Abstract: Example implementations relate to a method to manage printhead operational life; the method comprising firing at least one nozzle of a printhead according to an associated firing parameter to produce a respective drop of print liquid, measuring a parameter associated with the drop of print liquid, and adjusting the firing parameter in response to the measuring to reduce the measured parameter associated with the drop of print liquid on a subsequent firing while maintaining the firing parameter at or above a predetermined parameter limit to maintain print image quality.

Abstract: Disclosed herein is a spittoon assembly for a printing device, a printing device comprising a spittoon assembly, and a method of cleaning a print head using a spittoon assembly. The spittoon assembly comprises a waste receptacle and a spit plate with a receiving surface. The receiving surface is inclined relative to a horizontal direction by an inclination angle when the spittoon assembly is mounted in the printing device. A fluid path extends from the receiving surface to the waste receptacle.

Abstract: An example method comprises operating a drive unit to advance a substrate in a substrate advance direction toward a printing station. At the printing station, a first line is printed onto the substrate. A drive unit is instructed to advance the substrate in the substrate advance direction by a target amount, and a second line is printed onto the substrate. The distance between the first and second lines in a direction perpendicular to the substrate advance direction is calculated and, based on the calculated difference, a tension of the substrate is modified.

Abstract: Examples relate to a computer implemented method comprising, based on a vulnerable nozzle map indicating one or more operational nozzles of a printhead identified as meeting a failure likelihood criterion, during a print job, and between successive print passes of the printhead, checking operation of the one or more operational nozzles indicated on the vulnerable nozzle map.

Abstract: Example implementations provide a controller comprising circuitry to align a substrate; the controller comprising: circuitry to control varying the tension of an unspooled portion of the substrate between a spool bearing the substrate and a pinch roller; said circuitry comprising circuitry to control varying the pinch load exerted by the pinch roller on the unspooled portion of the substrate.

Abstract: In an example, a printing apparatus includes a controller, wherein the controller may be to compare a historic usage of a first printhead nozzle with a historic usage of a second printhead nozzle which is located on a same printhead as the first nozzle. The controller may be to determine that the historic usage of the first nozzle is higher than the historic usage of the second nozzle, and in response identify a currently operational third printhead nozzle, for which the second nozzle is able to compensate; and turn off the third nozzle, and operate the second nozzle at a higher firing frequency to compensate for the third nozzle.

Abstract: An example method comprises operating a drive unit to advance a substrate in a substrate advance direction toward a printing station. At the printing station, a first line is printed onto the substrate. A drive unit is instructed to advance the substrate in the substrate advance direction by a target amount, and a second line is printed onto the substrate. The distance between the first and second lines in a direction perpendicular to the substrate advance direction is calculated and, based on the calculated difference, a tension of the substrate is modified.

Abstract: Examples relate to a method to print a print job. The method comprise comparing an operational parameter of the print job with a reference operational parameter and determining to perform a maintenance task during the print job based on at least a result of comparing the operational parameter with the reference operational parameter. If the maintenance task is to be performed, the method further comprises determining a safety area on a printable medium and performing a maintenance task on a printable medium.

Abstract: An example method comprises operating a drive unit to advance a substrate in a substrate advance direction toward a printing station. At the printing station, a first line is printed onto the substrate. A drive unit is instructed to advance the substrate in the substrate advance direction by a target amount, and a second line is printed onto the substrate. The distance between the first and second lines in a direction perpendicular to the substrate advance direction is calculated and, based on the calculated difference, a tension of the substrate is modified.

Abstract: A system (300) is provided having a printer (4) to print printing liquid onto a web (6) of media (8). The system (300) has a winding roller (10) on which to roll the web (6) of media (8) after printing. A tensioner (12) to vary the tension in a portion (14) of the web (6) of media (8) is also provided. The portion (14) is a portion of web which is being rolled onto the winding roller (10). Also provided is controller (16) to control the tensioner (12) to vary the tension based on the time taken for the printed printing liquid on the web (6) of media (8) to dry.

Abstract: In one example in accordance with the present disclosure, a method, system, and non-transitory machine-readable storage medium are described. A drop characteristic measurement of a drop of print fluid ejected from a printhead is detected. The drop characteristic measurement includes at least one of a drop velocity and a drop weight. The drop characteristic measurement is compared against a threshold value. When the drop characteristic measurement is beyond the threshold value, a remedial action is triggered.

Abstract: In an example, a print apparatus includes a printhead carriage to receive a printhead comprising a print agent ejection nozzle, a drop detector to acquire a signal indicative of variations in a parameter detected by the drop detector over a period of drop detection; a memory to store nozzle location information of the nozzles; and processing circuitry comprising a correlation module to correlate the drop detector signal with the nozzle location information wherein the processing circuitry comprises an abnormality detection module to determine, based on an output of the correlation module, a cross-nozzle abnormality that affects a subset of nozzles.

Abstract: In an example, a printing apparatus includes a controller, wherein the controller may be to compare a historic usage of a first printhead nozzle with a historic usage of a second printhead nozzle which is located on a same printhead as the first nozzle. The controller may be to determine that the historic usage of the first nozzle is higher than the historic usage of the second nozzle, and in response identify a currently operational third printhead nozzle, for which the second nozzle is able to compensate; and turn off the third nozzle, and operate the second nozzle at a higher firing frequency to compensate for the third nozzle.

Abstract: The present disclosure refers to servicing printing systems, wherein the system comprises a controller to: instruct an ejection of printing fluid from each of the nozzles within a printhead; detect, by a drop detector, drops ejected from each nozzle; determine by the controller a drop time for each nozzle, being the drop time determined between the instruction of the ejection of printing fluid from each of the nozzles until the drops ejected by each of the nozzles reaches the drop detector; and determine a nozzle health parameter in view of each nozzle drop time; wherein the method comprises comparing each nozzle health parameter with a threshold value and instructing, by the controller, a servicing operation if the nozzle health parameter is outside a threshold range.

Abstract: Example implementations relate to a method to manage printhead operational life; the method comprising firing at least one nozzle of a printhead according to an associated firing parameter to produce a respective drop of print liquid, measuring a parameter associated with the drop of print liquid, and adjusting the firing parameter in response to the measuring to reduce the measured parameter associated with the drop of print liquid on a subsequent firing while maintaining the firing parameter at or above a predetermined parameter limit to maintain print image quality.

Abstract: Disclosed herein is a spittoon assembly for a printing device, a printing device comprising a spittoon assembly, and a method of cleaning a print head using a spittoon assembly. The spittoon assembly comprises a waste receptacle and a spit plate with a receiving surface. The receiving surface is inclined relative to a horizontal direction by an inclination angle when the spittoon assembly is mounted in the printing device. A fluid path extends from the receiving surface to the waste receptacle.

Abstract: Examples relate to a method to print a print job. The method comprise comparing an operational parameter of the print job with a reference operational parameter and determining to perform a maintenance task during the print job based on at least a result of comparing the operational parameter with the reference operational parameter. If the maintenance task is to be performed, the method further comprises determining a safety area on a printable medium and performing a maintenance task on a printable medium.

Abstract: An example method comprises operating a drive unit to advance a substrate in a substrate advance direction toward a printing station. At the printing station, a first line is printed onto the substrate. A drive unit is instructed to advance the substrate in the substrate advance direction by a target amount, and a second line is printed onto the substrate. The distance between the first and second lines in a direction perpendicular to the substrate advance direction is calculated and, based on the calculated difference, a tension of the substrate is modified.

Abstract: In an example, a method comprises dispensing, sequentially from each of a plurality of nozzles of a print head, a respective drop of print agent to cause a print agent drop detection apparatus to output an associated signal, and determining that one of the nozzles is dispensing in a misdirected direction based on a comparison of the signals.

Abstract: Examples of the present disclosure relate to a calibration method for a printing system. The method comprises printing a diagnostic pattern representative of decap time. The diagnostic pattern comprises the firing of nozzles after an exposure to ambient air during a first predetermined time period to produce a first pattern element and the firing of nozzles after an exposure to ambient air during a second predetermined time period to produce a second pattern element. The method includes scanning the resulting diagnostic pattern with a sensor to collect decap data in a digital form, digitally analyzing the decap data, the digital analysis comprising identifying a quantitative difference between the first and second pattern elements, and modifying a servicing process of the printing system if the quantitative difference passes a predetermined threshold.