TARGET OBJECT DETECTION DEVICE

摘要

A target object detection device comprises: a pyroelectric element for outputting a current signal in response to infrared volume change; a current-voltage converter circuit including an operational amplifier, a feedback capacitor element, and a discharge circuit and converting the current signal into a voltage signal; an AD converter circuit for converting the voltage signal into a first digital signal; a digital filter for performing arithmetic processing on the first digital signal to extract, from the waveform represented by the first digital signal, a detection component having a frequency included in the frequency band corresponding to a target object and for generating a second digital signal representing the waveform of the detection component; a determination circuit for detecting the target object on the basis of the second digital signal; and a control unit for controlling the discharge circuit on the basis the cycle corresponding to a predetermined frequency less than or equal to the lower limit of the frequency band and discharging charge stored in the capacitor element.