Inverted driving technique for removing display noise in capacitive touch sensors

Abstract

As the technological advances in mobile display is focusing on thinner and wider structures, capacitive touch recognition suffers from ever-increasing display noise. Realizing reliable touch recognition in thin displays requires a way to remove display noise. We observed that display noise is evident in various patterns and amplitudes according to the display image. In order to remove noise, we applied non-inverse signals and inverse signals across two data frames, in accordance with the periodicity of the noise. With all other conditions remaining the same, the proposed method showed higher signal-to-noise ratio (SNR) for all display noise patterns compared to existing methods. The proposed method showed a SNR that was averagely 5.39 dB higher than the SNR of the existing method. The results shows that the display noise was removed effectively.