An accurate and efficient sampling algorithm for capacitive touch panels

Capacitive touch technology is used in almost all electronic devices with a user interface these days. Improved resolution and better responsiveness is always sought after in industry. The standard sampling method for electrodes on a capacitive touch panel comprises of measuring charge at every single electrode one by one which causes latency if the screen size is big. Compressive sensing has recently been proposed as an alternative sampling technique for capacitive touch panels [1]. However the proposed methods do not take into account the characteristics of capacitive touch signals. By utilising the unique block sparse nature of capacitive touch signals, an accurate and efficient greedy algorithm based on the existing block sparse greedy algorithms is proposed for recovering position of finger on a capacitive touch panel. High accuracy and efficiency are demonstrated through numerical simulations and compared with other notable block-based algorithms.