Touch screen with electrodes including linear and branched portions

Abstract

In a touch screen, a lower electrode is insulated from an upper electrode by an insulation film. A column direction wire of the upper electrode includes a first linear portion which extends in a row direction, and first branch portions which are branched from the first linear portion. A row direction wire of the lower electrode includes a second linear portion which extends in a column direction, and second branch portions which are branched from the second linear portion. The second linear portion three-dimensionally intersects the first linear portion, yet does not three-dimensionally intersect first branch portions. A rim portion of each of second branch portions includes a portion parallel along an outline of the first linear portion or first branch portions, yet does not include a portion parallel along an outline of the second linear portion. At each of second branch portions, a cavity portion is formed.

What is claimed is: 
     
       1. A touch screen comprising:
 a substrate which includes a main surface; 
 a first electrode which is disposed on said main surface and includes a plurality of first wires, said plurality of first wires being detection wires, and each of the first wires including a first linear portion and a plurality of first branch portions, said first linear portion extending in a first direction, said plurality of first branch portions being branched from said first linear portion; 
 an insulation film which is disposed on said main surface; and 
 a second electrode which is disposed on said main surface, is at least partially insulated from said first electrode by said insulation film, and includes a plurality of second wires, said plurality of second wires being excitation wires, and each of the second wires including a second linear portion and a plurality of second branch portions, said second linear portion extending in a second direction which is not parallel to said first direction, said plurality of second branch portions being branched from said second linear portion, said second linear portion three-dimensionally intersecting said first linear portion and not three-dimensionally intersecting said plurality of first branch portions, said plurality of second branch portions each including a rim portion, a part of said second linear portion and said rim portion surrounding forming a border that surrounds a cavity portion formed at each of said plurality of second branch portions, said rim portion including a portion parallel along an outline of said first linear portion or said plurality of first branch portions and not including a portion parallel along an outline of said second linear portion, said rim portion including a first portion parallel along said first linear portion when seen in a plan view in a normal direction of said main surface. 
 
     
     
       2. The touch screen according to  claim 1 , wherein said rim portion further includes
 a first portion, and 
 a second portion which conducts with said first portion and is partitioned from said first portion by said cavity portion when seen from said plurality of first branch portions. 
 
     
     
       3. The touch screen according to  claim 1 , wherein
 each of said plurality of first branch portions includes a first extended portion extending in said second direction and having a first width, and 
 each of said plurality of second branch portions includes a second extended portion extending in said second direction and having a second width identical to said first width. 
 
     
     
       4. The touch screen according to  claim 1 , wherein
 each of said plurality of first wires includes a first layer made of indium tin oxide, a metal wire material or an alloy wire material, and 
 each of said plurality of second wires includes a second layer made of indium tin oxide, a metal wire material or an alloy wire material. 
 
     
     
       5. The touch screen according to  claim 1 , further comprising a dummy pattern which is made of an insulation body and fills said cavity portion and a gap between said first electrode and said second electrode. 
     
     
       6. A touch screen comprising:
 a substrate which includes a main surface; 
 a first electrode which is disposed on said main surface and includes a plurality of first wires, said plurality of first wires being excitation wires, and each of the first wires including a first linear portion and a plurality of first branch portions, said first linear portion extending in a first direction, said plurality of first branch portions being branched from said first linear portion; 
 an insulation film which is disposed on said main surface; and 
 a second electrode which is disposed on said main surface, is at least partially insulated from said first electrode by said insulation film, and includes a plurality of second wires, said plurality of second wires being detection wires, and each of the second wires including a second linear portion and a plurality of second branch portions, said second linear portion extending in a second direction which is not parallel to said first direction, said plurality of second branch portions being branched from said second linear portion, said second linear portion three-dimensionally intersecting said first linear portion and not three-dimensionally intersecting said plurality of first branch portions, said plurality of second branch portions each including a rim portion, a part of said second linear portion and said rim portion surrounding forming a border that surrounds a cavity portion formed at each of said plurality of second branch portions, said rim portion including a first portion parallel along an outline of said first linear portion or and including a second portion parallel along one of said plurality of first branch portions and not including a portion parallel along an outline of adjacent to said second linear portion other than the part of said second linear portion when seen in a plan view in a normal direction of said main surface. 
 
     
     
       7. The touch screen according to  claim 6 , wherein said rim portion includes
 a first portion, and   a second portion which conducts with said first portion and is partitioned from said first portion by said cavity portion when seen from said plurality of first branch portions.   
     
     
       8. The touch screen according to  claim 6 , wherein
 each of said plurality of first branch portions includes a first extended portion extending in said second direcion and having a first width, and 
 each of said plurality of second branch portions includes a second extended portion extending in said second direction and having a second width identical to said first width. 
 
     
     
       9. The touch screen according to  claim 6 , wherein
 each of said plurality of first wires includes a first layer made of indium tin oxide, a metal wire material or an alloy wire material, and 
 each of said plurality of second wires includes a second layer made of indium tin oxide, a metal wire material or an alloy wire material. 
 
     
     
       10. The touch screen according to  claim 6 , further comprising a dummy pattern which is made of an insulation body and fills said cavity portion and a gap between said first electrode and said second electrode. 
     
     
       11. The touch screen according to claim 1, wherein said plurality of first wires are detection wires.  
     
     
       12. The touch screen according to claim 1, wherein said plurality of second wires are excitation wires.  
     
     
       13. The touch screen according to claim 1, wherein said rim portion does not include a portion directly adjacent to said second linear portion other than the part of said second linear portion when seen in a plan view in a normal direction of said main surface.  
     
     
       14. The touch screen according to claim 13, wherein a first branch portion of said plurality of first branch portions includes a first edge that is substantially parallel to said first linear portion.  
     
     
       15. The touch screen according to claim 14, wherein said first branch portion further includes a second edge that is substantially parallel to said second linear portion.  
     
     
       16. The touch screen according to claim 13, wherein a first branch portion of said plurality of first branch portions includes a first edge that is substantially parallel to said second linear portion.  
     
     
       17. The touch screen according to claim 1, wherein a first branch portion of said plurality of first branch portions includes a first edge that is substantially parallel to said first linear portion.  
     
     
       18. The touch screen according to claim 17, wherein said first branch portion further includes a second edge that is substantially parallel to said second linear portion.  
     
     
       19. The touch screen according to claim 1, wherein a first branch portion of said plurality of first branch portions includes a first edge that is substantially parallel to said second linear portion.  
     
     
       20. The touch screen according to claim 6, wherein a first branch portion of said plurality of first branch portions does not form a rim that has a cavity.  
     
     
       21. The touch screen according to claim 6, wherein said second linear portion is disposed between said plurality of first branch portions.