Provided are a control unit that predicts the life of an inkjet head unit and maximizes its life to be used, and a substrate treating apparatus including the same. The control unit performs maintenance of an inkjet head unit for discharging a substrate treatment liquid onto a substrate and comprises a count module for counting the number of discharges for each nozzle of the inkjet head unit, a comparison module for comparing the number of discharges with a reference value to determine whether the number of discharges is equal to or greater than the reference value, and an evaluation module for evaluating whether a life of the inkjet head unit has reached a usable life based on whether the number of discharges of each nozzle is equal to or greater than the reference value.

A method of operating a printer distributes inkjet operations from frequently used inkjets to lesser used inkjets. The redistribution of the inkjet operations helps reduce the number of inkjets exhibiting cross-process direction error so printhead maintenance operations, such as purging, occur less frequently.

A method of operating a printer distributes inkjet operations from frequently used inkjets to lesser used inkjets. The redistribution of the inkjet operations helps reduce the number of inkjets exhibiting cross-process direction error so printhead maintenance operations, such as purging, occur less frequently.

An element substrate, comprises: a plurality of printing elements configured to discharge liquid; a plurality of first driving elements disposed in correspondence with the plurality of printing elements and configured to drive the plurality of printing elements; a plurality of heating elements configured to heat the element substrate; a plurality of second driving elements disposed in correspondence with the plurality of heating elements and configured to drive the plurality of heating elements; and a delay unit that delays timing of driving the plurality of second driving elements to drive the plurality of second driving elements at a predetermined time difference when driving the plurality of second driving elements simultaneously.

Various embodiments disclose a method for operating a printer apparatus. The method comprising monitoring a utilization rate of each heating element in a first set of heating elements defined by a print head arrangement. Further, the method comprises generating a utilization dataset based upon monitoring of the utilization rate of each heating element in the first set of heating elements print head arrangement. Furthermore, the method includes analyzing the utilization dataset to identify one or more overutilized heating elements of the first set of heating elements. Additionally, the method includes identifying a second set of heating elements defined by the print head arrangement. The second set of heating elements comprises a portion of the first set of heating elements exclusive of the one or more overutilized heating elements. The method further includes processing a print job. The processed print job utilized the second set of heating elements during printing.

A fluid ejection device includes a fluid slot, at least one fluid ejection chamber communicated with the fluid slot, a drop ejecting element within the at least one fluid ejection chamber, a fluid circulation channel communicated with the fluid slot and the at least one fluid ejection chamber, and a fluid circulating element communicated with the fluid circulation channel. The fluid circulating element is to provide on-demand circulation of fluid from the fluid slot through the fluid circulation channel and the at least one fluid ejection chamber.

An ink-jet head driving circuit includes: PMOS transistors each of which has an Nwell area, a drain terminal and a source terminal, the PMOS transistors connected to a piezoelectric element for jetting ink from a nozzle; and an NMOS transistor connected to the drain terminals of the PMOS transistors. The source terminals and Nwell areas of the PMOS transistors are connected respectively to power sources, and voltage of one of the power sources connected to the Nwell area of each of the PMOS transistors is equal to or higher than the highest voltage of the power sources connected to the source terminals of the PMOS transistors.

Various embodiments disclose a method for operating a printer apparatus. The method comprising monitoring a utilization rate of each heating element in a first set of heating elements defined by a print head arrangement. Further, the method comprises generating a utilization dataset based upon monitoring of the utilization rate of each heating element in the first set of heating elements print head arrangement. Furthermore, the method includes analyzing the utilization dataset to identify one or more overutilized heating elements of the first set of heating elements. Additionally, the method includes identifying a second set of heating elements defined by the print head arrangement. The second set of heating elements comprises a portion of the first set of heating elements exclusive of the one or more overutilized heating elements. The method further includes processing a print job. The processed print job utilized the second set of heating elements during printing.

Methods and apparatus to control a heater associated with a printing nozzle are disclosed. A method comprising controlling a heater associated with a printing nozzle to reduce a heat output of the heater based on a determination that the printing nozzle is outside a print area and printing an image on a substrate using other printing nozzles while the heat output of the heater is reduced.

A fluid ejection device includes a fluid slot, at least one fluid ejection chamber communicated with the fluid slot, a drop ejecting element within the at least one fluid ejection chamber, a fluid circulation channel communicated with the fluid slot and the at least one fluid ejection chamber, and a fluid circulating element communicated with the fluid circulation channel. The fluid circulating element is to provide on-demand circulation of fluid from the fluid slot through the fluid circulation channel and the at least one fluid ejection chamber.