Patent ID: 7679767

Claim:
A printing system comprising: a first printer; a second printer connected to the first printer, the first and second printers executing printing based on print data; and a print instruction unit connected to the first printer, wherein the first printer and the print instruction unit are connected so that data can be transmitted, and the first printer and the second printer are connected so that data can be transmitted; the print instruction unit includes: a print-instruction-information generating unit that generates first print-instruction information containing the print data and first authentication information; a print-instruction-information transmission unit that transmits the first print-instruction information generated by the print-instruction-information generating unit to the first printer; a print-instruction-information acquisition unit that obtains second print-instruction information of the print data for the second printer, the second print-instruction information containing second authentication information corresponding to the first authentication information; and a print-request-information transmission unit that transmits print-request information to the first printer, the print-request information containing information on the second printer in addition to the second print-instruction information obtained by the print-instruction-information acquisition unit; the first printer includes: a print-instruction-information storage unit that stores the first print-instruction information received from the print instruction unit; a determination unit that receives the print-request information transmitted from the print-request-information transmission unit, and determines whether there is first print-instruction information corresponding to the print-request information based on the second authentication information in the received print-request information and the first authentication information contained in the first print-instruction information stored in the print-instruction-information storage unit; and a print-data transmission unit that transmits print data corresponding to the print-request information to the second printer corresponding to the print-request information when it is determined from the determination result of the determination unit that first print-instruction information corresponding to the print-request information is present; and the second printer executes printing based on the print data received from the first printer and corresponding to the print-request information.