PRINTER

摘要

PURPOSE: To obtain constant density regardless of the change of the kind of a medium or the secular change of the medium. CONSTITUTION: A gradation data control part 20a issues a command so as to print a test printing pattern and a density sensor 11 reads the density of the test printing pattern actually printed on a medium. The gradation data control part 20a divides the density from the set min. density to max. density among the densities on the medium read by the density sensor 11 by the necessary number of gradations to obtain sampling gradation data and corrects the gradation data inputted to a printer on the basis of the corresponding relation between the sampling gradation data and the gradation of the test printing pattern.