Composite sensor for door and automatic door system

Abstract

A first area ( 16 ) for detecting an object is formed by a radio wave or an ultrasonic wave, and a second area ( 18 ) for detecting an object by means of light is formed near the first area ( 16 ). When an object is detected in the first area ( 16 ) approaching the second area ( 18 ), the second area ( 18 ) is enabled. When an object is detected in the first area ( 16 ) moving in the direction away from the second area ( 18 ), the second area ( 18 ) is disabled.

1. A composite sensor for use with a door, comprising:
 radio wave or ultrasonic-wave detecting means for detecting the presence of an object and the direction of movement of the object in a first area along said door;  
 light detecting means for detecting a stationary object in a second area along and near said door;  
 enabling means for enabling, when said radio-wave or ultrasonic-wave detecting means detects an object approaching said door in said first area, said light detecting means to thereby make object detection in said second area possible; and  
 disabling means for disabling, when said radio-wave or ultrasonic-wave detecting means detects the movement of the object in said first area away from said door with the object detection in said second area made possible, said light detecting means so as to disable object detection in said second area.  
 
     
     
       2. An automatic door system for selectively opening and closing a door in response to a signal representative of the result of detection by said composite sensor according to  claim 1 . 
     
     
       3. A composite sensor for use with a door, comprising:
 radio wave or ultrasonic-wave detecting means for detecting the presence of an object and the direction of movement of the object in a first area along said door;  
 light detecting means for detecting a stationary object in a second area along and near said door; and  
 a parameter adjusting means for changing a parameter relating to object detection by said light detecting means in such a manner that said light detecting means does not detect a stationary object when said radio-wave or ultrasonic-wave detecting means detects an object moving in said first area away from said door, when said door is open.  
 
     
     
       4. The composite sensor according to  claim 3 , wherein said parameter adjusting means lowers a sensitivity of said light detecting means. 
     
     
       5. The composite sensor according to  claim 3 , wherein said light detecting means judges that no object is present when a received light amount representative signal from said light detecting means is outside an allowable range determined for a predetermined reference signal, and said parameter adjusting means changes said reference signal to said received light amount representative signal. 
     
     
       6. The composite sensor according to  claim 3 , wherein said light detecting means judges that no object is present when a received light amount representative signal from said light detecting means is outside an allowable range determined for a predetermined reference signal, and said parameter adjusting means changes said reference signal to said received light amount representative signal. 
     
     
       7. An automatic door system for selectively opening and closing a door in response to a signal representative of the result of detection by said composite sensor according to  claim 3 . 
     
     
       8. The composite sensor according to  claim 3 , wherein said parameter adjusting means changes detection control provided by said light detecting means to moving object detection, in which it is judged that an object is present when the amount of variations of said received light amount representative signal is more than a predetermined value.