WIRELESS POWER FEEDING SYSTEM AND WIRELESS POWER FEEDING METHOD

• US 20120025611A1
• Filed: 07/25/2011
• Published: 02/02/2012
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KAMATA, Koichiro, SATO, Misako, MAEDA, Shuhei
• Granted Patent: US 8,901,777 B2
• Time in Patent Office: Days
• US Class Current: 307/43
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A power feeding device which wirelessly supplies power to a power receiver receives a position and resonant frequency detection signal from the power receiver, detects the position and the resonant frequency of the power receiver, and controls the frequency of a power signal to be transmitted to the power receiver on the basis of the information. As the power signal for power transmission, two signals having different frequencies, which are generated using a mixer by mixing a base carrier (a first signal) with a conversion carrier (a second signal) generated on the basis of the resonant frequency, are used.

Claims

1. A semiconductor device comprising:

an antenna circuit configured to receive a first electromagnetic wave from a power receiver;

a signal processing circuit configured to detect a resonant frequency of the power receiver from a signal transmitted via the first electromagnetic wave,

a first oscillator circuit configured to generate a first signal;

a second oscillator circuit configured to generate a second signal in accordance with the distance and the resonant frequency of the power receiver; and

a mixer configured to mix the first signal with the second signal,

wherein the antenna circuit is configured to transmit a signal generated by the mixer to the power receiver via a second electromagnetic wave.

2. The semiconductor device according to claim 1, further comprising a first power supply circuit configured to supply power to the first oscillator circuit and a second power supply circuit configured to supply power to the second oscillator circuit.

3. The semiconductor device according to claim 1,

wherein power is transmitted to the power receiver via the second electromagnetic wave, and

wherein the signal processing circuit is configured to control power to be transmitted to the power receiver.

4. A wireless power feeding system comprising:

a power feeding device; and

a power receiver including a power receiving device portion,

wherein the power feeding device comprises;

a transmission/reception circuit portion for the power feeding device, configured to transmit and receive an electromagnetic wave;

a signal processing circuit portion for the power feeding device, configured to process an electrical signal of the electromagnetic wave to be transmitted and received by the transmission/reception circuit portion for the power feeding device; and

a power supply portion configured to supply power to be transmitted to the power receiver,

wherein the signal processing circuit portion for the power feeding device has a position and resonant frequency detection function to detect a position and a resonant frequency of the power receiver, and a power transmission control function to control power to be transmitted to the power receiver,

wherein the transmission/reception circuit portion for the power feeding device comprises an antenna circuit, a rectifier circuit, a mixer, a demodulation circuit, a first oscillator circuit, a first power supply circuit, a second oscillator circuit, and a second power supply circuit,

wherein the power receiving device portion comprises;

a transmission/reception circuit portion for the power receiving device portion, configured to transmit and receive an electromagnetic wave;

a signal processing circuit portion for the power receiving device portion, configured to process an electrical signal of the electromagnetic wave to be transmitted and received by the transmission/reception circuit portion for the power receiving device portion; and

a power storage portion including a secondary battery, configured to store power transmitted from the power feeding device and supply power to be consumed by a power load portion,

wherein the signal processing circuit portion for the power receiving device portion has a power reception control function to control power to be received from the power feeding device, and

wherein the mixer mixes a first signal generated by the first power supply circuit and the first oscillator circuit with a second signal generated by the second power supply circuit and the second oscillator circuit.

5. The wireless power feeding system according to claim 4, wherein the transmission/reception circuit portion for the power receiving device portion comprises an antenna circuit, a rectifier circuit, a modulation circuit, a demodulation circuit, an oscillator circuit, and a power supply circuit.

6. The wireless power feeding system according to claim 4,

wherein the power receiver comprises a memory portion configured to store identification information to be read by the signal processing circuit portion for the power receiving device portion, and

wherein the signal processing circuit portion for the power feeding device has an identification function to identify the identification information.

7. A wireless power feeding system comprising:

a power feeding device; and

a power receiver including a power receiving device portion,

wherein the power feeding device comprises;

a transmission/reception circuit portion for the power feeding device, configured to transmit and receive an electromagnetic wave;

a signal processing circuit portion for the power feeding device, configured to process an electrical signal of the electromagnetic wave to be transmitted and received by the transmission/reception circuit portion for the power feeding device; and

a power supply portion configured to supply power to be transmitted to the power receiver,

wherein the signal processing circuit portion for the power feeding device has a position and resonant frequency detection function to detect a position and a resonant frequency of the power receiver and a power transmission control function to control power to be transmitted to the power receiver,

wherein the transmission/reception circuit portion for the power feeding device comprises an antenna circuit, a rectifier circuit, a mixer, a demodulation circuit, a first oscillator circuit, a first power supply circuit, a second oscillator circuit, and a second power supply circuit,

wherein the power receiving device portion comprises;

a transmission/reception circuit portion for the power receiving device portion, configured to transmit and receive an electromagnetic wave;

a signal processing circuit portion for the power receiving device portion, configured to process an electrical signal of the electromagnetic wave to be transmitted and received by the transmission/reception circuit portion for the power receiving device portion;

a power storage portion including a secondary battery, configured to store power transmitted from the power feeding device and supply power to be consumed by a power load portion; and

a detection portion configured to detect a voltage, a current, or a voltage and a current output from the secondary battery,

wherein the signal processing circuit portion for the power receiving device portion has a power reception control function to control power to be received from the power feeding device, and

wherein the mixer mixes a first signal generated by the first power supply circuit and the first oscillator circuit with a second signal generated by the second power supply circuit and the second oscillator circuit.

8. The wireless power feeding system according to claim 7, wherein the transmission/reception circuit portion for the power receiving device portion comprises an antenna circuit, a rectifier circuit, a modulation circuit, a demodulation circuit, an oscillator circuit, and a power supply circuit.

9. The wireless power feeding system according to claim 7,

wherein the power receiver comprises a memory portion configured to store identification information to be read by the signal processing circuit portion for the power receiving device portion, and

wherein the signal processing circuit portion for the power feeding device has an identification function to identify the identification information.

10. A wireless power feeding method comprising:

a first step of receiving a first electromagnetic wave transmitted from a power receiver by a power feeding device and detecting a position and a resonant frequency of the power receiver from a signal transmitted via the first electromagnetic wave with the power feeding device;

a second step of mixing a first signal with a second signal on a basis of the position and the resonant frequency of the power receiver and transmitting power from the power feeding device to the power receiver via a second electromagnetic wave; and

a third step of storing the power transmitted from the power feeding device in a secondary battery of the power receiver.

wherein the second electromagnetic wave includes two signals having different frequencies.

11. The wireless power feeding method according to claim 10, wherein a plurality of signals having different frequencies is transmitted via the first electromagnetic wave from the power receiver to the power feeding device.

12. The wireless power feeding method according to claim 10, wherein two different frequencies are detected as the resonant frequency.

13. The wireless power feeding method according to claim 10, wherein the first signal is a base carrier for the power feeding device.

14. The wireless power feeding method according to claim 10, wherein the power receiver detects a voltage, a current, or a voltage and a current output from the secondary battery and transmits a power feeding request signal or a power reception end signal to the power feeding device on a basis of a detection information.

15. The wireless power feeding method according to claim 10, further comprising a step of recognizing identification information of the power receiver with the power feeding device, before the first step.