Patent ID: 7388479

Claim:
A human sensing back-up alarm device comprising: a PCB control part for controlling an alarm sound; a human sensing part for electrically sensing an optical signal; and a speaker part for converting an electric signal into a mechanical signal, wherein the PCB control part includes a clock generator for generating the alarm sound, a clock divider for dividing clocks generated from the clock generator, a terminal unit, a loudness control unit for adjusting a loudness of the alarm sound, a non-continuous sound control unit for generating a non-continuous sound, a speaker drive unit for driving the speaker part and a power source for stabilizing power applied to a vehicle; wherein the human sensing part includes an IR sensor for converting an IR signal into the electric signal, a primary amplifying unit for amplifying micro signals generated form the IR sensor and having basic filter characteristics, a secondary amplifying unit for secondarily amplifying the primarily amplified signal and having a band pass filter function for shielding noise components, and a signal detector for detecting effective signals.