Patent ID: 8371221
Filing Date: 2013-02-12
Classification: B41F

Abstract:
1. A method for controlling an application of ink in a printing press, the method comprising the following steps: predefining at least one setpoint color value in a device-independent color space; activating an ink metering element in the printing press with an ink application value to produce, on a printing material, an ink layer thickness associated with the setpoint color value; determining at least one actual color value of the ink layer thickness produced on the printing material in the device-independent color space; carrying out an activation with a changed ink application value as a function of a deviation of the actual color value from the setpoint color value, to produce an ink layer thickness differing from the ink layer thickness produced; determining the changed ink application value by calculating a necessary ink layer thickness change as a function of changes in the color values in the device-independent color space in the event of a change in the ink layer thickness at a point of the actual color value, the changes in the color values in the device-independent color space in the event of a change in the ink layer thickness being partial derivatives of the color values in the device-independent color space with respect to the ink layer thickness; and calculating the ink layer thickness change dF in accordance with a formula: where ΔS=(∂L/∂S, ∂a/∂S, ∂b/∂S, ∂I/∂S) at a point LabI ΔLabI=LabI i counts off vector components, and summation is carried out over i=1, 2, 3 and 4.