WIRELESS POWER SUPPLY SYSTEM, WIRELESS POWER TRANSMITTING DEVICE, AND WIRELESS POWER RECEIVING DEVICE

• US 20120001485A1
• Filed: 09/13/2011
• Published: 01/05/2012
• Est. Priority Date: 03/30/2009
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: UCHIDA, Akiyoshi
• Granted Patent: US 8,933,583 B2
• Time in Patent Office: Days
• US Class Current: 307/11
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• 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 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

A wireless power supply system includes: a wireless power transmitting device configured to include a variable resonant circuit having a variable-controllable resonant frequency characteristic, and to transmit electric power wirelessly via the variable resonant circuit; a power transmission control unit configured to variably control the resonant frequency characteristic of the variable resonant circuit; and a plurality of wireless power receiving devices configured to include respective unique resonant circuits having respective unique resonant frequency characteristics which are different to each other, and to wirelessly receive power from the wireless power transmitting device by a magnetic field resonance mode arising as a result of the unique resonant circuit tuning to a resonant frequency of the variable resonant circuit.

Claims

1. A wireless power supply system, comprising:

a wireless power transmitting device configured to include a variable resonant circuit having a variable-controllable resonant frequency characteristic, and to transmit electric power wirelessly via the variable resonant circuit;

a power transmission control unit configured to variably control the resonant frequency characteristic of the variable resonant circuit; and

a plurality of wireless power receiving devices configured to include respective unique resonant circuits having respective unique resonant frequency characteristics which are different to each other, and to wirelessly receive electric power from the wireless power transmitting device by a magnetic field resonance mode arising as a result of the unique resonant circuit tuning to a resonant frequency of the variable resonant circuit.

2. The wireless power supply system according to claim 1, wherein:

the variable resonant circuit is configured to include a power transmitting coil and a plurality of capacitors of different capacitances which are selectively connected to the power transmitting coil; and

the power transmission control unit is configured to selectively control connection of the plurality of capacitors to the power transmitting coil.

3. The wireless power supply system according to claim 2, wherein each of the unique resonant circuits is configured to include a capacitor, capacitance of the respective capacitors being mutually different, and a power receiving coil connected to the capacitor.

4. A wireless power supply system, comprising:

a wireless power transmitting device configured to include a power transmitting resonant circuit having a predetermined resonant frequency characteristic, and to transmit electric power wirelessly via the power transmitting resonant circuit;

a plurality of wireless power receiving devices configured to include respective power receiving resonant circuits having a same resonant frequency characteristic as the power transmitting resonant circuit, and to wirelessly receive electric power from the wireless power transmitting device by a magnetic field resonance mode arising as a result of the power receiving resonant circuit tuning to a resonant frequency of the power transmitting resonant circuit; and

a power receiving control unit configured to perform on and off control of a circuit connection state of the power receiving resonant circuit for each of the wireless power receiving devices.

5. The wireless power supply system according to claim 4, wherein:

each of the wireless power receiving devices is configured to include;

a battery configured to store electric power received via the power receiving resonant circuit, and

a communication unit configured to exchange information regarding a storage status of the battery between the wireless power transmitting device and the plurality of wireless power receiving devices;

the wireless power transmitting device is configured to start transmission of electric power in accordance with a command from the communication unit; and

the power receiving control unit is configured to perform on and off control of the circuit connection state of the power receiving resonant circuit for each of the wireless power receiving devices in accordance with a command from the communication unit.

6. The wireless power supply system according to claim 4, wherein:

each of the wireless power receiving devices is configured to include a battery which is configured to store electric power received via the power receiving resonant circuit;

the power receiving control unit is configured to perform on and off control of the circuit connection state of the power receiving resonant circuit in accordance with a storage status of the battery for each of the wireless power receiving devices.

7. A wireless power supply system, comprising:

a wireless power transmitting unit configured to include a variable resonant circuit including a power transmitting coil capable of transmitting electric power as magnetic field energy, the variable resonant circuit having a characteristic of resonating at a first frequency and a second frequency, and to transmit magnetic field energy from the power transmitting coil in a resonant state;

a power transmission control unit configured to change a resonance characteristic of the variable resonant circuit by using the first frequency and the second frequency;

a first wireless power receiving unit configured to include a first power receiving resonant circuit including a first power receiving coil capable of taking in magnetic field energy, the first power receiving resonant circuit having a characteristic of resonating at the first frequency, and to receive magnetic field energy as electric power by means of the first power receiving coil which resonates with the power transmitting coil and enters a resonant state; and

a second wireless power receiving unit configured to include a second power receiving resonant circuit including a second power receiving coil capable of taking in magnetic field energy, the second power receiving resonant circuit having a characteristic of resonating at the second frequency, and to receive magnetic field energy as electric power by means of the second power receiving coil which resonates with the power transmitting coil and enters a resonant state.

8. A wireless power supply system, comprising:

a wireless power transmitting unit configured to include a power transmitting resonant circuit including a power transmitting coil capable of transmitting electric power as magnetic field energy, the power transmitting resonant circuit having a characteristic of resonating at a power transmission frequency, and to transmit magnetic field energy from the power transmitting coil in a resonant state;

a plurality of wireless power receiving units configured to include a power receiving resonant circuit including a power receiving coil capable of taking in magnetic field energy, the power receiving resonant circuit having a characteristic of resonating at the power transmission frequency, and to receive magnetic field energy as electric power by means of the power receiving coil which resonates with the power transmitting coil and enters a resonant state; and

a power receiving control unit configured to control so as to degrade the resonance characteristic of the power receiving resonant circuit for each of the wireless power receiving units.

9. A wireless power transmitting device, comprising:

a variable resonant circuit having a variable-controllable resonant frequency characteristic; and

a power transmission control unit configured to variably control the resonant frequency characteristic of the variable resonant circuit, and to wirelessly transmit electric power via the variable resonant circuit by causing the resonant frequency to tune to a resonant frequency on a power receiving side to generate a magnetic field resonance mode.

10. A wireless power receiving device, comprising:

a power receiving resonant circuit configured to have a resonant frequency characteristic which corresponds to a power transmitting side, and to wirelessly receive electric power from the power transmitting side;

a battery configure to store electric power which is received via the power receiving resonant circuit; and

a power receiving control unit configured to perform on and off control of a circuit connection state of the power receiving resonant circuit in accordance with a storage status of the battery, and to cause electric power to be wirelessly received from the power transmitting side by placing the circuit connection state in an “

on”

state to cause a resonant frequency of the power receiving resonant circuit to tune to a resonant frequency of a power transmitting side to generate a magnetic field resonance mode.