless power transmitting device according to claim 1, wherein the power transmitting coil is a planar spiral coil.

4. The wireless power transmitting device according to claim 1, wherein- a raised portion of the raised and recessed portions is located above coil wires of the power transmitting coil.

5. The wireless power transmitting device according to claim 1 , wherein the feeding surface has an inclined portion located above coil wires of the power transmitting coil and inclined downward toward the outside of the transmitting coil.

6. The wireless power transmitting device according to claim 1, wherein the points are determined based on a relationship between received power and distance between the power transmitting coil and the power receiving coil.

7. A wireless power transmission system of magnetic field resonance type, comprising:

a power transmitting device including

a housing configured to have a feeding surface on which a power receiving device is to be placed,

an alternating-current power supply, and

a power transmitting coil to which power is supplied from the alternating-current power supply;

a power receiving device configured to be placed on the feeding surface of the power transmitting device, the power receiving device including

a power receiving coil configured to resonate with a magnetic field produced by the power transmitting coil of the power transmitting device,

wherein the housing is further configured so as to change a distance between the feeding surface and the power transmitting coil according to an amount of power at a horizontal position of the power transmitting coil,

wherein the feeding surface has raised and recessed portions by which a predetermined power is obtained from the power transmitting coil regardless of a point where the power receiving device is placed, the raised and recessed portions being disposed in an area directly above a region inside an outer region of the power transmitting coil, and

wherein the raised and recessed portions are designed based on a curve formed by connecting points at which the predetermined power is obtained.

8. The wireless power transmission system according to claim 7, wherein the power transmitting coil is larger in diameter than the power receiving coil.

9. The wireless power transmission system according to claim 7, wherein the power transmitting coil includes

a primary coil to which power is supplied from the alternating-current power supply, and

a secondary coil configured to form a resonant circuit and magnetically connected to the primary coil;

and

the power receiving coil includes

a third coil configured to form a resonant circuit that resonates with a magnetic field produced by the secondary coil, and

a fourth coil magnetically connected to the third coil.

10. The wireless power transmission system according to claim 7, wherein at least one of the power transmitting device and the power receiving device includes a vibrator that generates vibration when the power receiving device is placed on the feeding surface of the power transmitting device.

11. The wireless power transmission system according to claim 7, wherein the power transmitting coil is a planar spiral coil.

12. The wireless power transmission system according to claim 7, wherein a raised portion of the raised and recessed portions is located above coil wires of the power transmitting coil.

13. The wireless power transmission system according to claim 7, wherein the feeding surface has an inclined portion located above coil wires of the power transmitting coil and inclined downward toward the outside of the transmitting coil.