公开(公告)号：US20170217163A1

公开(公告)日：2017-08-03

申请号：US15391985

申请日：2016-12-28

Applicant: HEIDELBERGER DRUCKMASCHINEN AG

Inventor： ILIAS TRACHANAS ,  GERD JUNGHANS

IPC: B41J2/045 ,  H04N1/405 ,  G06K15/02 ,  B41J29/393

Abstract: A method for modifying color density values in a dot-based printing system uses a control unit. The control unit implements the modification of the color density values after a raster image has been created and modifies the number and/or size of print dots to be applied to a printing substrate in order to attain pre-defined color density target values.

公开(公告)号：US20180257390A1

公开(公告)日：2018-09-13

申请号：US15897391

申请日：2018-02-15

Applicant: HEIDELBERGER DRUCKMASCHINEN AG

Inventor： MARTIN MAYER ,  ILIAS TRACHANAS ,  ANDREAS SCHOEMANN ,  GERD JUNGHANS ,  THOMAS SCHRANK

IPC: B41J2/21

CPC classification number: B41J2/2132 ,  B41J2/211 ,  B41J2/2121 ,  G01J3/46 ,  H04N1/4057 ,  H04N1/502

Abstract: A method corrects color density unevenness during a printing operation on an inkjet printing machine having printing nozzles and a computer. The computer modifies the number or size of the drops to be applied to a printing substrate to attain nominal color density values after the processing of a rasterized print image. For different actual tone values, it is determined which target tone value is required to attain a nominal coloration by measuring a test image for every printing nozzle using a color measurement device, and, based thereon, an area coverage-dependent compensation profile is determined and saved on the computer to be applied in the printing operation to calculate the number and size of the drops on the computer.