Patent ID: 7528994

Claim:
A printing data preparation apparatus comprising: a plurality of printing ports, each printing port including: a printer driver unit that converts printing data into printer interpretable data to be output to a printer, a ground-tint data storage unit that stores unique ground-tint data, the ground-tint data includes a copy-suppression pattern that is prepared by combining an optically readable copy-surviving pattern with an optically difficult-to-read copy-extinctive pattern and are manifested in reproductions, and a ground-tint adding unit that adds the ground-tint data stored in the ground-tint data storage unit to the printer interpretable data output from the printer driver unit; a printing port selecting unit that changes a printing port to input the printing data with time; and a specific number calculating unit that calculates a specific number using date and a predetermined function, wherein the printing port selecting unit changes the printing ports based on the number calculated by the specific number calculating unit.