Abstract: A printing method for three-dimensional painting by UV digital printing device has acts of: First, preparing a printing device having a white print set and a color print set. Second, moving the printing device transversely from one side to the other side of an object for multiple times, wherein the two print sets respectively print on two adjacent zones. Third, moving the printing device longitudinally to next zone on the object. Fourth, repeating the second and third acts until the printing device moves over a last zone on the object. The printing device moves longitudinally after the printing device moves transversely to and fro to finish the height of a zone. Thus, the printing device completes all the heights and the colors in one time of longitudinal moving. Then printing consumes less time and the printing device therefore does not have to be orientated again.

Abstract: A pneumatic ink-jet system is applied in an inkjet printer and uses a negative pressure generator, which is designed according to the Bernoulli's Theory, with a stable airflow in a certain speed to generated stable pressure inside at least one inkpot and at least one print head. Therefore, the at least one print head is kept in an appropriate wet state and the quality of printing is enhanced. Moreover, a top surface of the ink inside the at least one inkpot can be controlled to be higher than the at least one print head, so the pneumatic ink-jet system can be applied in a large format inkjet printer.

Abstract: A pneumatic ink-jet system is applied in an inkjet printer and uses a negative pressure generator, which is designed according to the Bernoulli's Theory, with a stable airflow in a certain speed to generated stable pressure inside at least one inkpot and at least one print head. Therefore, the at least one print head is kept in an appropriate wet state and the quality of printing is enhanced. Moreover, a top surface of the ink inside the at least one inkpot can be controlled to be higher than the at least one print head, so the pneumatic ink-jet system can be applied in a large format inkjet printer.