METHOD FOR DETECTING FOREIGN MATERIAL, AND DEVICE AND SYSTEM THEREFOR
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Abstract
The present invention relates to a method for detecting a foreign material, and a device and system therefor. The method for detecting a foreign material in a wireless power transmitter provided with a resonance circuit for wirelessly transmitting power according to an embodiment of the present invention comprises: a step of detecting an object disposed in a charging area; a step of measuring a quality factor value of a resonance circuit, following the detection of the object; a step of identifying a wireless power receiver by sending out a detection signal; a step of determining a critical value for detecting a foreign material, on the basis of a reference quality factor value received from the identified wireless power receiver; and a step of judging whether or not the foreign material exists, by comparing the measured quality factor value and the determined critical value, wherein the critical value may be determined by applying a weight which increases in accordance with the reference quality factor value. Accordingly, the present invention has the advantage of detecting a foreign material more effectively and accurately.
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Citations
31 Claims
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1-11. -11. (canceled)
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12. A method of detecting a foreign object in a wireless power transmitter, the method comprising:
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measuring a first quality factor value at a first frequency; measuring a second quality factor value at a second frequency; and determining whether the foreign object is present based on the first quality factor value and the second quality factor value, wherein the second frequency is greater than the first frequency. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A method of detecting a foreign object in a wireless power transmitter, the method comprising:
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calculating a first quality factor average value based on quality factor values measured at a plurality of frequencies in an upper-limit frequency band of an operating frequency band; calculating a second quality factor average value based on quality factor values measured at a plurality of frequencies in a lower-limit frequency band of the operating frequency band; and determining whether the foreign object is present in a charging area based on the first quality factor average value and the second quality factor average value. - View Dependent Claims (19, 20, 21)
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22. A wireless power transmitter comprising:
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a quality factor measurement unit configured to measure a first quality factor value at a first frequency and a second quality factor value at a second frequency; and a detector configured to determine whether a foreign object is present in a charging area based on the first quality factor value and the second quality factor value, wherein the second frequency is greater than the first frequency. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification