Sensor for automatic doors

A sensor for an automatic door, comprising:

• image pickup means for taking an image of a predetermined area which covers a track of a door;
• distance measurement means for, upon receiving an output from said image pickup means, measuring a distance between said image pickup means and each object which is in the predetermined area and observed in the image taken of the predetermined area;
• floor detection means for, upon receiving an output from said distance measurement means, detecting a floor and a height and position of the floor such that the floor is distinguished from objects for which the distance between these objects and said image pickup means has been measured;
• object height/position detection means for, upon receiving outputs from said distance measurement means and said floor detection means, detecting a height and position of an object, other than the floor, which is in the predetermined area and observed in the image taken of the predetermined area, and is located at a different height and position relative to the height and position of the floor;
• door position detection means for detecting whether the door is in an open position or a closed position along the track;
• door position identification means for, upon receiving an output from said door position detection means, identifying a position of the door in the image taken of the predetermined area, based upon whether the door is in an open position or a closed position as detected by said door position detection means;
• judgement means for, upon receiving outputs from said object/height position detection means and said door position identification means, judging whether the object, which is other than the floor, is the door or an object other than the door;
• and
• output means for, upon receiving an output from said judgement means, outputting an object detection signal for an object that is observed in the image taken of the predetermined area and is neither the floor nor the door.