METALLIC FOREIGN OBJECT DETECTOR, WIRELESS POWER TRANSMITTING DEVICE, WIRELESS POWER RECEIVING DEVICE, AND WIRELESS POWER TRANSMISSION SYSTEM

An object of the present invention is to improve the accuracy of detection of the metallic foreign object. A metallic foreign object detector includes a sensor part having at least one antenna coil that receives a magnetic field or current to generate a vibration signal, an integration circuit that acquires the integral value of a waveform of a signal corresponding to the vibration signal, and a determination circuit that determines the presence/absence of a metallic foreign object approaching the antenna coil based on the integral value and a criterion integral value which is the integral value obtained in the absence of the approaching metallic foreign object. The integral value and the criterion integral value are obtained by integrating the waveform having the same wavenumber.