Method for optical reflection measurements and a densitometer and printing control strips for carrying it out

摘要

The method is specific to optical reflection measurement on printing control strips on multicolour printed sheets, using a densitometer, with whose measuring unit specific measuring fields of the printing control strip are measured and the measured values are converted so as to be evaluable in the computer of the densitometer. In order to carry out the measuring process simply and quickly and to be able to design the device for carrying it out relatively simply, specifically not only with respect to its constructional expense, but also with respect to its programmability, the process according to the invention is carried out in such a way that a printing control strip having measuring fields arranged corresponding in size and according to colour and type (full-tone, middle-tone, under-tone), and that, for carrying out the measurement, a plurality of sensors is simultaneously brought into position on correspondingly spaced measuring fields of the printing control strip and, in so doing, the full-tone, middle-tone and under-tone densities of the printing inks involved in the image make-up and correspondingly present in the printing control strip are measured with a maximum of two measuring processes.