Touchable Wall: Easy-to-Install Touch-Operated Large-Screen Projection System

Recently, small and inexpensive portable projectors are commonly being used for presentations. For convenience, it is desired to perform a direct pointing operation on the screen without requiring to grip or mount any device and control the pointer intuitively. Therefore, this study proposes a new touch-operated large-screen projection system using acoustic vibration sensing and a projector-camera system. We apply a continuous signal in the inaudible range of an actuator to a surface and acquire its elastic compliance change as a resonance of sounds. We perform touch detection, position estimation, and pressure estimation by using machine learning techniques. Our actuator and sensor units are small and easy to install on a surface. Furthermore, our system can detect "true" touch without requiring any devices such as pens or pointers. We demonstrate a series of novel interactions for a large-screen projection system with our proposed technology through three applications.