公开(公告)号：US20180288277A1

公开(公告)日：2018-10-04

申请号：US15938033

申请日：2018-03-28

申请人： HEIDELBERGER DRUCKMASCHINEN AG

发明人： DIRK KIRCHHOFF ,  BERND STRITZEL ,  MICHAEL KAISER

IPC分类号： H04N1/405 ,  B41J2/21 ,  H04N1/52

CPC分类号： H04N1/4057 ,  B41J2/2132 ,  B41J2/2146 ,  B41J2025/008 ,  H04N1/407 ,  H04N1/52

摘要： A method for compensating tone value fluctuation in inkjet printing includes generating multi-bit halftone images of pixels on a computer during prepress screening for color separations with multiple tone values out of print image data, forwarding multi-bit halftone images to a control unit of an inkjet printing machine, and printing the multi-bit halftone on the machine, wherein encoded binary values of multi-bit halftone images correspond to ink drop sizes to be generated by the machine. The computer introduces additional binary values of multi-bit halftone images not corresponding to ink drop sizes in pixel positions of multi-bit halftone images where occurring tone value fluctuations are to be compensated for by modified ink drop sizes, causing additional binary values to be ignored by the machine in a regular print mode, and assigning additional binary values to modified ink drop sizes in a correction print mode.

公开(公告)号：US20180264839A1

公开(公告)日：2018-09-20

申请号：US15902339

申请日：2018-02-22

申请人： HEIDELBERGER DRUCKMASCHINEN AG

发明人： BERND STRITZEL

IPC分类号： B41J2/21 ,  B41J2/205 ,  B41J2/155

CPC分类号： B41J2/2139 ,  B41J2/155 ,  B41J2/2054 ,  B41J2/2146

摘要： A method for carrying out a printing operation on an inkjet printing machine compensates for failed printing nozzles by using a computer. After a screening process in which a halftone image is created for an image to be printed, failed printing nozzles are compensated for by increased ink application from neighboring printing nozzles by precalculating at least one corrective halftone image for the adjacent printing nozzles by using the computer, replacing the halftone image created in the screening process by the corrective halftone image in the at least one column of the neighboring printing nozzles, and carrying out the printing operation on the inkjet printing machine using the corrected halftone.

公开(公告)号：US20200094575A1

公开(公告)日：2020-03-26

申请号：US16580588

申请日：2019-09-24

申请人： HEIDELBERGER DRUCKMASCHINEN AG

发明人： AXEL HAUCK ,  ILIAS TRACHANAS ,  BERND STRITZEL ,  FLORIAN KLOEPPNER

IPC分类号： B41J2/21

摘要： A computer-assisted method for compensating for position-dependent density fluctuations in printing nozzles of inkjet printing heads in an inkjet printing machine includes implementing pre-compensation for all color separations of a print image during the halftoning process in the pre-print department on the basis of a pre-defined density compensation profile by using a pre-print computer. Online compensation is implemented for all color separations of the now pre-compensated print image during an on-going production run for producing the print image on the basis of a re-calculated density compensation profile by using a control unit of the inkjet printing machine.

公开(公告)号：US20190351674A1

公开(公告)日：2019-11-21

申请号：US16387061

申请日：2019-04-17

申请人： HEIDELBERGER DRUCKMASCHINEN AG

发明人： BERND STRITZEL

IPC分类号： B41J2/045 ,  B41J2/21

摘要： A method for compensating for position-dependent density fluctuations in an inkjet printing machine includes the steps of assigning, by using a look-up table, specific halftone patterns to specific gray values of a color separation to be screened of an image in the course of the calibration of a raster image processor of the inkjet printing machine, using the halftone patterns in the image screening process by using the computer and printing the halftone image on the inkjet printing machine. The look-up table contains the position of every printing nozzle of the print heads in the inkjet printing machine as an additional variable and the computer enters a complete set of gray values with associated adapted halftone patterns into the look-up table for every position of a printing nozzle.