US 2003/0189487 A1 · Perimeter monitoring system

Abstract

A perimeter monitoring system is arranged to detect passage across a perimeter of an area. The system primarily includes an emitter, a retroreflector, a detector and an alarm. The emitter provides a modulated visible laser beam. The retroreflector is arranged to direct the beam along a segment of the perimeter and return the beam along the segment. The detector includes a device that blocks reception of light outside an angle of less than 5 degrees. One or more local or remote alarms are activated in response to the signal. For example, a remote alarm is located on the inside of a residence window where it is activated by another visible laser beam. Alignment of the peripheral monitoring system is less costly and false alarms are less likely than with known systems.

Claims20

Dependent claims

A perimeter monitoring system comprising:

a. a first and a second mounting apparatus each comprising a tube comprising an axial interior slot and a pivot;
b. a reflector assembly positioned to receive a beam of light along a segment of a perimeter of an area to be monitored and to provide a returned beam, the reflector assembly comprising a reflector secured to the pivot of the first mounting apparatus;
and
c. a monitor comprising:
(1) an enclosure;
and
(2) a circuit board comprising an emitter that provides the beam of light and a detector that provides a signal when an interruption of the returned beam is detected, wherein:
(a) the circuit board is mounted in the slot of the second mounting apparatus;
and
(b) the pivot of the second mounting apparatus is secured to the enclosure;
and
(3) an alarm controller that activates an alarm in response to the signal.

9 more elements

Dependencies are inferred from the claim text.

Perimeter monitoring system

Life of this patent

Perimeter monitoring system

Life of this patent

Abstract

Claims20