Téléchargement du mémoire : partie A - Ecole nationale supérieure ...

Abstract.The purpose of this study is to evaluate the capacity of an ink-jet system jet by "drop ondemand" to simulate the screen of an Offset press for proofing, in terms of details and valuesrendering.The knowledge of the various elements which oppose an ink-jet system and an Offsetpress is essential. Initially, we will define the printing principle of the two processes. If thetraditional screen is usually used in offset, it is that the printing technology makes it possiblewith difficulty to employ a stochastic screening as for the ink jet process. The concept ofscreen is fundamental since the ink-jet proofing consists in simulating a traditional screenusing a stochastic system of screening.Being given the difference in technology between the two processes, offset and ink-jetinks and papers are not the same ones. A study of their composition and their properties willallow a better comprehension of the interaction between inks and support for the two printingsystems. The structure of the support and inks influences the quality of details rendering,which depends on the penetration of ink in the support, like on values rendering, dependenton the optical properties of paper.The system of ink-jet printing includes the printer and a RIP. We will need to know thelimit of resolution of the printer as well as the influence on details rendering of the treatmentof the files by the RIP. That will enable us to determine the constraints of printing accordingto the traditional screen to simulate.The result of these various stages is the evaluation of a test carried out under the bestpossible conditions by comparison with the pullings of reference printed on a press offset.3