PERFORMANCE MONITORING AND CORRECTION IN A TOUCH-SENSITIVE APPARATUS

摘要

Touch sensitivity is enabled using a touch system that comprises a panel configured to conduct signals, e.g. by TIR, along detection lines across a touch surface. A signal processor operates in a sequence of repetitions to: generate data samples that represent detected signal energy on the actual detection lines; generate based on the data samples, an interpolated sinogram comprising interpolation samples that represent fictitious detection lines which have a desired location on the touch surface; and reconstruct a signal interaction pattern for the touch surface based on the interpolated sinogram. The signal processor implements an error correction to counteract the influence of a change in validity status for a data sample among the data samples, by identifying interpolation samples affected by the change in validity status, and by setting each identified interpolation sample to a value that maintains a relative signal transmission of the fictitious detection line from a former repetition.

主权项

1. A method of enabling touch determination based on an output signal from a touch-sensitive apparatus, the touch-sensitive apparatus comprising a panel configured to conduct signals from a plurality of peripheral incoupling points to a plurality of peripheral outcoupling points, thereby defining actual detection lines that extend across a surface portion of the panel between pairs of incoupling and outcoupling points, at least one signal generator coupled to the incoupling points to generate the signals, and at least one signal detector coupled to the outcoupling points to generate the output signal, the method operating in a sequence of repetitions, each repetition comprising the steps of:
processing the output signal to generate a set of data samples, each data sample being generated to represent detected energy for one of the actual detection lines; generating an interpolated sinogram based on the set of data samples, the interpolated sinogram comprising interpolation samples which represent fictitious detection lines that have a desired location on the surface portion; and operating an image reconstruction function on the interpolated sinogram to generate a signal interaction pattern within at least part of the surface portion; said method further comprising an error correction step which is responsive to exclusion data that identifies a change in validity status for a data sample among the set of data samples in a current repetition, said error correction step comprising: identifying interpolation samples affected by the change in validity status; and setting each identified interpolation sample to a value that maintains a relative signal transmission of the fictitious detection line from a former repetition.