METHOD FOR DETECTING FOREIGN MATERIAL, AND APPARATUS AND SYSTEM THEREFOR
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Abstract
The present invention relates to a method for detecting foreign material, and an apparatus and a system therefor, and a method for detecting foreign material in a wireless power transmitter, according to one embodiment of the present invention, comprises the steps of: measuring a quality factor value, which corresponds to a reference operation frequency, when an object is sensed; searching for a current peak frequency having a maximum quality factor value within an operation frequency band; receiving, form a wireless power receiver, a foreign material detection state packet including information on a reference peak frequency; correcting the measured quality factor value by using a difference value between the current peak frequency and the reference peak frequency; and determining whether the foreign material exists by comparing the corrected quality factor value with a predetermined quality factor threshold value. Therefore, the present invention has an advantage of enabling foreign material to be more effectively and accurately detected.
24 Citations
31 Claims
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1-12. -12. (canceled)
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13. A method of detecting a foreign object in a wireless power transmitter, the method comprising:
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measuring a quality factor value corresponding to a reference operating frequency when an object is detected; searching for a current peak frequency having a maximum quality factor value within an operating frequency band; receiving a foreign object detection status packet including information on a reference peak frequency from a wireless power receiver; calibrating the measured quality factor value using a difference between the current peak frequency and the reference peak frequency; and comparing the calibrated quality factor value with a predetermined quality factor threshold value to determine whether the foreign object is present. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. A wireless power transmitter, comprising:
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a quality factor measurement unit configured to measure a quality factor value corresponding to a reference operating frequency when an object is detected; a peak frequency search unit configured to search for a current peak frequency having a maximum quality factor value within an operating frequency band; a communication unit configured to receive a foreign object detection status packet including information on a reference peak frequency from a wireless power receiver; a calibration unit configured to calibrate the measured quality factor value using a difference between the current peak frequency and the reference peak frequency; and a detection unit configured to compare the calibrated quality factor value with a predetermined quality factor threshold value to determine whether the foreign object is present. - View Dependent Claims (21, 22, 23, 24, 25, 26)
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27. A wireless power receiver, comprising:
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a communication unit configured to transmit a foreign object status packet to a wireless power transmitter, and to receive a response signal corresponding to the foreign object status packet from the wireless power transmitter; and a controller configured to generate the foreign object status packet including a mode information, wherein the controller identifies whether an information on a reference peak frequency is included in the foreign object status packet based on the mode information, and wherein the reference peak frequency is a resonant frequency at which a maximum quality factor value is measured corresponding to a coil included in the wireless power transmitter in a state that the power of the wireless power receiver is turned off and there is no foreign object. - View Dependent Claims (28, 29, 30, 31)
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Specification