REFLECTION MIRROR FOR INTRUSION DETECTOR

摘要

PURPOSE:To enable detection of the monitor zone over a wide range with high sensitivity by disposing plural concave mirrors in such a way that these concave mirrors focus at the same point and providing a light projecting part and photodetecting part disposed with a light emitting element or photodetector at said focus. CONSTITUTION:A holder 2 for a mirror body is disposed with concave mirrors 1-a-1-f into a petal shape and a light emitting element or photodetector 3 is disposed in front of the central part of said mirrors so as to be positioned approximately at the focus of the mirrors 1-a-1-f. The projecting angles of the mirrors 1-a-1-f are preliminarily so set that the visual field pattern of the luminous flux projected from the part 6 is irradiated at a prescribed interval on a projecting surface 5. The reflection mirror of such intrusion detector is set at an optical light projecting and photodetecting field pattern and since the light projecting and photodetecting part of the same construction is used, the monitor zone over a wide range is detected with high accuracy.