Sonar Drawing Tablet

Posted by Ben-Goldberg@reddit | CrazyIdeas | View on Reddit | 5 comments

This drawing tablet looks like a clipboard, and is a clipboard, but it also has microphones on the corners and edges.

These mics listen to the sound of you drawing, and locate where your pencil is drawing using the difference in timing and volume of the sounds arriving at the mics.

It would probably also work if you drag a retracted pen or fingernail across the surface.