Gary Lee Barrett

US Patent:

50417010, Aug 20, 1991

Filed:

Mar 15, 1988

Appl. No.:

7/168292

Inventors:

Andrew L. Wolfe - Pittsburgh PA
Gary L. Barrett - Austin TX

Assignee:

Carroll Touch Incorporated - Round Rock TX

International Classification:

G08C 2100

US Classification:

178 18

Abstract:

An edge linearization device for linearizing the electric fields in a resistive surface is described. A plurality of electrodes are disposed on the perimeter of an area on a surface having a substantially uniform resistivity. The device utilizes the geometry of the spaces between adjacent conductive elements to provide resistive elements. At least one of the electrodes has an extension. The extension or extensions of the electrodes are progressively inwardly displaced into the area from the perimeter so that there is at least one center-most extension on a first portion of said perimeter and also on a second, opposing portion of said perimeter. In a preferred embodiment, the invention utilizes a surface with a substantially rectangular area having four sides and four corners. Disposed along the sides are a plurality of electrodes and corner electrodes and disposed in the corners of the surface are corner connectors. The use of T-shaped extensions of the electrodes on such a surface is also disclosed.