Patent ID: 8510990
Filing Date: 2013-08-20
Classification: E05F,E05Y,G01S

Abstract:
1. A presence detector for a door assembly including a door which closes a door entrance and which is characterized by a position relatively to the door entrance, the detector comprising: a transducer assembly mounted to the door assembly i) that emits a plurality of ultrasound detecting beams adjacent the door entrance yielding a detecting zone adjacent the door entrance, ii) that modifies the detecting zone in accordance with the position of the door and, iii) that triggers a detecting signal indicative of a body located said adjacent the door entrance when the body intersects at least one of the plurality of ultrasound detecting beams; wherein each of the plurality of ultrasound detecting beams being characterized by a length, wherein the transducer assembly further modifies the detecting zone according to environmental changes adjacent the door entrance so that the length of each of the plurality of ultrasound detecting beams is invariant with the environmental changes.