| 摘要 |
PURPOSE:To improve the monitoring function with a remarkable expansion of the detection range in a reflection type infrared ray invasion detector by arranging the detector employing a plurality of reflection bodies and one or several photo detectors. CONSTITUTION:Infrared rays emitted from a projector 1 adapted to emit infrared rays conically hit reflection bodies 5a and 5b on an opposed surface 6 plotting a projection beam distribution pattern 3 and reflected infrared rays enter a photo detector 2 according to a received light beam distribution pattern 4. This forms two light projection/reception routes at respective outer rims of a projected light beam and a received light beam thereby enabling a remarkable expansion of the detection range. |
