Optical incoupling for touch-sensitive systems

摘要

A touch-sensitive apparatus comprises a light transmissive panel, an illumination arrangement and a detection arrangement. The illumination arrangement is configured to couple light into the panel via an incoupling site such that the light propagates by total internal reflection in opposite top and bottom surfaces of the panel and such that an object touching the top or bottom surface causes a change in the propagating light. The detection arrangement comprises a light detector arranged to detect the change in the propagating light. A compact and robust incoupling site is defined by a sheet-like micro-structured surface portion which is fixedly arranged on one of the top and bottom surfaces and configured to transmit light having an angle of incidence that enables light propagation by TIR inside the panel.

主权项

1. A touch-sensitive apparatus, comprising:
a light transmissive panel that defines parallel top and bottom surfaces; an illumination arrangement configured to couple light into the light transmissive panel via an incoupling site such that the light propagates by total internal reflection in at least one of the top and bottom surfaces, and such that an object touching said at least one of the top and bottom surfaces causes a change in the propagating light; a detection arrangement including a light detector configured to detect said change in the propagating light; wherein the incoupling site has an elongated structure and is arranged at a peripheral edge surface of the light transmissive panel; and wherein the incoupling site is defined by a sheet-like micro-structured surface portion, which is fixedly arranged on one of the top and bottom surfaces, the sheet-like micro-structured surface portion configured to transmit light having an angle of incidence that enables light propagation by total internal reflection inside the light transmissive panel.