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Pressure Controlled Resistance Matrix

IP.com Disclosure Number: IPCOM000096582D
Original Publication Date: 1963-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Einolf, CW: AUTHOR [+2]

Abstract

Pressure controlled resistance changes in selected areas of a pressure sensitive resistance layer, physically positioned between coordinate conductors of a resistance matrix, allow handwriting with a stylus to be converted to digital signals by a scan of the matrix.

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Pressure Controlled Resistance Matrix

Pressure controlled resistance changes in selected areas of a pressure sensitive resistance layer, physically positioned between coordinate conductors of a resistance matrix, allow handwriting with a stylus to be converted to digital signals by a scan of the matrix.

The matrix comprises pressure sensitive resistance layer 1 which is sandwiched between horizontal conductors 2 and vertical conductors 3 of the matrix. Vertical conductors 3 are printed on ceramic base plate 4. Conductors 2 are printed upon face sheet 5 which is a flexible tough sheet of insulating polyester plastic.

At rest, the resistance across each intersection of the matrix is a finite value, This is established as the 0 bit value for the intersection, The resistance of selected intersections is lowered by pressure as from stylus 6. Such deforms face sheet 5 and applies pressure to layer 1 locally. Deformation at an intersection lowers the resistance of the intersection. A faster scan of the matrix tests each intersection by applying electrical potential between the selected horizontal and vertical conductor and measuring the resistance value of the intersection. A high resistance value is a 0. A low resistance value is a 1. Scan speed must be fast enough to follow the excursions of stylus 6. This is because the resistance layer recovers in a short time after the pressure is removed,

A hard copy on a sheet of paper can be made, The paper is placed over face s...