In-air Typing Interface: Realizing 3D operation for mobile devices

In this paper, we explore the usability of the “In-air Typing Interface” that we developed to overcome the problems common with traditional mobile interfaces. We performed two studies focused on frame rate, latency, and tactile feedback. We found that reducing the latency even by several milliseconds can improve the operating efficiency, and the frame rate partly affects the efficiency. Tactile feedback significantly reduced the number of mistypes, and it is likely that vibration feedback can improve the operating efficiency further if there is a penalty for erroneous operations.