Performance monitoring and correction in a touch-sensitive apparatus

A device for enabling touch determination based on an output signal from a touch-sensitive apparatus, the touch-sensitive apparatus including a panel, a plurality of peripheral light emitters, and a plurality of peripheral light detectors, the plurality of peripheral light emitters configured to transmit light signals to the plurality of peripheral light detectors, the transmitted light signals defining actual detection lines that extend across a surface portion of the panel between pairs of light emitters and light detectors, the touch sensitive apparatus further including at least one signal generator coupled to the plurality of peripheral light emitters to generate the light signals, and the plurality of peripheral light detectors configured to generate the output signal, wherein the device is configured to execute a sequence of repetitions, and the device comprises:

• means for processing, in each repetition, the output signal to generate a set of data samples, each data sample representing detected energy for one of the actual detection lines;
• means for generating a set of relative values from the data samples;
• means for generating, in each repetition, an interpolated sinogram based on the set of relative values, the interpolated sinogram including interpolation samples representing fictitious detection lines having a desired location on the surface portion of the panel;
• means for operating, in each repetition, an image reconstruction function on the interpolated sinogram to generate a signal interaction pattern within at least part of the surface portion of the panel and processing the signal interaction pattern to identify touch interaction;
• means for performing error correction in response to exclusion data identifying a change in validity status for a data sample, from among the set of data samples, in a current repetition;
• wherein said means for performing error correction includes
• means for identifying a relative value corresponding to the data sample affected by the change in validity status, and
• means for setting the identified relative value to a value that maintains a relative signal transmission of the fictitious detection line from a former repetition.

A device for enabling touch determination based on an output signal from a touch-sensitive apparatus, the touch-sensitive apparatus including a panel, a plurality of peripheral light emitters, and a plurality of peripheral light detectors, the plurality of peripheral light emitters configured to transmit light signals to the plurality of peripheral light detectors, the transmitted light signals defining actual detection lines that extend across a surface portion of the panel between pairs of light emitters and light detectors, the touch sensitive apparatus further including at least one signal generator coupled to the plurality of peripheral light emitters to generate the light signals, and the plurality of peripheral light detectors configured to generate the output signal, the device comprising:

• one or more processors configured to execute computer readable instructions to
• process the output signal to generate a set of data samples, each data sample representing detected energy for one of the actual detection lines;
• generate a set of relative values from the data samples;
• generate an interpolated sinogram based on the set of relative values, the interpolated sinogram including interpolation samples representing fictitious detection lines having a location on the surface portion of the panel;
• operate an image reconstruction function on the interpolated sinogram to generate a signal interaction pattern within at least part of the surface portion of the panel and processing the signal interaction pattern to identify touch interaction;
• and
• perform error correction in response to exclusion data identifying a change in validity status for a data sample, from among the set of data samples, in a current repetition among a sequence of repetitions;
• wherein said error correction includes
• identifying a relative value corresponding to the data sample affected by the change in validity status, and
• setting the identified relative value to a value that maintains a relative signal transmission of the fictitious detection line from a former repetition among the sequence of repetitions.