Simplified touch tablet data device

摘要

A touch tablet is provided containing two sheets of insulating material each of which contains a plurality of spaced apart conductive lines. A resistive strip on each sheet contacts and connects electrically one end of each of the plurality of conductive lines on that sheet. Each resistive strip functions as a potentiometer. Mounted between the two sheets and spaced apart therefrom is a conductive middle sheet. The first and second sheets are mounted such that the first and second sets of a plurality of conductive lines on these sheets are orthogonal to each other. A user presses on one of the two sheets to bring all three sheets into contact. The impedence of each potentiometer is a function of the contact point. The potentiometer is used as part of an RC circuit to provide a variable time constant representative of the coordinate of the contact point.