To carry out correct overprinting even when the mounting position of a print head and the accuracy of a head clearance are relaxed.

Correct overprinting is made to an absolute position within a device without containing the time component in the main scanning direction in each timing of starting printing by counting encoder signals from an encoder 600 having a resolution of one Nth the printing resolution, outputting independently timing signals 1301 to 1304 each showing a printing start position in the main scanning direction for print heads 501 to 504, respectively, and controlling the timing of starting printing for the print heads 501 to 504, respectively independently.