Patent US 4,123,631

An improved touch actuated capacitance switch. A series of conductive touch pads are formed on one face of a dielectric material substrate plate. The touch pads are deposited by techniques which result in metallic films that are quite sensitive to damage by abrasion. To protect these pads, a protective overcoat is put over each touch pad, the overcoat obscuring no more than about seventy-percent of the total area of the touch pad. On the other face of the substrate plate are adhered a series of conductive sites, each site being in alignment across the thickness of the substrate plate with one of the touch pads. The conductive sites are then interconnected by a conductor network to give a predefined logic pattern.