Self-contained pen-like devices have been described which mark a surface while simultaneously capturing their own movement relative to the surface. Some such devices sense their own movement using embedded accelerometers. Others sense their own movement by detecting information which is machine-readably encoded on the surface. In this latter category, see for example U.S. Pat. No. 5,477,012, U.S. Pat. No. 5,652,412 and PCT application WO99/50787.
Since these pen-like devices typically include an integral marking means, they support only a limited set of marking modes or styles.
USPTO Backgrounds
USPTO Backgrounds