METAL FOREIGN MATTER DETECTOR, WIRELESS POWER FEEDING DEVICE, WIRELESS POWER RECEIVING DEVICE, AND WIRELESS POWER TRANSMISSION SYSTEM

PROBLEM TO BE SOLVED: To heighten the accuracy of detecting metal foreign matter.SOLUTION: A metal foreign matter detector 14A comprises: a sensor unit S having at least one antenna coil L3 that generates a vibration signal Vb upon receiving a magnetic field or an electric current; an integration circuit 144 capable of obtaining an integrated value IV of the waveform of a signal Vd that corresponds to the vibration signal Vb; and a determination circuit 145 for determining whether there is metal foreign matter approaching the antenna coil L3 on the basis of the integrated value IV and a reference integrated value CIV that is an integrated value IV when there is no approaching metal foreign matter. The integrated value IV and the reference integrated value CIV are assumed to be obtained by integrating a waveform for the same number of waves.SELECTED DRAWING: Figure 3 【課題】金属異物の検出精度を高める。【解決手段】金属異物検出装置１４Ａは、磁界または電流を受けて振動信号Ｖｂを発生する少なくとも１つのアンテナコイルＬ３を有するセンサ部Ｓと、振動信号Ｖｂに対応する信号Ｖｄの波形の積分値ＩＶを得る積分回路１４４と、この積分値ＩＶと、接近する金属異物が無いときの積分値ＩＶである基準積分値ＣＩＶとに基づいて、アンテナコイルＬ３に接近する金属異物の有無を判定する判定回路１４５とを備える。積分値ＩＶと基準積分値ＣＩＶとは、同一波数分の波形を積分して得られるものとする。【選択図】図３