Abstract: A light guide assembly (2) for use in a touch sensitive area (3) of an optical touch sensing device (1) for touch screens is configured to receive light, to allow the light thereby received to propagate in the light guide assembly, and to deliver the light thereby propagated in the light guide assembly further out of the light guide assembly. The light guide assembly comprises a plurality of light guide stripes (4, 4? 5) for controlling the light propagation, and an interaction arrangement (27; 17; 21) configured to define at least one restricted interaction area (11) within the touch sensitive area for interaction between the light and the external object. The optical touch sensing device is configured to detect the presence of an external object (10) on the basis of changes in the light delivered further out of the light guide assembly due to interaction of the light with the external object.

Abstract: A light guide assembly (2) for use in a touch sensitive area (3) of an optical touch sensing device (1) for touch screens is configured to receive light, to allow the light thereby received to propagate in the light guide assembly, and to deliver the light thereby propagated in the light guide assembly further out of the light guide assembly. The light guide assembly comprises a plurality of light guide stripes (4, 5) for controlling the propagation of light. The optical touch sensing device is configured to detect the presence of an external object (10) on the basis of changes in the light delivered further out of the light guide assembly due to interaction of the light with the external object.