Enabling tangible interaction on capacitive touch panels

Abstract

We propose two approaches to sense tangible objects on capacitive touch screens, which are used in off-the-shelf multi-touch devices such as Apple iPad, iPhone, and 3M's multi-touch displays. We seek for the approaches that do not require modifications to the panels: spatial tag and frequency tag. Spatial tag is similar to fiducial tag used by tangible tabletop surface interaction, and uses multi-point, geometric patterns to encode object IDs. Frequency tag simulates high-frequency touches in the time domain to encode object IDs, using modulation circuits embedded inside tangible objects to simulate high-speed touches in varying frequency. We will show several demo applications. The first combines simultaneous tangible + touch input system. This explores how tangible inputs (e.g., pen, easer, etc.) and some simple gestures work together on capacitive touch panels.