Time or location seal creating device for document

摘要

The device has a writer unit (53) which interacts with the document (50). There is also a time of day/location definition unit which controls the writer unit. The time of day/location definition unit is a GPS unit (62), which is preferably a differential GPS unit using correction data from a reference base station, and which generates an additional satellite signal in addition to its normal output signals. The writer unit also receives the additional satellite information signals and writes these onto the document.