US 7,492,358 B2
Resistive scanning grid touch panel
Hye S. Chi, Raleigh, N.C. (US); Timothy W. Crockett, Raleigh, N.C. (US); and Albert V. Makley, Raleigh, N.C. (US)
Assigned to International Business Machines Corporation, Armonk, N.Y. (US)
Filed on Jun. 15, 2004, as Appl. No. 10/867,830.
Prior Publication US 2005/0275634 A1, Dec. 15, 2005
Int. Cl. G06F 3/045 (2006.01); G06F 3/041 (2006.01)
U.S. Cl. 345—173  [178/18.05] 5 Claims
OG exemplary drawing
 
1. A resistive touch panel, comprising:
a first sheet, comprising a plurality of independent stripes of a first resistive coating, the first sheet being transparent;
a second sheet, comprising a second resistive coating separated from the first sheet by a plurality of insulator dots, wherein a voltage difference exists between the second resistive coating and the plurality of independent stripes, wherein the plurality of independent stripes and the second resistive coating form a plurality of independent overlapping regions; and
a controller, coupled to the first sheet and the second sheet, the controller configured to detect a contact between the first sheet and the second sheet in at least one of the plurality of independent overlapping regions and scans the plurality of independent stripes and the second resistive coating to determine a position of the contact, wherein the scanning includes:
switching between applying a current to each of the plurality of independent stripes and monitoring the second sheet and applying the current to the second sheet and monitoring each of the plurality of independent stripes,
determining the position of the contact in a first direction by measuring a first voltage difference between a first and a second side of each of the plurality of independent stripes, when the current is applied to the first sheet, and
determining the position of the contact in a second direction by measuring a second voltage difference between a first and a second side of the second sheet, when the current is applied to the second sheet.