Method and device for printing on a substrate by means of inkjet printing

A method for printing on a substrate by inkjet printing, in which method

• landing zones are provided on the substrate in a landing zone grid consisting of landing zone columns and landing zone rows, and
• the landing zones are each printed on using an individual pattern consisting of one or more drops by print head nozzles of a print head, wherein
• the print head nozzles and the surface of the substrate are moved relative to one another along an imaginary nozzle path during printing, wherein
• all individual patterns of a landing zone column are printed in multiple passes, wherein
• in each pass, only parts of individual patterns and/or only some of all individual patterns are printed along the nozzle path in landing zones, and
• in at least one subsequent pass, missing parts of individual patterns or further entire individual patterns are printed in incomplete or empty landing zones, and
• between the individual passes, the print head and the surface of the substrate are moved relative to one another laterally to the nozzle path by a lateral offset, wherein the print head and the surface of the substrate during printing with k interlacing passes in, in each case, n layers with at least u=k×n passes are offset relative to one another after each pass by a distance
• x
• =
• i
• ×
• a
• +
• j
• ×
• a
• k
• with i,j∈N, where a is the smallest distance between two nozzle paths, i is selected individually for each pass, or j<k, or j=1.

A device for printing on a substrate comprising a landing zone grid consisting of landing zone columns and landing zone rows, by inkjet printing, the device having:

• at least one print head comprising multiple print head nozzles spaced apart from one another at a distance, for printing in each case an individual pattern consisting of one or more drops into a landing zone of the landing zone grid by one or more print head nozzles,
• a positioning drive for moving the print head and the surface of the substrate relative to one another along an imaginary nozzle path of each of the print head nozzles and in a direction laterally to the nozzle paths, and
• a control unit for controlling the printing process, in particular the positioning drive, wherein
• the control unit is designed such that all individual patterns of a landing zone column is printed in several passes, wherein
• in each pass, only parts of individual patterns and/or only some of all individual patterns are printed along the nozzle path in landing zones, and
• in at least one subsequent pass, missing parts of individual patterns or further entire individual patterns are printed in incomplete or empty landing zones, and
• the print head and the surface of the substrate are moved relative to one another between the individual passes laterally to the nozzle path by a lateral distance, and
• a first test print is created with the print head and is checked for unwanted artefacts which are repeated in the lateral direction, wherein, when periodic lateral unwanted artefacts occur, a lateral unwanted artefact distance A is determined and, during subsequent printing of a substrate, the lateral distance x between the layers is determined by
• x
• =
• λ
• ×
• (
• i
• +
• 1
• n
• )
• with i∈N and n=number of layers and/or the lateral distance x of the passes is selected such that, in an interval of [0, λ] including λ, an average lateral position of all passes is ¼λ to ¾λ.

A device for printing on a substrate comprising a landing zone grid consisting of landing zone columns and landing zone rows, by inkjet printing, the device having:

• at least one print head comprising multiple print head nozzles spaced apart from one another at a distance, for printing in each case an individual pattern consisting of one or more drops into a landing zone of the landing zone grid by use of one or more print head nozzles,
• a positioning drive for moving the print head and the surface of the substrate relative to one another along an imaginary nozzle path of each of the print head nozzles and in a direction laterally to the nozzle paths, and
• a control unit for controlling the printing process, in particular the positioning drive, wherein
• the control unit is designed such that all individual patterns of a landing zone column is printed in several passes, wherein
• in each pass, only parts of individual patterns and/or only some of all individual patterns are printed along the nozzle path in landing zones, and
• in at least one subsequent pass, missing parts of individual patterns or further entire individual patterns are printed in incomplete or empty landing zones, and
• the print head and the surface of the substrate are moved relative to one another between the individual passes laterally to the nozzle path by a lateral distance, and
• the print head and the surface of the substrate during printing with k interlacing passes in, in each case, n layers with at least u=k×n passes are offset relative to one another after each pass by a distance
• x
• =
• i
• ×
• a
• +
• j
• ×
• a
• k
• with i,j∈N, where a is the smallest distance between two nozzle paths, i is selected individually for each pass, or j<k, or j=1.