| 摘要 |
PROBLEM TO BE SOLVED: To enhance print quality, including increase of density, while allowing shift even if ink dots are superposed while being shifted by causing a black ink to react on a color ink having different polarity at a density lower than that of a color ink having higher brightness thereby forming a black image. SOLUTION: At the time of printing a character with black (BK) ink, cyan (light cyan) ink of low color density is superposed entirely or partially on an image of black ink. If anion based BK ink is employed, cation based light cyan ink having different polarity is employed so that both inks are mixed on a print medium to render the coloring matter insoluble or to cause aggregation. Consequently, even if superposition of ink dots deviates from a specified range, it cna not be recognized visually and the density of black image can be increased by adding the coloring matter of C to a BK pixel. |
