Patent ID: 7405839

Claim:
A printing apparatus which performs printing on a printing medium on the basis of print data transmitted from a host apparatus by using a printhead in which a plurality of printing elements are arrayed in a predetermined direction, comprising: scanning means for scanning the printhead in a main scanning direction crossing to the predetermined direction; a buffer which stores the print data transmitted from the host apparatus in order to transfer the print data to the printhead, and is smaller in capacity than a print data amount for printing by scanning the printhead by a width scannable by said scanning means; block management means for dividing said buffer into a plurality of blocks corresponding to rectangular regions printed by scanning, managing a use order of the blocks so as to circularly store print data in the blocks along with progress of printing, and further managing print data input to said buffer and print data output from said buffer such that print data to be printed during a single scanning is stored in each block of said buffer and the print data stored in each block of said buffer is transmitted to the printhead; and null data management means for, when print data representing non-driving of the printing elements successively exist in a predetermined amount, representing the predetermined amount of print data by specific control data without storing the predetermined amount of print data in the blocks.