Patent ID: 9229069
Filing Date: 2016-01-05
CPC Classification: G01R,G01V,H02J

Claim Text:
1. A method for detecting whether or not a metal foreign object is present on a contactless power supply device that supplies power to a power reception device included in an electrical appliance using an electromagnetic induction phenomenon, the method comprising: transmitting an oscillation signal from the contactless power supply device to the power reception device; detecting, from the oscillation signal received by the power reception device, a modulating wave based on a change in magnetic flux caused by the presence of a metal foreign object; generating a modulated wave signal by modulating a carrier signal in accordance with the modulating wave to transmit the modulating wave to the contactless power supply device, and transmitting the modulated wave signal from the power reception device to the contactless power supply device; and receiving the modulated wave signal transmitted from the power reception device with the contactless power supply device, and determining whether or not a metal foreign object is present based on comparison between a reference cycle and the cycle of a demodulated signal demodulated from the modulated wave signal, the cycle of the demodulated signal corresponding to the cycle of the modulating wave.