Measuring circuit for touch sensor of e.g. laptop computer, determines occurrence of touch input on sensor, based on charge voltage level obtained by the modification of voltage across integration capacitor from reference voltage level

摘要

The circuit applies first current to a capacitor of touch sensor (10) for altering the first time period in which voltage on capacitor is converted from reference voltage level to first predetermined voltage level. A second current applied to integrating capacitor, is proportional to first current. The voltage across integration capacitor is modified from reference voltage level to first charging voltage level, on application of second current to integrating capacitor for the first time. The occurrence of touch input is determined based on first charging voltage level. Independent claims are included for the following: (1) computer-readable non-transitory storage medium storing program for measuring change in capacitance across field, for detecting presence and location of touch or approach of object within touch-sensitive area of touch sensor; and (2) touch sensor.