Visio-Acoustic screen for contactless touch interface with tactile sensation

This paper proposes a contactless touch screen that produces tactile sensation just 1-3cm before the actual touch on the screen. The system has a screen, visual projectors, and sensors for finger motion detection, which composes a non-contact touch screen by gesture sensing. In this paper we add a non-contact tactile display using an airborne ultrasound phased array. The key device of the system is a screen that is a scattering plane for visual projectors and transparent for ultrasound. We show the design of the screen and examine the effectiveness through numerical simulations and experiments. The screen has an additional property that stops the air flow going through the screen maintaining the transparency for the ultrasound. We constructed the contactless touch screen system and examined the position sensing accuracy under the tactile support.