Patent ID: 9285623
Filing Date: 2016-03-15
CPC Classification: G02F,G06F

Claim Text:
1. A touch system for sensing a touch event, comprising: a planar transparent sheet having opposite upper and lower surfaces and an index of refraction n.sub.2; at least one light source that emits light, the light source operably arranged in optical communication with the planar transparent sheet to cause the light to travel within the planar transparent sheet by total-internal reflection (TIR); at least one detector operably arranged to detect the TIR-traveling light and to detect an amount of attenuation in the TIR-traveling light cause by the touch event; a display unit having an upper surface; and an interface layer contacting the lower surface of the planar transparent sheet and the upper surface of the display unit, wherein the interface layer has a refractive index n.sub.1, wherein n.sub.1<n.sub.2, and having a thickness of equal to or greater than 1 micron.