An intruder detection device provides first and second detection areas which
are
covered by first and second PIR sensors. When intrusion of an object is detected
in these areas, the detection signals are amplified by amplifiers, and then processed
in a control unit such that orders for generating alarms are output from alarm
output units to a monitoring station. While these processed detection signals are
output to the alarm output units, the control unit sends other processed signals
to LED display units, so that the LED display units turn on alarm lights. The intruder
detection device also has a device for separating the object detection areas of
the first and second PIR sensors such that their detection areas do not overlap.
