| 摘要 |
PURPOSE:To eliminate the difference in density between a single color black picture element and a black picture element in color reduced mixing, in the color printer, wherein printing is performed by using a plural kinds of inks including a black ink, by increasing the projecting amount of the black ink larger than the projecting amounts of the inks of other colors. CONSTITUTION:In the color ink jet printer, e.g. ink jet heads H1-H4 are provided for black K, cyan C, Magenta M, and yellow Y. In this case, the nozzle diameter of the black ink jet head is made larger than the nozzle diameters of the ink jet heads of the other colors. Thus the projecting amount of the black ink is increased. In this way, the density of the picture element of the black color K becomes the equal density of the black picture element in the case the three colors are mixed. In order to increase the projecting amount of te the black ink, a voltage V1, which is applied to a transistor Q1 for the head H1 of the black color K, can be made higher than a voltage V2, which is applied to transistors Q2-Q4 for the other heads H2-H4. |
