| 摘要 |
<p>The sensor (12) has a focusing astigmatic mirror (2) for electromagnetic radiation (8) and a passive infrared detector for detecting the electromagnetic radiation, where the mirror has a concavely curved reflecting surface. Shape of the reflecting surface is defined in sectional planes by a parabola, where the sectional planes are perpendicular to each other. The mirror is provided with a third sectional plane, where a profile of the reflecting surface is defined as expression of polar coordinates in the third plane. The mirror and the detector are secured at a support. The detector is designed as a movement alarm unit, passive infrared detector and a thermopile (3). An independent claim is also included for a method for detecting people, animals or objects.</p> |
