Carbon copy metaphor: Mode switching technique for trackpad-based manipulations

Drawing characters or images using smartphones and tablets is much easier than drawing using trackpads commonly equipped in laptops and desktop computers. The reason is that tablets are absolute coordinate input devices, whereas trackpads are relative coordinates input devices similar to conventional mouse. However, most of the modern laptops have trackpads approximately the same size as a smartphone screen, and they have enough space for hand-writing. We believe that modern trackpads would allow users to write easily as smartphones or tablets, if they properly provide an absolute coordinates input mode. This paper proposes a novel input technique that aims to switch between relative and absolute coordinates input methods seamlessly based on the "carbon copy" metaphor. We display a small workspace ("carbon copy area") on a computer screen that corresponds one-to-one with the handy trackpad. The user can input hand-written characters or images using absolute coordinates input on this virtual carbon copy paper and move it anywhere using relative coordinates. Our technique allows a user to call both absolute and relative coordinates input methods and use them appropriately with arbitrary timing. We developed a prototype application software to utilize this technique based on a preliminary experiment.