Printing apparatus and driving method therefor

A printing apparatus comprising:

• a printing unit including at least two nozzle arrays arranged in a first direction, each nozzle array including a plurality of nozzles arranged along a second direction intersecting the first direction;
• a conveying unit configured to convey, in the first direction, a sheet to be printed;
• a driving unit configured to drive the printing unit so as to print an image corresponding to print data on the sheet conveyed by the conveying unit and print, on the sheet, an adjusting pattern for acquiring a print position shift amount of a dot in the first direction between the nozzle arrays at a predetermined interval;
• a reading unit configured to read a printing result by the printing unit on the downstream side of a conveying direction of the sheet with respect to the printing unit;
• an acquisition unit configured to acquire the print position shift amount between the nozzle arrays based on a result of reading, by the reading unit, the adjusting pattern printed on the sheet while the conveying unit conveys the sheet;
• and
• a print data generation unit configured to generate the print data,
• wherein the print data generation unit performs
• a first operation of expanding print data onto a memory in correspondence with the first direction and the second direction,
• a second operation of, in each nozzle array for every column data corresponding to the second direction in the expanded print data, determining some of the plurality of nozzles as non-discharge nozzles so the nozzles do not overlap each other between the nozzle arrays in the first direction, and the remaining nozzles of the plurality of nozzles as discharge nozzles,
• a third operation of determining print data to be assigned to each nozzle array so that printing of dots corresponding to each column data is completed by printing dots corresponding to the determined non-discharge nozzles of a given nozzle array of the plurality nozzle arrays by the determined discharge nozzles of another nozzle array of the plurality of nozzle arrays,
• a fourth operation of inserting null data as column data corresponding to the print position shift amount acquired by the acquisition unit to the determined print data, and
• a fifth operation of distributing the print data to the respective nozzle arrays so as to newly determine discharge nozzles and non-discharge nozzles in response to insertion of the column data of the null data, and print, by the newly determined discharge nozzles, dots corresponding to the print data to which the column data has been inserted.