LIFT DOOR SAFETY EDGE
May 1st 2005

A lift-door safety edge from TL Jones combines two and threedimensional detection.

In addition to the 212 infrared beams making up the 2D light curtain between lift doors, the D300SL has four clusters of strategically placed 3D transmitter diodes that monitor the landing area in front of the lift entrance.

These diode clusters are positioned at three separate angles of 30, 45 and 60°; several are angled downwards to detect any flat surfaces, such as the tops of trolleys. The active area of 3D detection covers between 250 and 1200mm when the doors are opening or closing.

The software discounts stationary objects left in front of the lift and parallel traffic passing through the landing area: 15sec of continuous 3D detection or six 3D detections, without a corresponding 2D reading, disables the 3D detection function that can only be re-enabled via an obstruction of a 2D beam.