Touch detection device and liquid crystal display device

Abstract

A touch detection device is provided and includes a plurality of driving electrodes for detecting an external proximity object in a detection area; a first driving circuit to drive the plurality of driving electrodes; and a second driving circuit to drive the plurality of driving electrodes, wherein the first driving circuit and the second driving circuit sandwich the detection area in a plan view.

The invention is claimed as follows: 
     
         1 . A touch detection device comprising:
 a plurality of driving electrodes for detecting an external proximity object in a detection area;   a first driving circuit to drive the plurality of driving electrodes; and   a second driving circuit to drive the plurality of driving electrodes, wherein   the first driving circuit and the second driving circuit sandwich the detection area in a plan view.   
     
     
         2 . The touch detection device according to  claim 1 , wherein
 each of the first driving circuit and the second driving circuit comprises:
 a first voltage line; 
 a second voltage line; 
 a third voltage line; and 
 a switching circuit for electrically connecting the plurality of driving electrodes and the first voltage line, the second voltage line, or the third voltage line. 
   
     
     
         3 . The touch detection device according to  claim 1 , wherein
 each of the first driving circuit and the second driving circuit comprises:
 a first voltage line extending in a first direction; 
 a second voltage line extending in the first direction; 
 a third voltage line extending in the first direction, the third voltage line being narrower in than the first voltage line and the second voltage line in width; and 
 a switching circuit for electrically connecting the plurality of driving electrodes and the first voltage line, the second voltage line, or the third voltage line. 
   
     
     
         4 . The touch detection device according to  claim 2 ,
 wherein a first voltage applied to the first voltage line, a second voltage applied to the second voltage line different from the first voltage, and a third voltage applied to the third voltage line different from the first and the second voltages, are direct-current voltage.   
     
     
         5 . The touch detection device according to  claim 3 ,
 wherein a first voltage applied to the first voltage line, a second voltage applied to the second voltage line different from the first voltage, and a third voltage applied to the third voltage line different from the first and the second voltages, are direct-current voltage.   
     
     
         6 . The touch detection device according to  claim 2 ,
 wherein the plurality of driving electrodes includes a selected driving electrode and an unselected driving electrode,   wherein the switching circuit alternately electrically connects the selected driving electrode to the first voltage line and the second voltage line in a period of detecting the external proximity object,   wherein the switching circuit electrically connects the unselected driving electrode to the third voltage line in the period of detecting the external proximity object.   
     
     
         7 . The touch detection device according to  claim 3 ,
 wherein the plurality of driving electrodes includes a selected driving electrode and an unselected driving electrode,   wherein the switching circuit alternately electrically connects the selected driving electrode to the first voltage line and the second voltage line in a period of detecting the external proximity object,   wherein the switching circuit electrically connects the unselected driving electrode to the third voltage line in the period of detecting the external proximity object.   
     
     
         8 . The touch detection device according to  claim 6 ,
 wherein the switching circuit sequentially shifts the selected driving electrode among the plurality of driving electrodes in the second direction.   
     
     
         9 . The touch detection device according to  claim 7 ,
 wherein the switching circuit sequentially shifts the selected driving electrode among the plurality of driving electrodes in the second direction.   
     
     
         10 . The touch detection device according to  claim 5 ,
 wherein the second voltage and the third voltage have the same voltage value, and the first voltage is different from the second voltage and the third voltage.   
     
     
         11 . A liquid crystal display device comprising:
 a first substrate including a plurality of pixel electrodes, a plurality of common electrodes opposed to the plurality of pixel electrodes for display and touch detection, in a display area;   a second substrate opposed to the first substrate with a liquid crystal therebetween;   a first driving circuit, on the first substrate, to drive the plurality of common electrodes; and   a second driving circuit, on the first substrate, to drive the plurality of common electrodes, wherein
 the first driving circuit and the second driving circuit sandwich the display area in a plan view. 
   
     
     
         12 . The liquid crystal display device according to  claim 11 , wherein
 each of the first driving circuit and the second driving circuit comprises:
 a first voltage line; 
 a second voltage line; 
 a third voltage line; and 
 a switching circuit for electrically connecting the plurality of common electrodes and the first voltage line, the second voltage line, or the third voltage line. 
   
     
     
         13 . The liquid crystal display device according to  claim 11 , wherein
 each of the first driving circuit and the second driving circuit comprises:
 a first voltage line extending in a first direction; 
 a second voltage line extending in the first direction; 
 a third voltage line extending in the first direction, the third voltage line being narrower in than the first voltage line and the second voltage line in width; and 
 a switching circuit for electrically connecting the plurality of common electrodes and the first voltage line, the second voltage line, or the third voltage line. 
   
     
     
         14 . The liquid crystal display device according to  claim 12 ,
 wherein a first voltage applied to the first voltage line, a second voltage applied to the second voltage line different from the first voltage, and a third voltage applied to the third voltage line different from the first and the second voltages, are direct-current voltage.   
     
     
         15 . The liquid crystal display device according to  claim 13 ,
 wherein a first voltage applied to the first voltage line, a second voltage applied to the second voltage line different from the first voltage, and a third voltage applied to the third voltage line different from the first and the second voltages, are direct-current voltage.   
     
     
         16 . The liquid crystal display device according to  claim 12 ,
 wherein the plurality of common electrodes includes a selected common electrode and an unselected common electrode,   wherein the switching circuit alternately electrically connects the selected common electrode to the first voltage line and the second voltage line in a period of detecting the external proximity object,   wherein the switching circuit electrically connects the unselected common electrode to the third voltage line in the period of detecting the external proximity object.   
     
     
         17 . The liquid crystal display device according to  claim 13 ,
 wherein the plurality of driving electrodes includes a selected common electrode and an unselected common electrode,   wherein the switching circuit alternately electrically connects the selected common electrode to the first voltage line and the second voltage line in a period of detecting the external proximity object,   wherein the switching circuit electrically connects the unselected common electrode to the third voltage line in the period of detecting the external proximity object.   
     
     
         18 . The liquid crystal display device according to  claim 16 ,
 wherein the switching circuit sequentially shifts the selected common electrode among the plurality of common electrodes in the second direction.   
     
     
         19 . The liquid crystal display device according to  claim 17 ,
 wherein the switching circuit sequentially shifts the selected common electrode among the plurality of common electrodes in the second direction.   
     
     
         20 . The liquid crystal display device according to  claim 15 ,
 wherein the second voltage and the third voltage have the same voltage value, and the first voltage is different from the second voltage and the third voltage.