| 摘要 |
In a lift installation in which a multi-beam curtain (primary beam) extends across a lift car door opening, auxiliary transmitters direct secondary beams towards a detection zone in front of landing doors. The multi-beam curtain is intercepted by a passenger entering the lift to prevent premature door closure. However, premature closure is also prevented when a passenger stands in front of the landing doors, thereby causing some of the secondary beam to be reflected onto auxiliary receivers. This provides a low cost solution to the problem of non-detection of an obstruction in the closing path of the landing doors, but not intercepting the primary beam system and also provides an increase in the passenger convenience of the lift, as the doors are held open for a passenger approaching the lift, but not yet interrupting the primary beams. |
