Patent ID: 6236391
Filing Date: 2001-05-22
Classification: G06F

Abstract:
A touch panel provided with a glass substrate as a propagation medium for Rayleigh waves and which is used for detecting the coordinate data on a touching position, wherein the composition of the glass substrate comprises SiO.sub.2 as the main component, comprises at least 1% by weight of Na.sub.2 O and comprises additional components that prevent said SiO.sub.2 from forming a regular crystalline lattice by disruption of Si--O--Si covalent links, and wherein said added components provide sufficiently strong alternate links through strong ionic bonding, alternate covalent bonding, or steric constraints to produce an attenuation coefficient of less than or equal to about 0.51 dB/cm as determined at the substrate surface for 5.53 MHZ Rayleigh waves as measured by the slope of a plot of amplitude versus distance for a signal through a pair of facing 0.5-inch wide wedge transducers mounted on a sample of the glass type under test having sufficient thickness to support Rayleigh wave propagation.