Patent ID: 8847925

Claim:
An arrangement for a user input device, such as a touchscreen or a touchpad, the arrangement comprising: a substrate, such as an optically substantially transparent flex film or a multilayer film, said substrate comprising support electronics, such as printed, optionally roll-to-roll processed, electronics including a number of printed conductors, for providing power, control and/or communications connection to further electronic components, a number of emitters and detectors arranged to said substrate into contact with the support electronics, for emitting and detecting light, respectively, and a lightguide laminated onto the substrate such that said emitters and detectors are optically coupled to the lightguide material, the properties of the lightguide including the refractive index of the lightguide material being selected and the emitters and detectors being configured so as to enable, when in use, total internal reflection (TIR) type propagation of light within the lightguide between the emitters and detectors, and recognition of a touch on the basis of a drop in the TIR performance as determined from the detected light, said drop including a FTIR (frustrated TIR)-induced drop in the light intensity level, as captured by one or more detectors, in contrast to a predetermined or adaptively determined basic reception level during a TIR condition, and further wherein the lightguide surface that faces the substrate has been provided, prior to being laminated onto the substrate, with a recess or hole accommodating at least portion of at least one emitter or detector positioned therein.