As anyone who has tried to use a touchscreen cellphone one-handed knows, there’s a point where that luxuriously large display ends up a chore when your thumb can’t stretch over far enough.  Smaller handsets don’t have the same problem, but then you miss out on the big screen.  Mitsumi believe they’ve solved the problem with their latest haptic input device, however; on the front is the usual display, but on the back is a coin-sized control panel covered in textured nubs which your forefinger strokes against to make menu selections.

The panel is in fact a resistance-sensitive touchpad, with each raised bump a trigger button for the corresponding menu option on the other side.  According to Mitsumi, such a design makes input on any size of screen straightforward with just one hand.

No specific commercial application for the design was discussed, nor whether Mitsumi would apply the technology themselves or licence it out.