Acceleration sensor

Abstract

An acceleration sensor includes a piezoelectric single-plate having a weight part and a detection part. The piezoelectric single-plate is, for example, an X-cut plate of LiNbO 3 .

1 - 18 . (Canceled).  
   
   
       19 . An acceleration sensor comprising: 
 a piezoelectric single-plate having a weight part and a detection part;    a detection electrode provided on a first surface of the piezoelectric single-plate, an electric signal caused by inertia force exerted onto the weight part resulting from acceleration being output via the detection electrode; and    a ground electrode provided on a second surface of the piezoelectric single-plate opposite to the first surface;    wherein the detection electrodes includes two electrode parts arranged side by side in a direction perpendicular to another direction in which the acceleration is applied to the acceleration sensor.    
   
   
       20 . The acceleration sensor as claimed in  claim 19 , wherein the detection electrode comprises two electrode parts arranged side by side in a direction in which the acceleration is applied to the acceleration sensor.  
   
   
       21 . The acceleration sensor as claimed in  claim 19 , wherein the piezoelectric single-plate has a supporting position which does not include a center of gravity of the piezoelectric single-plate.  
   
   
       22 . The acceleration sensor as claimed in  claim 19 , wherein the piezoelectric single-plate has a supporting position which includes a center of gravity of the piezoelectric single-plate.  
   
   
       23 . The acceleration sensor as claimed in  claim 19 , wherein the piezoelectric single-plate has a supporting position with which the detection electrode overlaps.  
   
   
       24 . The acceleration sensor as claimed in  claim 19 , wherein the piezoelectric single-plate is an X-cut plate of LiNbO3.  
   
   
       25 . The acceleration sensor as claimed in  claim 19 , further comprising another ground electrode provided on the first surface of the piezoelectric single-plate.  
   
   
       26 . The acceleration sensor as claimed in  claim 19 , wherein the ground electrode is thicker than the detection electrode.  
   
   
       27 . The acceleration sensor as claimed in  claim 19 , wherein the detection electrode and the ground electrodes have respective densities that are greater than a density of the piezoelectric single plate.  
   
   
       28 . The acceleration sensor as claimed in  claim 25 , further comprising an electrically conductive resin that electrically connects the ground electrode and said another ground electrode.  
   
   
       29 . The acceleration sensor as claimed in  claim 25 , further comprising an insulating resin provided in a groove that separates the detection electrode and said another ground electrode from each other.  
   
   
       30 . The acceleration sensor as claimed in  claim 19 , further comprising: 
 a package to which the piezoelectric single-plate is attached;    an electrode terminal provided on the package; and    an electrically conductive adhesive agent which attaches the piezoelectric single-plate to the package and electrically connects the detection electrode and the electrode terminal.    
   
   
       31 . The acceleration sensor as claimed in  claim 19 , further comprising: 
 a package to which the piezoelectric single-plate is attached;    an electrode terminal provided on the package; and    an anisotropic electrically conductive adhesive agent which attaches the piezoelectric single-plate to the package and electrically connects the detection electrode and the electrode terminal.    
   
   
       32 . The acceleration sensor as claimed in  claim 19 , further comprising a flexible printed-circuit cable to which the detection electrode and the ground electrode are connected.  
   
   
       33 . The acceleration sensor as claimed in  claim 19 , further comprising wires connecting the detection electrode and the ground electrodes to electrode terminals formed on a member by which the piezoelectric single-plate is supported.  
   
   
       34 . The acceleration sensor as claimed in  claim 19 , further comprising: 
 a package which accommodates the piezoelectric single-plate;    and an electrically conductive resin which electrically connects the ground electrode to an electrode terminal provided on the package.    
   
   
       35 . The acceleration sensor as claimed in  claim 19 , further comprising: 
 an electric circuit that processes an electric signal output from the piezoelectric single-plate; and    a package which accommodates the electric circuit and the piezoelectric single-plate    
   
   
       36 . The acceleration sensor as claimed in  claim 35 , wherein the package is provided with a guide base positioning and supporting the piezoelectric single-plate.  
   
   
       37 . The acceleration sensor as claimed in  claim 35 , wherein the electric circuit is located below the piezoelectric single-plate.