WIRELESS POWER FEEDING SYSTEM AND WIRELESS POWER FEEDING METHOD

• US 20120025627A1
• Filed: 07/25/2011
• Published: 02/02/2012
• Est. Priority Date: 07/28/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: SHIONOIRI, Yutaka, KAMATA, Koichiro, SATO, Misako, MAEDA, Shuhei
• Granted Patent: US 8,836,170 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

An object is to provide a power feeding system and a power feeding method which are more convenient for a power feeding user at the power receiving end. An object is to provide a power feeding system and a power feeding method which also allow a power feeding provider (a company) which feeds power (at the power transmitting end) to supply power without waste. A power feeding device which wirelessly supplies power to a power receiver detects the position and the resonant frequency of the power receiver to be supplied with power, and controls the frequency of a power signal to be transmitted to the power receiver on the basis of the information.

An efficient power feeding service can be offered by transmitting a power signal to the power receiver at an optimum frequency for high power transmission efficiency.

Claims

1. A wireless power feeding system comprising:

a wireless power feeding device comprising;

a power feeding device transmission/reception circuit portion; and

a signal processing circuit portion having a resonant frequency detection function and a power transmission control function;

a wireless power receiver comprising;

a power receiver transmission/reception circuit portion;

a signal processing circuit portion; and

a power storage portion comprising a secondary battery,

wherein the wireless power feeding device is configured to;

receive a detection signal transmitted by the power receiver;

detect a resonant frequency of the power receiver based on the detection signal;

adjust a frequency of a power signal to be transmitted by the power feeding device to the power receiver, based on the resonant frequency of the power receiver; and

transmit the power signal to the power receiver; and

wherein the wireless power receiver is configured to;

transmit the detection signal to the power feeding device;

receive the power signal having a frequency adjusted to the resonant frequency of the wireless power receiver; and

store power of the power signal in the secondary battery of the power storage portion.

4. A wireless power feeding system according to claim 1, the wireless power receiver further comprising a voltage current detection portion,

wherein the wireless power receiver is further configured to transmit to the power feeding device a signal for requesting beginning or end of power feeding in accordance with a detected voltage, a detected current or detected current and voltage outputted from the secondary battery.

6. A wireless power feeding system according to claim 1, the wireless power receiver further comprising a memory,

wherein the wireless power receiver is further configured to transmit identification information stored in the memory to the power feeding device;

and

wherein the wireless power feeding device is further configured to receive the identification information.

9. A wireless power feeding system according to claim 1,

wherein the detection signal comprises a plurality of signals having different frequencies.

12. A wireless power feeding system according to claim 1, wherein the wireless power receiver is one of a portable electronic device, category comprising mobile phones, notebook personal computers, cameras including digital cameras or digital video cameras, digital photo frames, portable game machines, personal digital assistants, and electronic books, and a transportation means driven by an electric motor, category comprising automobiles, motorized bicycles including motor-assisted bicycles, aircrafts, ships, and railroad cars.

2. A wireless power receiver comprising:

a transmission/reception circuit portion, the transmission/reception circuit portion comprising;

an antenna circuit;

a rectifier circuit;

a demodulation circuit;

a modulation circuit;

an oscillator circuit; and

a power supply circuit;

a signal processing circuit portion; and

a power storage portion comprising a secondary battery,

wherein the wireless power receiver is configured to;

emit a detection signal apt to allow a power feeding device to detect a resonant frequency of the power receiver;

receive a power signal having a frequency adjusted to a resonant frequency of the wireless power receiver detected from the detection signal; and

store power transmitted by the power signal in the secondary battery of the power storage portion.

5. A wireless power receiver according to claim 2, further comprising a voltage current detection portion,

wherein the wireless power receiver is further configured to emit a signal for requesting beginning or end of power feeding in accordance with a detected voltage, a detected current or detected current and voltage outputted from the secondary battery.

7. A wireless power receiver according to claim 2, further comprising a memory,

wherein the wireless power receiver is further configured to emit identification information stored in the memory.

10. A wireless power receiver according to claim 2,

wherein the detection signal comprises a plurality of signals having different frequencies.

13. A wireless power receiver according to claim 2, wherein the wireless power receiver is one of a portable electronic device, category comprising mobile phones, notebook personal computers, cameras including digital cameras or digital video cameras, digital photo frames, portable game machines, personal digital assistants, and electronic books, and a transportation means driven by an electric motor, category comprising automobiles, motorized bicycles including motor-assisted bicycles, aircrafts, ships, and railroad cars.

3. A wireless power feeding device comprising:

a transmission/reception circuit portion, the transmission/reception circuit portion comprising;

an antenna circuit;

a rectifier circuit;

a demodulation circuit;

a modulation circuit;

an oscillator circuit; and

a power supply circuit;

a signal processing circuit portion having a resonant frequency detection function and a power transmission control function; and

a power supply portion,

wherein the wireless power feeding device is configured to;

receive a detection signal transmitted by a power receiver;

detect a resonant frequency of the power receiver based on the detection signal;

adjust a frequency of a power signal to be emitted by the power feeding device, based on the resonant frequency; and

emit the power signal.

8. A wireless power feeding device according to claim 3,

wherein the wireless power feeding device is further configured to receive identification information emitted by the power receiver.

11. A wireless power feeding device according to claim 3, wherein the detection signal comprises a plurality of signals having different frequencies.

14. A wireless power feeding method for a wireless power feeding system comprising the steps of:

transmission of a detection signal by a power receiver to a power feeding device;

reception of the detection signal by the power feeding device;

detection of a resonant frequency of the power receiver by the power feeding device, based on the detection signal;

frequency adjustment of a power signal to be transmitted from the power feeding device to the power receiver, based on the resonant frequency;

transmission of the power signal by the power feeding device to the power receiver;

reception of the power signal by the power receiver; and

storage of power transmitted by the power signal in a power storage portion of the power receiver.

17. A wireless power feeding method for a wireless power feeding system according to claim 14, further comprising the step of:

transmission of identification information from the power receiver to the power feeding device.

20. A wireless power feeding method for a wireless power feeding system according to claim 14, further comprising the steps of:

detection of voltage, current, or voltage and current outputted from a secondary battery of the power storage portion of the power receiver.

22. A wireless power feeding method for a wireless power feeding system according to claim 14,

wherein the detection signal comprises a plurality of signals having different frequencies.

15. A wireless power feeding method for a wireless power receiver comprising the steps of:

emission of a detection signal apt to allow a power feeding device to detect a resonant frequency of the power receiver by the power receiver;

reception of a power signal having a frequency adjusted to a resonant frequency of the power receiver; and

storage of power transmitted by the power signal in a power storage portion of the power receiver.

18. A wireless power feeding method for a wireless power receiver according to claim 15, further comprising the step of emission of identification information by the power receiver.

21. A wireless power feeding method for a wireless power receiver according to claim 15, further comprising the steps of:

detection of voltage, current, or voltage and current outputted from a secondary battery of the power storage portion of the power receiver.

23. A wireless power feeding method for a wireless power receiver according to claim 15,

wherein the detection signal comprises a plurality of signals having different frequencies.

16. A wireless power feeding method for a wireless power feeding device comprising the steps of:

reception of a detection signal emitted by a power receiver by the power feeding device;

detection of a resonant frequency by the power feeding device, based on the detection signal;

frequency adjustment of a power signal to be emitted by the power feeding device, based on the resonant frequency; and

emission of the power signal.

19. A wireless power feeding method for a wireless power feeding device according to claim 16, further comprising the step of reception of identification information by the power feeding device.

24. A wireless power feeding method for a wireless power feeding device according to claim 16,

wherein the detection signal comprises a plurality of signals having different frequencies.