Capacitance sensor and detector using same for detecting object being caught by door

Abstract

A capacitance sensor with a directionality characteristic in the direction of its detection surface is incorporated in a detector for detecting an object that may be feared to or about to be caught by a closing door such as a slide door of a vehicle. The capacitance sensor has a main body enclosing detection electrodes, an insulating material placed in between and a shield electrode serving to provide the directionality. A water-repellant finish is provided at least on a portion of the outer surface of the main body including the detection surface for preventing water drops from remaining or becoming larger. The detection surface may be unevenly shaped with protrusions for making it difficult for water drops to remain attached.

What is claimed is:  
     
         1 . A capacitance sensor having specified directionality, said capacitance sensor comprising: 
 detection electrodes;    an insulating material insulating said detection electrodes from each other;    a main body containing said detection electrodes and said insulating material and having a detection surface defined by said directionality; and    a water-repellant finish over at least a portion of said main body including said detection surface.    
     
     
         2 . The capacitance sensor of  claim 1  further comprising: 
 a shield electrode inside said main body, said shield electrode being open toward said detection surface, said detection electrodes being disposed inside said shield electrode; and  
 a protective cover covering said shield electrode and said detection electrodes.  
 
     
     
         3 . A capacitance sensor having specified directionality, said capacitance sensor comprising: 
 detection electrodes;    an insulating material insulating said detection electrodes from each other; and    a main body containing said detection electrodes and said insulating material and having a detection surface defined by said directionality, said detection surface having unevenness.    
     
     
         4 . The capacitance sensor of  claim 3  further comprising: 
 a shield electrode inside said main body, said shield electrode being open toward said detection surface, said detection electrodes being disposed inside said shield electrode; and  
 a protective cover covering said shield electrode and said detection electrodes.  
 
     
     
         5 . A detector for detecting an object being caught by a door, said detector comprising: 
 detection electrodes;    an insulating material insulating said detection electrodes from each other;    a main body provided on an open end part of said door, said main body containing said detection electrodes and said insulating material;    a sensor circuit which, together with said sensor main body, forms a capacitance sensor having specified directionality;    wherein said sensor main body includes a detection surface defined by said directionality and a water-repellant finish is provided over at least a portion of said sensor main body including said detection surface.    
     
     
         6 . The detector of  claim 5  further comprising: 
 a shield electrode inside said main body, said shield electrode being open toward said detection surface, said detection electrodes being disposed inside said shield electrode; and  
 a protective cover covering said shield electrode and said detection electrodes.  
 
     
     
         7 . A detector for detecting an object being caught by a door, said detector comprising: 
 detection electrodes;    an insulating material insulating said detection electrodes from each other;    a main body provided on an open end part of said door, said main body containing said detection electrodes and said insulating material; and    a sensor circuit which, together with said sensor main body, forms a capacitance sensor having specified directionality;    wherein said sensor main body includes an uneven detection surface defined by said directionality.    
     
     
         8 . The detector of  claim 7  further comprising: 
 a shield electrode inside said main body, said shield electrode being open toward said detection surface, said detection electrodes being disposed inside said shield electrode; and  
 a protective cover covering said shield electrode and said detection electrodes.  
 
     
     
         9 . A detector for detecting an object being caught by a door, said detector comprising: 
 detection electrodes;    an insulating material insulating said detection electrodes from each other;    a main body provided on an open end part of said door, said main body containing said detection electrodes and said insulating material;    a sensor circuit which, together with said sensor main body, forms a capacitance sensor having specified directionality; and    means for grounding said door;    wherein said sensor main body includes a detection surface defined by said directionality and said detector further comprised means for grounding said door.    
     
     
         10 . The detector of  claim 9  further comprising: 
 a shield electrode inside said main body, said shield electrode being open toward said detection surface, said detection electrodes being disposed inside said shield electrode; and  
 a protective cover covering said shield electrode and said detection electrodes.  
 
     
     
         11 . A detector for detecting an object being caught by a door, said detector comprising: 
 detection electrodes;    an insulating material insulating said detection electrodes from each other;    a main body provided on an open end part of said door, said main body containing said detection electrodes and said insulating material;    a sensor circuit which, together with said sensor main body, forms a capacitance sensor having specified directionality;    wherein said sensor main body includes a detection surface defined by said directionality, said detection surface being at a position farther protruding from an open end part of said door.    
     
     
         12 . The detector of  claim 11  further comprising: 
 a shield electrode inside said main body, said shield electrode being open toward said detection surface, said detection electrodes being disposed inside said shield electrode; and  
 a protective cover covering said shield electrode and said detection electrodes.