NON-CONTACT CHARGING METHOD
First Claim
1. A non-contact charging method including setting down a battery-powered device (50) on a charging platform (10), electromagnetically coupling a power receiving coil (51) in the battery-powered device (50) to a power transmission coil (11) in the charging platform (10), transmitting power from the power transmission coil (11) to the power receiving coil (51) by electromagnetic induction, and charging a battery (52) in the battery-powered device (50) using power induced in the power receiving coil (51),the non-contact charging method characterized by detecting the charging current of the battery (52) on the battery-powered device (50) side, detecting the transmission efficiency from the charging current, comparing the detected transmission efficiency to an efficiency threshold value, determining that a foreign object has been set down on the charging platform (10) when the detected charging efficiency is less than the efficiency threshold value and determining that a foreign object has not been set down on the charging platform (10) when the detected charging efficiency is greater than the efficiency threshold value, and suspending foreign object detection during a time period including a fluctuation in the charging current.
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Accused Products
Abstract
A non-contact charging method, in which a battery-powered device is set down on a charging platform, a power receiving coil in the battery-powered device is electromagnetically coupled to a power transmission coil in the charging platform, power is transmitted from the power transmission coil to the power receiving coil by electromagnetic induction, and a battery (52) in the battery-powered device is charged. The charging current of the battery is detected on the battery-powered device side, the transmission efficiency is detected from the detected charging current, the detected transmission efficiency is compared to an efficiency threshold value, it is determined that a foreign object is on the charging platform when the detected charging efficiency is less than the efficiency threshold value and it is determined that a foreign object is not on the charging platform when the detected charging efficiency is greater than the efficiency threshold value.
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Citations
8 Claims
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1. A non-contact charging method including setting down a battery-powered device (50) on a charging platform (10), electromagnetically coupling a power receiving coil (51) in the battery-powered device (50) to a power transmission coil (11) in the charging platform (10), transmitting power from the power transmission coil (11) to the power receiving coil (51) by electromagnetic induction, and charging a battery (52) in the battery-powered device (50) using power induced in the power receiving coil (51),
the non-contact charging method characterized by detecting the charging current of the battery (52) on the battery-powered device (50) side, detecting the transmission efficiency from the charging current, comparing the detected transmission efficiency to an efficiency threshold value, determining that a foreign object has been set down on the charging platform (10) when the detected charging efficiency is less than the efficiency threshold value and determining that a foreign object has not been set down on the charging platform (10) when the detected charging efficiency is greater than the efficiency threshold value, and suspending foreign object detection during a time period including a fluctuation in the charging current.
Specification