JPH05334470

PURPOSE: To provide a self-clocking graphic mark code for easily encoding a multi bit digital value graphically at the time of encoding digital information enabling mechanic reading on a hard copy recording medium. CONSTITUTION: This system is provided with a series of logically sequenced graphic marks 31a-31d to be written in a recording medium according to a preliminarily decided spatial formatting rule. Each graphic mark 31a-31d is provided with plural preliminarily decided identifiable graphical characteristics 32 and 33, and each graphical characteristic 32 and 33 is provided with plural preliminarily decided identifiable graphical states 32 and 33. This system is provided with a multi bit digital value respectively encoded in a preliminarily decided logical sequence in the states of the graphical characteristics 32 and 33 of each graphic mark 31a-32d, and each digital value is encoded as plural logically sequenced bit strings.