METHOD AND APPARATUS FOR DETECTING THE PRESENCE AND LOCATION OF OBJECTS IN A FIELD VIA SCANNED OPTICAL BEAMS

An optical system and method for detecting the presence and location of multiple objects in a field. The optical system has at least one light source to generate a beam, which beam is scanned by at least one first reflecting surface to generate at least three sets of beams. A first and second set of beams are overlapped across the field by at least one second reflecting surface and a third set overlaps the field without the second reflecting surface. The beam intensity is measured by at least one detection means.