Simultaneous geometry and texture display based on lateral force for touchscreen

Displaying haptic and tactile information on a touchscreen is one of the key technologies for human interfaces. In this paper we propose a method that allows the user to simultaneously feel both large bump and small textures through a screen. Our method employs lateral force and direction-controlled mechanical vibration (around 0-400 Hz). The technology allows not only geometrical shapes but also textures to be felt. Our experiments revealed that with our proposed method almost all people can simultaneously detect geometry and texture information on a touchscreen. In addition, providing adequate direction for the vibration enhances the feelings of softness.