POWER TRANSMISSION APPARATUS WIRELESSLY TRANSMITTING POWER TO POWER RECEIVING APPARATUS

• US 20170155280A1
• Filed: 11/16/2016
• Published: 06/01/2017
• Est. Priority Date: 11/27/2015
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Okamoto, Yoshihiko
• Granted Patent: US 10,511,190 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

A power transmission apparatus includes a power transmission unit that wirelessly transmits power to an electronic device, a foreign substance detection unit that detects a foreign substance affecting power transmission performed by the power transmission unit, a loop shaped power transmission antenna serving as an antenna for the power transmission unit transmitting power to the electronic device, and a foreign substance detection antenna for the foreign substance detection unit detecting the foreign substance, wherein the foreign substance detection antenna is arranged at a predetermined distance or more from the power transmission antenna in a vertical direction to a loop direction of the power transmission antenna.

Claims

1. A power transmission apparatus comprising:

a power transmission unit configured to wirelessly transmit power to an electronic device;

a foreign substance detection unit configured to detect a foreign substance affecting power transmission performed by the power transmission unit;

a loop shaped power transmission antenna serving as an antenna for the power transmission unit transmitting power to the electronic device; and

a foreign substance detection antenna for the foreign substance detection unit detecting the foreign substance,

wherein the foreign substance detection antenna is arranged at a predetermined distance or more from the power transmission antenna in a vertical direction to a loop direction of the power transmission antenna.

2. The power transmission apparatus according to claim 1, wherein the foreign substance detection antenna is formed so as to surround the power transmission antenna when viewed in the vertical direction of the loop direction.

3. The power transmission apparatus according to claim 2, wherein a loop of the foreign substance detection antenna is formed on an outer side of a range in which the power transmission antenna is arranged.

4. The power transmission apparatus according to claim 2, wherein the number of winds of the foreign substance detection antenna is 1.

5. The power transmission apparatus according to claim 1, wherein external form sizes of the foreign substance detection antenna and the power transmission antenna are the same.

6. The power transmission apparatus according to claim 1, wherein the foreign substance detection antenna is arranged on an opposite side to the electronic device across the power transmission antenna.

7. The power transmission apparatus according to claim 1, wherein the predetermined distance is a distance at which a magnetic field intensity in a range in which the power transmission antenna is arranged falls within 15% from an average magnetic field intensity of the range.

8. The power transmission apparatus according to claim 1, wherein the power transmission antenna and the foreign substance detection antenna are arranged so that central axes match each other.

9. The power transmission apparatus according to claim 1, wherein the foreign substance detection antenna further serves as an antenna for performing communication with the electronic device.

10. The power transmission apparatus according to claim 1, wherein magnetic sheets are attached to the power transmission antenna and the foreign substance detection antenna.

11. The power transmission apparatus according to claim 1, wherein the foreign substance is any of a metal object, an IC card, or an electronic device equipped with an IC tag.

12. A method for controlling a power transmission apparatus that provides power to an electronic device, the method comprising:

setting an impedance matching state of the power transmission apparatus and the electronic device;

supplying power to a foreign substance detection antenna of the power transmission apparatus;

obtaining a voltage standing wave ratio;

comparing the obtained voltage standing wave ratio against a predetermined range; and

determining, based on a result of comparing the obtained standing wave ratio against the predetermined range whether a foreign substance other than the electronic device exists in the vicinity of the power transmission apparatus.

13. A method for controlling a power transmission apparatus that provides power to an electronic device, the method comprising:

supplying power to the electronic device;

setting an impedance matching state of the power transmission apparatus and the electronic device;

obtaining a voltage standing wave ratio; and

determining, based on a result of comparing the obtained standing wave ratio against the predetermined range whether a foreign substance other than the electronic device exists in the vicinity of the power transmission apparatus,

wherein, if it is determined that a foreign substance other than the electronic device exists, supplying power to the electronic device is terminated.