Patent ID: 8368535

Claim:
An intrusion detector, comprising: a passive sensor configured to detect electromagnet radiation associated with an object entering an area to be monitored; optical means configured to direct the electromagnetic radiation associated with the object to the passive sensor, wherein the optical means are provided with a mirror curved in two directions on a vertical axis for forming at least one protective curtain extending in a vertical plane in the area to be monitored, wherein the mirror comprises at least two groups of mirror segments, and wherein a first mirror segment of one group has a first mirror segment inclination/declination angle equal to α and a first mirror segment azimuth angle equal to β, and a second mirror segment of a second group has a second mirror segment inclination/declination angle equal to α and a second mirror segment azimuth angle equal to −β; and an alarm unit connected to the passive sensor, the alarm unit configured to generate an alarm in the event that a value corresponding to the electromagnetic radiation associated with the object being detected by the passive sensor is greater than a maximum value or less than a minimum value, wherein the passive sensor is disposed on an optical axis at a focal distance of the first mirror segment and the second mirror segment.