What can we feel on the back of the tablet? — A thin mechanism to display two dimensional motion on the back and its characteristics

The front surface of the tablet style smartphone or computer is dominated by a touch screen. As a finger operation on the touch screen disturbs its visibility, it is assumed a finger touches the screen instantly. Under such restriction, use of the rear surface of the tablet for tactile display is promising as the fingers holding the tablet constantly touch it and feel the feedback steadily. In this paper, a slim design of tactile feedback mechanism that can be easily installed on the back of existing tablets is given and its mechanical performance regarding electricity consumption, latency and force is evaluated. Human capability in perceiving the tactile information on the display is also evaluated.