OBJECT SENSING SYSTEM FOR USE WITH AUTOMATIC SWING DOOR

摘要

An object sensor for use with an automatic swing door includes a light emitter, which is mounted on a door surface of the automatic swing door. The light emitter emits a light beam toward a floor. A distance detector is mounted on the door surface. The distance detector receives the light beam reflected from an object and develops an output signal having a value representing the distance of the object from the distance detector. A contro l unit makes a judgment based on the value of the output signal of the distanc e detector as to whether the object is approaching the door surface. The control unit stores the value of the distance detector output signal representing the distance between the distance detector and the floor, as a reference value. A dead zone is defined for the reference value to extend from the floor to a predetermined distance above the floor. When the value of the distance detector output signal is outside the dead zone, the control units judges the object to be approaching the door surface.