Contactless power transferring coil unit, mobile terminal, power transmitting apparatus, and contactless power transferring system

• US 20080297107A1
• Filed: 05/28/2008
• Published: 12/04/2008
• Est. Priority Date: 05/28/2007
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group), Sony Ericsson Mobile Communications Japan Incorporated (Sony Group Corp.)
• Original Assignee: Seiko Epson Corporation (Seiko Group), Sony Ericsson Mobile Communications Japan Incorporated (Sony Group Corp.)
• Inventors: Suzuki, Katsuya, Yamazaki, Manabu, Onishi, Kota, Jin, Mikimoto, Kato, Hiroshi, Kamijo, Takahiro, Kondo, Yoichiro, Suzuki, Kuniharu, Yoda, Kentaro, Sogabe, Haruhiko
• Granted Patent: US 8,159,182 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H01F 27/2871 Pancake coils
• 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 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source

Abstract

A contactless power transferring coil unit is provided. The contactless power transferring coil unit includes a flat coil, a magnetic film, and a leaking flux detecting coil. The flat coil is formed by winding a conductive wire into a spiral on a substantially flat plane. The magnetic film is disposed so as to cover one entire flat surface of the flat coil. The leaking flux detecting coil is disposed in a periphery outside an outer edge of the flat coil and the magnetic film and detects leaking magnetic flux from the flat coil.

Claims

1. A contactless power transferring coil unit comprising:

a flat coil formed by winding a conductive wire into a spiral on a substantially flat plane;

a magnetic film disposed so as to cover one entire flat surface of the flat coil; and

a leaking flux detecting coil that is disposed in a periphery outside an outer edge of the flat coil and the magnetic film and detects leaking magnetic flux from the flat coil.

2. A contactless power transferring coil unit according to claim 1, wherein

the leaking flux detecting coil is formed of at least one winding of a conductive wire and has a larger diameter than the flat coil and the magnetic film.

3. A contactless power transferring coil unit according to claim 1, wherein

the leaking flux detecting coil is formed of a plurality of small flat coils that are formed by winding a conductive wire into spirals and are disposed in a periphery outside an outer edge of the flat coil and the magnetic film.

4. A contactless power transferring coil unit according to claim 3, wherein

the plurality of small flat coils are disposed in at least four directions on X and Y axes relative to a center axis of the flat coil.

5. A mobile terminal comprising:

a secondary cell;

a contactless power transferring coil unit including a flat coil formed by winding a conductive wire into a spiral on a substantially flat plane, a magnetic film disposed so as to cover one entire flat surface of the flat coil, and a leaking flux detecting coil that is disposed in a periphery outside an outer edge of the flat coil and the magnetic film and detects leaking magnetic flux from the flat coil, the contactless power transferring coil unit using electromagnetic induction between the flat coil and a coil provided in a power transmitting apparatus for transmitting power according to a contactless power transferring method to receive power transmitted from the power transmitting apparatus according to the contactless power transferring method;

a charging control circuit that controls charging of the secondary cell with the power received via the flat coil of the contactless power transferring coil unit; and

a signal transmitting unit that transmits a signal, in accordance with leaking magnetic flux detected by the leaking flux detecting coil of the contactless power transferring coil unit, to the power transmitting apparatus.

6. A mobile terminal according to claim 5, wherein

the leaking flux detecting coil is formed of at least one winding of a conductive wire and has a larger diameter than the flat coil and the magnetic film.

7. A mobile terminal according to claim 5, wherein

the leaking flux detecting coil is formed of a plurality of small flat coils that are formed by winding a conductive wire into spirals and are disposed in a periphery outside an outer edge of the flat coil and the magnetic film.

8. A mobile terminal according to claim 7, wherein

the plurality of small flat coils are disposed in at least four directions on X and Y axes relative to a center axis of the flat coil.

9. A power transmitting apparatus comprising:

a terminal mount on which a predetermined mobile terminal that includes a secondary cell is mounted;

a contactless power transferring coil that includes a flat coil formed by winding a conductive wire into a spiral on a substantially flat plane and uses electromagnetic induction between the flat coil and a coil installed in the predetermined mobile terminal to carry out contactless transfer of power for charging the secondary cell of the mobile terminal;

a signal receiving unit that receives, from the mobile terminal, a signal in accordance with leaking magnetic flux of the coil of the mobile terminal; and

a power transfer control unit that controls transfer of power from the flat coil of the contactless power transferring coil based on the signal in accordance with the leaking magnetic flux received by the signal receiving unit.

10. A power transmitting apparatus according to claim 9, wherein

the power transfer control unit controls the transfer of power by changing a resonant frequency of the flat coil of the contactless power transferring coil based on the signal in accordance with the leaking magnetic flux received by the signal receiving unit.

11. A power transmitting apparatus according to claim 9, wherein

the power transfer control unit controls the transfer of power by changing a resonant voltage of the flat coil of the contactless power transferring coil based on the signal in accordance with the leaking magnetic flux received by the signal receiving unit.

12. A power transmitting apparatus according to claim 9, wherein

the power transfer control unit controls the transfer of power by having power intermittently transmitted from the flat coil of the contactless power transferring coil, based on the signal in accordance with the leaking magnetic flux received by the signal receiving unit.

13. A contactless power transferring system comprising:

a mobile terminal including a contactless power transferring coil that is a secondary side during contactless power transferring and a leaking flux detecting coil that detects leaking magnetic flux from the secondary-side contactless power transferring coil; and

a power transmitting apparatus including a contactless power transferring coil that is a primary side during contactless power transferring, the power transmitting apparatus transferring power to the mobile terminal using electromagnetic induction between the primary-side contactless power transferring coil and the secondary-side contactless power transferring coil of the mobile terminal,

wherein the mobile terminal feeds back a signal in accordance with the leaking magnetic flux detected by the leaking flux detecting coil to the power transmitting apparatus, and

wherein the power transmitting apparatus controls transfer of power from the primary-side contactless power transferring coil based on the signal in accordance with the leaking magnetic flux fed back from the mobile terminal.

14. A contactless power transferring system according to claim 13, wherein

the power transmitting apparatus controls transfer of power by changing a resonant frequency of the primary-side contactless power transferring coil, based on a signal in accordance with the leaking magnetic flux fed back from the mobile terminal.

15. A contactless power transferring system according to claim 13, wherein

the power transmitting apparatus controls transfer of power by changing a resonant voltage of the primary-side contactless power transferring coil, based on a signal in accordance with the leaking magnetic flux fed back from the mobile terminal.

16. A contactless power transferring system according to claim 13, wherein

the power transmitting apparatus controls transfer of power by having power intermittently transmitted from the flat coil of the contactless power transferring coil, based on a signal in accordance with the leaking magnetic flux fed back from the mobile terminal.