Touch surface with identification of reduced performance

Abstract

A device is configured to process data from a touch-sensitive apparatus for the purpose of identifying a reduced performance of components in the apparatus. The apparatus may be an FTIR system that comprises a light transmissive panel, an illumination arrangement for introducing light into the panel, and a light detection arrangement for receiving the light propagating in the panel and for measuring the energy of the received light. The device comprises a processor unit which is configured to obtain a signal comprising a time series of signal values that represent the energy of the light received by the light detection arrangement; calculate a parameter value representing a temporal variability of the signal values in the signal; and identify, based on the parameter value, a reduced performance of any of the illumination arrangement and the light detection arrangement. The temporal variability may be calculated to represent one of an absolute noise level and a signal-to-noise ratio of the signal, and enables the reduced performance to be identified while objects touch the light transmissive panel.

Dependencies are inferred from the claim text.