Detection apparatus, power receiving apparatus, non-contact power transmission system and detection method

• US 10,036,767 B2
• Filed: 09/21/2016
• Issued: 07/31/2018
• Est. Priority Date: 12/21/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Komiyama, Shinji
• Primary Examiner(s): PATEL, DHARTI HARIDAS
• Application Number:
  US15/271,852
• Publication Number:
  US 20170010307A1
• Time in Patent Office: 678 Days
• Field of Search: 307104
• CPC Class Codes: G01R 15/18 using inductive devices, e.g. transformers
• CPC Class Codes: G01R 21/006 Measuring power factor
• CPC Class Codes: G01V 3/10 using induction coils
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices

Abstract

Disclosed herein is a detection apparatus including: a resonant circuit provided with a Q-factor measurement coil and one or more capacitors to serve as a circuit for receiving pulses; a response-waveform detecting section configured to detect the waveform of a response output by the resonant circuit in response to the pulses; and a Q-factor measuring section configured to measure a Q factor of the resonant circuit from the response waveform detected by the response-waveform detecting section. It is possible to increase the precision of detection of a metallic foreign substance existing between a power transmitting side and a power receiving side.

Claims

1. A detection apparatus comprising:

a signal source configured to input a signal to a resonant circuit, the resonant circuit including a coil and one or more capacitors;

a response-waveform detecting section to detect a response waveform that is output by the resonant circuit in response to the signal;

a Q-factor measuring section configured to measure a Q factor of the resonant circuit from the response waveform detected by the response-waveform detecting section; and

a determination section configured to determine whether or not a foreign object exists in close vicinity of the coil by comparing the Q factor measured by the Q-factor measuring section with a predetermined reference value.

2. The detection apparatus of claim 1, wherein the signal source comprises:

a pulse generator with circuitry to generate signal pulses; and

a resistor to generate the signal based on the signal pulses.

3. The detection apparatus of claim 1, further comprising a control section operative to stop transmission of electric power by a power transmitter to a power receiver in response to detection of a foreign object in the close vicinity of the coil.

4. A power transmitting apparatus comprising:

a signal source configured to input a signal to a resonant circuit, the resonant circuit including a coil and one or more capacitors;

a response-waveform detecting section to detect a response waveform that is output by the resonant circuit in response to the signal;

a Q-factor measuring section configured to measure a Q factor of the resonant circuit from the response waveform detected by the response-waveform detecting section;

a determination section configured to determine whether or not a foreign object exists in close vicinity of the coil by comparing the Q factor measured by the Q-factor measuring section with a predetermined reference value; and

a power transmitting section configured to transmit electric power wirelessly to a power receiving apparatus.

5. The power transmitting apparatus of claim 4, wherein the signal source comprises:

a pulse generator with circuitry to generate signal pulses; and

a resistor to generate the signal based on the signal pulses.

6. The power transmitting apparatus of claim 4, further comprising a control section operative to stop transmission of electric power by the power transmitting section to a power receiver in response to detection of a foreign object in the close vicinity of the coil.

7. A method comprising:

receiving a signal in a resonant circuit, the resonant circuit including a coil and one or more capacitors;

detecting a response-waveform output by the resonant circuit in response to the signal;

measuring a Q-factor of the resonant circuit from the response-waveform; and

determining whether or not a foreign object exists in close vicinity of the coil by comparing the measured Q factor with a predetermined reference value.

8. A method comprising:

receiving the signal in a resonant circuit, the resonant circuit including a coil and one or more capacitors;

detecting a response-waveform output by the resonant circuit in response to the signal;

measuring a Q-factor of the resonant circuit from the response-waveform;

determining whether or not a foreign object exists in close vicinity of the by comparing the measured Q factor with a predetermined reference value, transmit electric power wirelessly to a power receiving apparatus; and

wirelessly transmitting electric power.