Mixer for use in touch panel system and method for processing signals in the mixer

Abstract

A mixer of a touch panel system includes a first switch configured to switch a sensing signal in accordance with a reference signal; a second switch configured to switch the sensing signal in accordance with a phase-inverted reference signal from the reference signal. Further, the mixer of the touch panel system includes a first low pass filter configured to perform low-pass filtering on a first output signal produced from the first switch; and a second low pass filter configured to perform low-pass filtering on a second output signal produced from the second switch. Furthermore, the mixer of the touch panel system includes a differentiator configured to differentiate signals produced from the first low pass filter and the second low pass filter, to thereby produce a signal of constant level as the sensing signal.

Dependencies are inferred from the claim text.