High rate, low-latency multi-touch sensing with simultaneous orthogonal multiplexing

Abstract

We present "Fast Multi-Touch" (FMT), an extremely high frame rate and low-latency multi-touch sensor based on a novel projected capacitive architecture that employs simultaneous orthogonal signals. The sensor has a frame rate of 4000 Hz and a touch-to-data output latency of only 40 microseconds, providing unprecedented responsiveness. FMT is demonstrated with a high-speed DLP projector yielding a touch-to-light latency of 110 microseconds.