A digital printing system includes a print head and a processor. The print head is configured to jet droplets of ink. The a processor is further configured to translate a required shade of a color, to be printed at a given location on a substrate by the print head, into a sequence of pulses, the sequence including: (a) up to a predefined maximum number of driving pulses that cause the print head to jet respective droplets, and (b) a tickling pulse, which has a smaller amplitude than the driving pulses and which causes the print head to jet a droplet smaller than the droplets jetted in response to the driving pulses. The processor is additionally configured to apply the sequence of pulses to the print head.

A digital printing system (10) includes a print head (622) and a processor (20). The print head is configured to jet droplets of ink. The processor is further configured to translate a required shade of a color, to be printed at a given location on a substrate by tire print head, into a sequence of pulses (625, 630), the sequence including: (a) up to a predefined maximum number of driving pulses (625) that cause the print head to jet respective droplets, and (b) a tickling pulse (630), which has a smaller amplitude than the driving pulses and which causes the print head to jet a droplet smaller than the droplets jetted in response to the driving pulses. The processor is additionally configured to apply the sequence of pulses to the print head.

In an image processing device, a controller performs: acquiring target image data representing a target image; inputting first and second datasets into a machine learning model and causing the machine learning model to output first and second partial dot data; and generating dot data specifying a dot formation state for each of a plurality of pixels in a print image corresponding to the target image using the first and second partial dot data. The first dataset includes first partial image data and a first value for an input parameter. The second dataset includes second partial image data and a second value for the input parameter. The machine learning model outputs the second partial dot data different from the first partial dot data according to the second value being different from the first value even when the second partial image data is identical to the first partial image data.

A printing apparatus includes a head that discharges ink droplets, and a control unit that performs discharge control of the head. When printing a boundary region formed by an end portion of a first image and an end portion of a second image that is lighter than the first image, in discharge control of a specific ink, among a plurality of inks for printing the end portion of the first image, that exhibits lightness, when forming the end portion of the first image, lower than lightness of the end portion of the second image by a predetermined value or more, the control unit performs specific ink discharge control to cause a number of dots per unit area constituting the end portion of the first image to be smaller than a number of dots per unit area constituting a normal portion, of the first image, that is adjacent to the end portion of the first image.

Techniques for reducing or eliminating image banding in an ink-jet image are provided. In an example, a method of operating a printer to reduce or eliminate image banding can include generating command profile for printing a given image, applying a filter to the command profile to provide a filtered profile, and dispensing ink from a printhead of the printer based on the filtered profile. In certain examples, the filter can randomize droplet sizes of ink dispensed while executing the printing to reduce or eliminate image banding.

There is provided an ink jet recording apparatus including an ink jet head and a drive circuit. The ink jet head forms an image on a recording medium in response to a drive signal applied to multiple piezoelectric elements. The drive signal causes multiple pressure chambers corresponding to the multiple piezoelectric elements to expand or to contract in volume and causes ink in the multiple pressure chambers to be discharged from multiple nozzles. The drive circuit generates a drive signal for discharging multiple liquid droplets to one pixel for combining the multiple liquid droplets together and applies the drive signal to each of the multiple piezoelectric elements of the ink jet head. The drive signal includes multiple discharge pulses which make velocities of tips of respective liquid columns substantially same after a predetermined time from starting of ink discharge from the nozzles.

A digital printing system includes a print head and a processor. The print head is configured to jet droplets of ink. The a processor is further configured to translate a required shade of a color, to be printed at a given location on a substrate by the print head, into a sequence of pulses, the sequence including: (a) up to a predefined maximum number of driving pulses that cause the print head to jet respective droplets, and (b) a tickling pulse, which has a smaller amplitude than the driving pulses and which causes the print head to jet a droplet smaller than the droplets jetted in response to the driving pulses. The processor is additionally configured to apply the sequence of pulses to the print head.

In a printing apparatus, in a first mode a head ejects a first type of liquid onto a printing medium and an energy applying device applies energy to the first type of liquid to form a background, and subsequently the head ejects a second type of liquid onto the background and the energy applying device applies energy to the second type of liquid on the background so that an image is formed on the background. In a second mode the head ejects the second type of liquid onto the printing medium without forming a background, and the energy applying device applies energy to the second type of liquid. The controller performs setting a quantity of the second type of liquid to be used in the first mode, to be greater than a quantity of the second type of liquid to be used in the second mode.

An liquid ejecting device includes an inkjet head, a scanning driving unit, a storage, an influence degree storage that stores influence degree information, and a control unit. The influence degree information indicates a magnitude of an influence generated at one ejection position by forming dots of the liquid at each of a plurality of ejection positions. The control unit causes other nozzles to eject a larger amount of liquid than at a normal time with respect to at least a part of the ejection position where the liquid is ejected by the other nozzles in the vicinity of an abnormal nozzle at the time of main scan, and selects an ejection position to which the other nozzle ejects a larger amount of the liquid than the normal time based on the influence degree information.

Techniques for reducing or eliminating image banding in an ink-jet image are provided. In an example, a method of operating a printer to reduce or eliminate image banding can include generating command profile for printing a given image, applying a filter to the command profile to provide a filtered profile, and dispensing ink from a printhead of the printer based on the filtered profile. In certain examples, the filter can randomize droplet sizes of ink dispensed while executing the printing to reduce or eliminate image banding.