Ink jet printing apparatus and ink jet printing method with varied relative bias of printing permission ratio between print modes

摘要

A printing apparatus that includes nozzle arrays, formed of nozzles for ejecting ink of the first to fourth ink color groups, and that scans a print medium while moving the nozzle arrays to perform printing. For printing a unit area of a print medium, where printing is to be completed by performing a plurality of scans, the printing apparatus performs a plurality of scans, and conveys, between movements, a print medium a predetermined amount, which is equivalent to the width of the unit area. Then, to perform a plurality of scans using the nozzle arrays for the first to fourth ink color groups, print data are generated, so that for the nozzle arrays that belong to two ink color groups, the nozzle array for the first ink color group is employed to eject ink into the unit area prior to the nozzle array for the second ink color group.

主权项

1. An ink jet printing apparatus that performs a plurality of scans of a print head provided with a plurality of nozzle arrays for respective ink colors, where each of the plurality of nozzle arrays is formed from a plurality of nozzles for ejecting ink which are arranged in a predetermined direction, the plurality of nozzle arrays being arranged in an intersecting direction that intersects the predetermined direction, with a print medium being conveyed in the predetermined direction between the plurality of scans, to perform printing to a unit area of the print medium, which is a unit area where printing is completed by the plurality of scans in a scan direction that intersects the predetermined direction, said apparatus comprising:
a control unit configured to selectively perform a first print mode, in which the scan by the print head to the print medium is performed M times, conveying of the print medium at a first conveyance amount between the M times of scans being performed, to complete the printing to the unit area, a second print mode, in which the scan by the print head is performed N times, N being greater than M and the conveying of the print medium at a second conveyance amount between the N times of scans being performed, to complete the printing of the unit area, and a third print mode which completes printing to the unit area by L times of scans, L being greater than M but less than N; and a printing ratio determination unit configured to determine a printing permission ratio for each of the nozzles of the print head for each of the plurality of scans, so that the printing permission ratio is determined independently for the ink colors and with having a relative bias for each ink color with respect to a nozzle array according to the performed printing mode, wherein said printing permission ratio determination unit determines the printing permission ratio for the printing head so that the relative bias of the printing permission ratio for each ink color with respect to a nozzle array is increased in an order of the first print mode, the third print mode and the second print mode, and wherein said printing permission ratio determination unit determines the printing permission ratio for the printing head so that in the case of performing printing of the second and third print modes, a center of gravity of the printing permission ratio with respect to the nozzle array which ejects a higher print density ink is located at an upper stream in the predetermined direction.