Verfahren und Gerät zum Drucken

摘要

In the case of printing in three-value level utilizing two kinds of inks mutually different densities for one color (higher and lower density inks), it is assumed that a reflection density of a region having a predetermined area (C, D) when solid print is performed only by the lower density ink, and when solid print is performed only by the higher density ink are expressed ODt and ODn, respectively. Since the granular appearance of the ink dots is expressed in terms of reflection density of one dot, the granular appearance of a lower density ink dot at a portion (A) of image formed only by the lower density ink dots and the granular appearance of a higher density ink dot at a portion (B) of image formed by the higher and lower density ink dots are expressed in terms of values of ODt and (ODn - ODt) divided by the number of pixels included the above region, respectively. Accordingly, by making the reflection density ODt to be approximately one half of the reflection density ODn, the granular appearance produced by the lower density ink dot at the highlighted portion and the granular appearance produced by the higher density ink dot at the portion where the higher density ink dots scattered in the lower density ink dots can be made substantially equal to each other. For this purpose, it is preferable that a dye concentration of the lower density ink is to be about one fourth of that of the higher density ink.