See-through digitizer with clear conductive grid

In a combined display and cordless electromagnetic digitizing input device for a computer having a graphics display panel with a viewing surface and a back surface opposite the viewing surface, and a backlighting panel disposed adjacent said digitizing input device for backlighting said graphics display panel through said digitizing input device, a transparent grid wire assembly for electromagnetic positional determination of a stylus in a coordinate system associated with the display panel comprising:

• a) a first grid of parallel transparent conductors including means for connection to electromagnetic digitizing electronics to sense the location of the stylus in a first axis of the coordinate system disposed over the back surface, said first grid of parallel transparent conductors comprising a first flexible transparent substrate carrying a plurality of first transparent indium tin oxide conductors thereon;
• b) a second grid of parallel transparent conductors including means for connection to said electromagnetic digitizing electronics to sense the location of the stylus in a second axis of the coordinate system disposed over said first grid of parallel transparent conductors electrically insulated therefrom and perpendicular thereto, said second grid of parallel transparent conductors comprising a second flexible transparent substrate carrying a plurality of second transparent indium tin oxide conductors thereon;
• and,
• c) a sheet of a transparent conductive material connected to ground potential disposed over said second grid of parallel transparent conductors and adjacent to the backlighting panel for shielding the electrostatic interference.

In a combined display and cordless electromagnetic digitizing input device for a computer having a graphics display panel with a viewing surface and a back surface opposite the viewing surface, a transparent grid wire assembly to be positioned over the back surface for subsequent electromagnetic positional determination of a stylus in a coordinate system associated with the display panel comprising:

• a) a first flexible transparent substrate disposed over the back surface, carrying a plurality of first transparent indium tin oxide conductors thereon comprising a first grid of parallel transparent conductors, and including means for connection to electromagnetic digitizing electronics to sense the location of the stylus in a first axis of the coordinate system;
• b) a second flexible transparent substrate adhesively attached to said first flexible transparent substrate, carrying a plurality of second transparent indium tin oxide conductors thereon comprising a second grid of parallel transparent conductors perpendicular to said first grid of parallel transparent conductors, and including means for connection to said electromagnetic digitizing electronics to sense the location of the stylus in a second axis of the coordinate system;
• and,
• c) a sheet of a transparent conductive material connected to ground potential disposed over said second grid of parallel transparent conductors for shielding the electrostatic interference whereby backlighting of the graphics display panel by a backlighting panel takes place through said sheet of a transparent conductive material, said first flexible transparent substrate, and said second flexible transparent substrate.