Ink-jet printer and printing head driving method therefor
AssigneeCanon Kabushiki Kaisha
InventorTakashi Inoue
Life of this patent
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Abstract
An ink-jet printer for printing by scanning a printing head having a plurality of nozzles arranged in a predetermined direction, each designed to discharge an ink droplet (100), over a printing medium in a direction substantially perpendicular to the array direction of the nozzles includes a driving means for time-divisionally driving the nozzles in accordance with driving signals (300) with timings of a plurality of blocks. When multipass printing is performed by scanning different nozzles over each printing area a plurality of times, the driving means drives nozzles used to print the same raster at timings of at least two different blocks. This makes it possible to reduce density unevenness of a printed image due to periodic ink pressure variations.
Claims8
An ink-jet printing apparatus for printing by scanning a printing head having a plurality of nozzles arranged in a predetermined direction, composed of a plurality of nozzle groups each including continuously arranged plural nozzles in the predetermined direction, each nozzle for discharging an ink droplet, over a printing medium in a direction substantially perpendicular to an arranged direction of said nozzles, comprising:
- driving means for time-divisionally driving said nozzles according to block drive timing signals of a plurality of time-divisionally driven blocks of said plurality of nozzles,
- wherein said driving means includes a circuit for determining a relationship between nozzle positions in each of said nozzle groups and a driving sequence of said nozzles in each of said nozzle groups, such that a driving sequence of said nozzles in one of said nozzle groups is different from a driving sequence of said nozzles in another of said nozzle groups, and
- wherein when multipass printing is performed by scanning different nozzles over each printing area a plurality of times, said driving means drives nozzles used to print the same raster according to block drive timing signals of at least two different blocks.
Dependencies are inferred from the claim text.