Continuous-type inkjet printers (CIJPs) can be used to print on surfaces with various shapes at high speeds without contacting the printing target. Recently, the need for CIJPs with higher speeds and quality to speed up industrial production lines has been increasing. By increasing the exciting frequency of the piezo element, the ink droplet generation cycle can be shorter, thereby increasing the printing speed. However, as the distance between each charged ink droplet becomes shorter, forces such as air drag and Coulomb repulsion can greatly affect the trajectories of the droplets and may deteriorate the printing quality. To determine the optimal particle injection pattern, we developed an automatic design technique with a multi-objective genetic algorithm (MOGA) and ink droplet trajectory simulation and applied it to the character "7" in a 5 × 5 dot matrix. A MOGA with 20 populations and four generations was performed, and it was confirmed that the developed technique could automatically improve the printing quality of the character. Additionally, correlation analysis was applied to the data obtained from the optimization and some printing control rules to improve the quality were extracted. By applying the rules to the character "3" and "5," it was revealed that the printing qualities of those characters could be also improved.
Koma Sato, Eiji Ishii, Nobuhiro Harada, Tsuneaki Takagishi, "Study on printing quality improvement for continuous-type inkjet printer using multi-objective genetic algorithm and ink droplet trajectory simulation" in Proc. IS&T Printing for Fabrication: Int'l Conf. on Digital Printing Technologies (NIP33), 2017, pp 128 - 132, https://doi.org/10.2352/ISSN.2169-4451.2017.33.128