Electronic device, has detector unit detecting whether contact at or near location of touch sensor is occurred, based on response of location of touch sensor to measurement signal, where touch sensor detects periodic noise signal

摘要

The device has a touch sensor (10) for detecting a periodic noise signal e.g. network hum signal, caused by an external power source (24) that is removably coupled with the touch sensor. A signal generator generates a measurement signal, which is synchronized with the periodic noise signal. A detector unit detects whether a contact at or near the location of the touch sensor is occurred based on response of a location of the touch sensor to the measurement signal. A comparator is connected with the periodical noise signal and a programmable voltage source.