摘要 |
In an ink-jet head including black, yellow, magenta, cyan nozzle rows, the nozzle rows are arranged so that in each of the nozzle rows, adjacent nozzles are arranged by a predetermined spacing distance P, and that the black nozzle row is shifted in a nozzle-row alignment direction by a spacing distance smaller than the predetermined spacing distance P, with respect to the cyan, magenta and yellow nozzle rows. When a black dot is formed between monochrome-black dots adjacent in the sub-scanning direction, a dot of color-mixed black which is a mixture of the other three colors is formed between the monochrome-black dots. At this time, by adjusting a black-ink jetting amount to be greater than a total amount of the other three color inks, it is possible to make the monochrome-black dot and the color-mixed black dot to be mutually uniform in size.
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