US Patent 7982885 Electronic pen with retraction mechanism and force sensor

An electronic pen for interacting with a substrate having coded data disposed thereon. The pen comprises: an image sensor for sensing the coded data when the pen is used to interact with the surface; a cartridge having a nib for contacting the surface; a retraction mechanism for slidably moving the cartridge between a retracted position and an extended position; a force sensor cooperating with the retraction mechanism; a processor configured to generate indicating data indicative of the interaction with the substrate; and communication means for communicating the indicating data to a computer system. The image sensor is configured to sense the coded data only when the force sensor detects that the nib is in contact with the substrate.