Capacitance type displacement detection apparatus

Abstract

A transmission electrode 10 and a detection electrode 12 are placed in an electrode section of a sensor and are capacity-coupled with a reception electrode placed on an opposed scale. Capacity change between the transmission electrode 10 and the reception electrode caused by displacement is detected with the detection electrode 12 . A plurality of signals different in phase are supplied to the transmission electrode 10 . The signal lines are wired like a zigzag using an upper layer and a lower layer and the distances between the signal lines and the detection electrode 12 are made substantially equal for making uniform the crosstalk amounts relative to the detection electrode 12.

What is claimed is:  
     
         1 . A capacitance type displacement detection apparatus having a transmission electrode and a detection electrode formed on one scale and capacity-coupled with a reception electrode formed on the other scale opposite to the one scale, said apparatus comprising: 
 a plurality of transmission signal lines disposed on the one scale at substantially equal distance from the detection electrode for supplying signals to the transmission electrode.    
     
     
         2 . The capacitance type displacement detection apparatus as claimed in    claim 1   , wherein the plurality of transmission signal lines are disposed on a plurality of wiring layers.  
     
     
         3 . The capacitance type displacement detection apparatus as claimed in    claim 1   , wherein the distances between the respective transmission signal lines and the detection electrode are substantially equal.  
     
     
         4 . The capacitance type displacement detection apparatus as claimed in    claim 2   , wherein the distances between the respective transmission signal lines and the detection electrode are substantially equal.  
     
     
         5 . The capacitance type displacement detection apparatus as claimed in    claim 1   , wherein said capacitance type displacement detection apparatus has a plurality of detection electrodes and the plurality of the transmission signal lines are disposed at substantially equal distance from each of the detection electrodes.  
     
     
         6 . The capacitance type displacement detection apparatus as claimed in    claim 2   , wherein said capacitance type displacement detection apparatus has a plurality of detection electrodes and the plurality of the transmission signal lines are disposed at substantially equal distance from each of the detection electrodes.  
     
     
         7 . The capacitance type displacement detection apparatus as claimed in    claim 2   , further comprising: 
 at least one insulating layer disposed between adjacent wiring layers.    
     
     
         8 . The capacitance type displacement detection apparatus as claimed in    claim 1   , wherein said transmission signal lines has a differential relationship and are disposed adjacently to each other with respect to the detection electrode.  
     
     
         9 . A capacitance type displacement detection apparatus having a transmission electrode and a detection electrode formed on one scale and capacity-coupled with a reception electrode formed on the other scale opposite to the one scale, said apparatus comprising: 
 a plurality of transmission signal lines disposed on the one scale for supplying signals to the transmission electrode, the transmission signal lines having a differential relationship and disposed adjacently to each other with respect to the detection electrode.    
     
     
         10 . The capacitance type displacement detection apparatus as claimed in    claim 9   , further comprising: 
 a switch portion for changing a wiring order of said transmission signal lines having the differential relationship and disposed adjacently to each other with respect to the detection electrode,    wherein each of said transmission signal lines is connected to a predetermined position of the transmission electrode.    
     
     
         11 . A capacitance type displacement detection apparatus having a transmission electrode group and a detection electrode group formed on one scale and capacity-coupled with a reception electrode formed on the other scale opposite to the one scale, said apparatus comprising: 
 a transmission signal line group for supplying signals to the transmission electrode group, said transmission signal line group having at least two transmission signal lines and disposed on a first wiring layer; and    a detection signal line group for transferring signals from the detection electrode group, said detection signal line group having at least two detection signal lines and disposed on a second wiring layer different from the first wiring layer, the detection signal lines having a differential relationship and disposed at substantially equal distance from the transmission signal line group.    
     
     
         12 . The capacitance type displacement detection apparatus as claimed in    claim 11   , further comprising: 
 an electromagnetic shielding layer formed between the first wiring layer and the second wiring layer.    
     
     
         13 . The capacitance type displacement detection apparatus as claimed in    claim 11   , wherein the detection signal line group is disposed on a plurality of wiring layers.  
     
     
         14 . The capacitance type displacement detection apparatus as claimed in    claim 13   , wherein the detection signal lines having one differential relationship are disposed on one wiring layer and the detect ion signal lines having the other differential relationship are disposed on the other wiring layer.  
     
     
         15 . The capacitance type displacement detection apparatus as claimed in    claim 13   , wherein the detection signal lines are respectively disposed on different wiring layers.  
     
     
         16 . A capacitance type displacement detection apparatus having a transmission electrode group and a detection electrode formed on one scale and capacity-coupled with a reception electrode formed on the other scale opposite to the one scale, said apparatus comprising: 
 a transmission signal line group for supplying signals to the transmission electrode group, said transmission signal line group including at least two transmission signal lines having a differential relationship and disposed on a first wiring layer; and    a detection signal line for transferring a signal from the detection electrode, said detection signal line disposed on a second wiring layer different from the first wiring layer at substantially equal distance from the transmission signal lines having the differential relationship.    
     
     
         17 . The capacitance type displacement detection apparatus as claimed in    claim 16   , further comprising: 
 an electromagnetic shielding layer formed between the first wiring layer and the second wiring layer.