PHOTOELECTRIC OBSTRUCTION DETECTOR FOR ELEVATOR DOORWAYS

摘要

In the entranceway between an elevator car and a floor are two oppositely sliding doors (10, 20). The approach of these doors is controlled by a detection system that senses the presence of objects between the doors. This system includes, on each door, a plurality of emitters (12, 22) which are vertically spaced apart the door edge (11, 21), for radiating non-collimated light towards the edge of the other door. At the top and bottom portions of each door edge there is a sensor (13, 23), which can receive the radiation for the emitters on the other door edge. The emitters on each door edge are sequentially turned on and the sensors on the opposite door edge provide a corresponding signal as they are turned on, unless an obstruction is in the way, causing the detection system to generate a signal that thus indicates that an objet is between the doors.