Statistical analyzing method and statistical quality indicator for reliability improvement of a capacitive touch device

摘要

For a capacitive touch device having a capacitive touch sensor to be sensed to generate sensed values, a sensing apparatus and method statistically analyze the sensed values generated in a certain time period to evaluate the sensing quality thereof, discard the poor reliable sensed values, and re-sense the capacitive touch sensor to generate new sensed values, by which the resultant output signal will have improved reliability.

主权项

1. A reliability improved sensing apparatus for a capacitive touch device having a capacitive touch sensor, said sensing apparatus comprising:
an excitation unit connected to said capacitive touch sensor and controlled to apply an excitation signal to said capacitive touch sensor; a sampling unit connected to said capacitive touch sensor and controlled to sample and convert sensing signals received from said capacitive touch sensor to generate sensed values; a control unit connected to said excitation unit and said sampling unit, operative to control said excitation unit and said sampling unit for timing control based on a sensing frequency; and a statistical quality indicator connected to said sampling unit and said control unit, performing statistical analysis to said sensed values in a statistic cycle for evaluating a sensing quality to determine to discard poorly reliable sensed values, wherein the statistical quality indicator determines whether each sensed value exceeds a defined reasonable range and counts a number of said sensed values outside the defined reasonable range in said statistic cycle, and triggers a redo signal for said control unit when said number is larger than a defined threshold.