| 摘要 |
A touch-sensing apparatus comprises a light transmissive panel, in which sheets of light are propagated by internal reflection between a touch surface and an opposite surface from an incoupling site to an outcoupling site. The touch-sensing apparatus is configured such that objects touching the touch surface cause a local attenuation of at least two sheets of light. A light sensor arrangement is optically connected to the outcoupling site to measure transmitted light energy. A data processor is connected to the light sensor arrangement and configured to execute a touch determination process. The process operates on at least oneprojection signal which is indicative of a spatial distribution of light within the outcoupling site. In the process, the projection signal(s) is/are processed for identification of signal profiles representing the attenuation (step 202). The signal profiles are used for identifying one or more candidate touch areas on the touch surface (step 1206´). The projection signal(s) is/are then processed to reconstruct a two-dimensional distribution of signal values locally within the one or more 1 candidate touch areas (step 1207), whereupon touch data for the or each object is determined by processing the reconstructed signal values within the candidate touch areas (step 1208). |
