摘要 |
An infrared intrusion detector wherein a plurality of separate radiation receiving regions or fields of view are focused by a single focusing optic, for instance a reflector or a Fresnel lens upon a single sensor element through an elongate or lengthwise extending radiation collecting element. The radiation collecting element can be constituted by an internally metal coated tube or a transparent body having a reflecting surface layer or coating, wherein the reflection coating is interrupted by radiation inlet openings. The infrared radiation which is focused by the focusing optic enters through such openings into the interior of the radiation collecting element and arrives, after having been reflected a number of times, at the sensor element which is mounted at an end side thereof. |