POWER FEED DEVICE, POWER RECEIVING DEVICE, AND WIRELESS POWER FEED SYSTEM

• US 20110169337A1
• Filed: 12/23/2010
• Published: 07/14/2011
• Est. Priority Date: 01/08/2010
• Status: Abandoned Application

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kozakai, Osamu
• Application Number:
  US12/977,264
• Publication Number:
  US 20110169337A1
• Time in Patent Office: Days
• US Class Current: 307/104
• 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 50/12 of the resonant type

Abstract

A power feed device includes: a power generator configured to generate power that should be fed; a power feed element configured to be formed of a coil fed with power generated by the power generator; a resonance element configured to be coupled to the power feed element by electromagnetic induction; and a variable matching unit configured to include a function for impedance matching at a point of feed of the power to the power feed element, wherein a diameter of the power feed element is changeable, and the variable matching unit is capable of changing the diameter of the power feed element.

Claims

1. A power feed device comprising:

a power generator configured to generate power that should be fed;

a power feed element configured to be formed of a coil fed with power generated by the power generator;

a resonance element configured to be coupled to the power feed element by electromagnetic induction; and

a variable matching unit configured to include a function for impedance matching at a point of feed of the power to the power feed element, wherein

a diameter of the power feed element is changeable, and

the variable matching unit is capable of changing the diameter of the power feed element.

2. The power feed device according to claim 1, wherein

the power feed element and the variable matching unit include:

a front end unit that feeds power generated by the power generator to the power feed element;

a backbone line part whose one end is connected to the front end unit;

a plurality of coil parts that have diameters different from each other and each have one end connected to the backbone line part; and

a switch unit that selectively connects the other end of the plurality of coil parts to the front end unit.

3. The power feed device according to claim 1, further comprising:

a power detector configured to detect a state of power to be transmitted; and

a control unit configured to instruct the variable matching unit to set the diameter of the power feed element depending on a detection result by the power detector.

4. The power feed device according to claim 3, wherein

the control unit carries out control in such a manner that the diameter of the power feed element becomes larger when distance between the resonance element and a resonance element on a power receiving side is shorter and the diameter of the power feed element becomes smaller when the distance is longer.

5. A power receiving device comprising:

a resonance element configured to receive transmitted power based on a magnetic field resonance relationship;

a power feed element configured to be formed of a coil that is coupled to the resonance element by electromagnetic induction and is fed with received power;

a resonance element configured to be coupled to the power feed element by electromagnetic induction; and

a variable matching unit configured to include a function for impedance matching at a connecting part between the power and a load of the power feed element, wherein

a diameter of the power feed element is changeable, and

the variable matching unit is capable of changing the diameter of the power feed element.

6. The power receiving device according to claim 5, wherein

the power feed element and the variable matching unit include:

a front end unit that receives power received by the power feed element;

a backbone line part whose one end is connected to the front end unit;

a plurality of coil parts that have diameters different from each other and each have one end connected to the backbone line part; and

a switch unit that selectively connects the other end of the plurality of coil parts to the front end unit.

7. The power receiving device according to claim 5, further comprising:

a power detector configured to detect a state of received power; and

a control unit configured to instruct the variable matching unit to set the diameter of the power feed element depending on a detection result by the power detector.

8. The power receiving device according to claim 7, wherein

the control unit carries out control in such a manner that the diameter of the power feed element becomes larger when distance between the resonance element and a resonance element on a power transmitting side is shorter and the diameter of the power feed element becomes smaller when the distance is longer.

9. A wireless power feed system comprising:

a power feed device; and

a power receiving device configured to receive power transmitted from the power feed device based on a magnetic field resonance relationship, wherein

the power feed device includes

a power generator to generate power that should be fed,

a power feed element formed of a coil fed with power generated by the power generator,

a resonance element coupled to the power feed element by electromagnetic induction, and

a variable matching unit including a function for impedance matching at a point of feed of the power to the power feed element,

a diameter of the power feed element is changeable,

the variable matching unit is capable of changing the diameter of the power feed element,

the power receiving device includes

a resonance element that receives power transmitted from the power feed device based on a magnetic field resonance relationship,

a power feed element formed of a coil that is coupled to the resonance element by electromagnetic induction and is fed with received power,

a resonance element coupled to the power feed element by electromagnetic induction, and

a variable matching unit including a function for impedance matching at a connecting part between the power and a load of the power feed element,

a diameter of the power feed element is changeable, and

the variable matching unit is capable of changing the diameter of the power feed element.

10. The wireless power feed system according to claim 9, wherein

the power feed element and the variable matching unit in the power feed device include:

a front end unit that feeds power generated by the power generator to the power feed element;

a backbone line part whose one end is connected to the front end unit;

a plurality of coil parts that have diameters different from each other and each have one end connected to the backbone line part; and

a switch unit that selectively connects the other end of the plurality of coil parts to the front end unit.

11. The wireless power feed system according to claim 9, wherein

the power feed element and the variable matching unit in the power receiving device include:

a front end unit that receives power received by the power feed element;

a backbone line part whose one end is connected to the front end unit;

a plurality of coil parts that have diameters different from each other and each have one end connected to the backbone line part; and

a switch unit that selectively connects the other end of the plurality of coil parts to the front end unit.

12. The wireless power feed system according to claim 9, wherein

at least one of the power feed device and the power receiving device includes:

a power detector to detect a state of power; and

a control unit to instruct the variable matching unit to set the diameter of the power feed element depending on a detection result by the power detector.

13. The wireless power feed system according to claim 12, wherein

the control unit carries out control in such a manner that the diameter of the power feed element becomes larger when distance between the resonance element in the power feed device and the resonance element in the power receiving device is shorter and the diameter of the power feed element becomes smaller when the distance is longer.

14. The wireless power feed system according to claim 12, wherein

the control unit is disposed in the power feed device and the power receiving device, and

the control unit in the power feed device and the control unit in the power receiving device are capable of wirelessly giving and receiving information to and from each other.