ELECTRIC POWER TRANSMITTING AND RECEIVING DEVICE, ELECTRIC POWER TRANSMITTING DEVICE AND ELECTRIC POWER RECEIVING DEVICE

• US 20100148939A1
• Filed: 11/16/2009
• Published: 06/17/2010
• Est. Priority Date: 12/16/2008
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Niwa, Yuhei, YAMADA, Masaaki, Takaki, Taku
• Granted Patent: US 8,405,486 B2
• Time in Patent Office: Days
• US Class Current: 340/10.340
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• 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 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

In wireless electric power transmission and reception, the efficiency of transmission and reception is improved and a device to which electric power can be supplied is specified to improve security.

Two antennas with different resonance frequencies are provided, and the resonance frequencies of a reception loop and a reception coil of a receiver are corrected in accordance with a reception status of a carrier transmitted from a transmitter to improve the efficiency of transmission and reception. Further, data transmitted from the transmitter are demodulated on the basis of the reception levels of two antennas with different resonance frequencies, and the data are transmitted to the transmitter using a reflective wave to perform data transmission and reception. By using this, device authentication is performed, and security is improved.

Claims

1. An electric power transmitting and receiving device for transmitting electric power from a transmitting device to a receiving device using magnetic resonance at a predetermined resonance frequency, wherein the transmitting device includes:

a transmission unit which includes a transmission loop and a transmission coil and transmits the electric power;

a supplying unit which supplies the electric power to the transmission unit;

a detection unit which detects a frequency transmitted from the transmission unit; and

a transmitter which includes a first correction unit for correcting the frequency transmitted from the transmission unit, and

the receiving device includes;

a reception unit which includes a reception loop and a reception coil for receiving the electric power transmitted from the transmission unit;

a first antenna having a resonance frequency higher than that of the reception unit;

a second antenna having a resonance frequency lower than that of the reception unit;

a comparing unit which compares reception levels between the first antenna and the second antenna; and

a receiver which includes a second correction unit for correcting the resonance frequency of the reception unit on the basis of the comparison result of the comparing unit.

2. The electric power transmitting and receiving device according to claim 1, wherein

the transmitter further includes a frequency modulation unit which changes a frequency in accordance with digital data transmitted to the receiver, and the receiver further includes a processing unit which demodulates digital data on the basis of the reception levels of the first antenna and the second antenna.

3. The electric power transmitting and receiving device according to claim 2, wherein

transmission and reception of the digital data are performed during a period which is different from a period during which electric power is transmitted and received.

4. An electric power transmitting device for transmitting electric power using magnetic resonance at a predetermined resonance frequency, the device comprising:

a transmission unit which includes a transmission loop and a transmission coil and transmits the electric power;

a supplying unit which supplies the electric power to the transmission unit;

a detection unit which detects a frequency transmitted from the transmission unit; and

a transmitter which includes a first correction unit for correcting the frequency transmitted from the transmission unit.

5. An electric power receiving device for receiving electric power using magnetic resonance at a predetermined resonance frequency, the device comprising:

a reception unit which includes a reception loop and a reception coil for receiving the electric power;

a first antenna having a resonance frequency higher than that of the reception unit;

a second antenna having a resonance frequency lower than that of the reception unit;

a comparing unit which compares reception levels between the first antenna and the second antenna; and

a receiver which includes a second correction unit for correcting the resonance frequency of the reception unit on the basis of the comparison result of the comparing unit.

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

the reception loop, the reception coil, the first antenna, and the second antenna are arranged on the same plane.

7. The electric power receiving device according to claim 5, wherein

each electric power received by the reception loop, the reception coil, the first antenna, and the second antenna is added.

8. The electric power receiving device according to claim 5, wherein

the first antenna and the second antenna are antennas used in a GPS, television broadcasting, and noncontact communications using an IC card.