Inkjet printing apparatus and method for controlling drive of nozzles in inkjet printing apparatus

A method for controlling drive of nozzles in an inkjet printing apparatus that prints dot for forming an image on a print medium by scanning, relatively to the print medium, a printhead having a plurality of nozzles forming a nozzle array in a direction intersecting with the nozzle array, such that each raster for forming the image is printed by different nozzles in each of multiple scans, the method comprising the steps of:

• a drive control step of dividing the plurality of nozzles into groups, each including a plurality of adjacent nozzles and controlling drive of nozzles such that drive timings of nozzles differ among a plurality of blocks in each group, where one block corresponds to one nozzle from each group;
• and
• a determination step of determining, for each of the multiple scans, a sequence in which nozzles are driven by the drive control step,
• wherein the adjacent printed dots are printed by two nozzles and the drive timings of the two nozzles are different from each other,
• wherein the determination step determines, for each scan, a sequence in which nozzles among the plurality of blocks are driven, such that each interval distance between the adjacent printed dots is substantially equal in the raster,
• wherein the each interval distance corresponds to a timing difference of drive timings for printing the adjacent printed dots, and
• wherein the timing difference corresponds to a number of blocks plus a quotient value of the number of blocks divided by a number of scans.

An inkjet printing apparatus that prints each raster on a print medium by moving, relatively to the print medium, a printhead having a plurality of nozzles forming a nozzle array in a direction intersecting with the nozzle array, such that the multiple scans are executed by different nozzles for respectively printing the each raster in multiple scans, the apparatus comprising:

• a drive control unit configured to divide the plurality of nozzles into groups, each including a plurality of adjacent nozzles and control drive of nozzles such that drive timings of nozzles differ among a plurality of blocks in each group, where one block corresponds to one nozzle from each group;
• and
• a determination unit configured to determine, for each scan, a sequence in which nozzles are driven by the drive control unit,
• wherein the determination unit determines, for each of the multiple scans, a sequence in which nozzles among a plurality of blocks are driven, such that each interval distance between adjacent printed dots is substantially equal in the raster,
• wherein the adjacent printed dots are printed by two nozzles, the drive timings of which are different from each other, and
• wherein the determination unit determines, for each of the multiple scans, the sequence in which nozzles among a plurality of blocks are driven so that the each interval distance is longest of all possible sequences for which the each interval distance is substantially equal.