Metal foreign object detection device

Abstract

This invention provides a metal foreign object detection device with an easily miniaturized structure. To achieve this objective, one example of the metal foreign object detection device 1 disclosed herein includes: a cavity resonator 10 having a through-hole 11 for the object to be detected and a high-frequency aperture 12; a high-frequency transmitting circuit 20; a high-frequency receiving circuit 30; a first spacer 51; a second spacer 52; and a mechanism 60 electrically connecting the high-frequency transmitting circuit 20 and the high-frequency receiving circuit 30. The aperture of the through-hole 11 is constant to generate a standing wave of a high-frequency signal. An inlet 41, a first spacer 51, and the high-frequency transmitting circuit 20 are sequentially arranged at one opening of the high-frequency aperture 12 of the cavity resonator 10, and an outlet 42, a second spacer 52, and the high-frequency receiving circuit 30 are sequentially arranged at the other opening 12B. When the object to be detected contains metal passing through the cavity resonator 10, the high-frequency receiving circuit 30 detects the changes in the frequency and amplitude of the received high-frequency signal compared to when no metal is present, and obtains metal detection information based on these changes.

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