Patent ID: 8720338
Filing Date: 2014-05-13
Classification: B41F

Abstract:
1. A method for controlling the ink quantity applied to a material being printed by a printing unit, the printing unit including an inking roller and a corresponding printing roller, comprising the steps of: a) driving the inking roller in rotation at a first inking speed (VIR1), and simultaneously driving the printing roller in rotation at a first printing speed (V1); b) changing the rotation speed of the printing roller to a second printing speed (V2); c) changing the rotation speed of the inking roller to a second inking speed (VIR2) during or after the change in the rotation speed of the printing roller based on a speed correction index (TI d) measuring at least a first ink quantity (D(V1)) applied to the material being printed when the inking roller and the printing roller rotate at the first inking speed (VIR1) and printing speed (V1); e) measuring at least a second ink quantity (D(V2)) applied to the material being printed when the inking roller and the printing roller rotate at the second inking speed (VIR2) and second printing speed (V2); f) calculating a value for the difference (S) representing the difference in the ink quantity applied between the first and second ink quantities printed; g) generating a new speed correction index TI h) maintaining a desired ink quantity by using the new speed correction index TI i) driving the inking roller in rotation at the first inking speed (VIR1), and simultaneously driving the printing roller in rotation at the first printing speed (V1); j) changing the rotation speed of the printing roller to the second printing speed (V2); and k) changing the rotation speed of the inking roller to the second inking speed (VIR2) during or after the change in the rotation speed of the printing roller in step j) based on the new speed correction index TI