Electronic device having substrate mounting sonic wave output element that outputs and receives sonic wave, pedestal to which the substrate is attached made of a nonconductive material, frame to which the pedestal is attached made of a conductive material, and conductive tape or conductive leaf spring which contacts substrate and frame

摘要

A human presence sensor unit in which an ultrasonic wave sensor is mounted is fixed to a frame sheet metal of an image forming apparatus with a pedestal interposed therebetween. The pedestal is made of a synthetic resin material, and the frame sheet metal is made of a metal material. As the pedestal and the frame sheet metal are made of different materials, a difference in the acoustic impedance is produced between the pedestal and the frame sheet metal.