DETECTING APPARATUS FOR WAKE-UP SIGNAL

摘要

PURPOSE: A detecting apparatus for a wake-up signal is provided to extract a weak wake-up signal without loss even when using one infrared ray detector. CONSTITUTION: A reference signal generating unit(25) generates a square wave of a certain duty cycle corresponding to a normal wake-up signal. A first comparison circuit unit(30) compares the output of a dividing circuit unit(20) with the output with the reference signal generating unit. The first comparison circuit unit judges whether or not the difference between two output signals occurs. If the output of the first comparison circuit unit is over a certain value, the second comparison circuit unit(35) judges the output as the normal wake-up signal and outputs the wake-up signal.