Disclosed is a method for inputting graphical information into a computer system. The graphical information may arise when a drawing device is moved relative to a base having a position-coding pattern detectable by an optical sensor in the drawing device. The computer system may record position information...http://www.google.com/patents/US20020008721?utm_source=gb-gplus-sharePatent US20020008721 - Method and system for digitizing freehand graphics with user-selected properties
