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: There is disclosed a printhead control method, printhead controller and printer. The method may comprise determining whether ink drop variability is likely to occur based on a first time period in which a printhead is uncovered during a print action but before printing begins, and a second time period that is a minimum period for ink drop variability to occur when the printhead is uncovered. The method may further comprise setting a printhead firing frequency for the print action based on the determination.

Abstract: A system for detecting a filling level in a printing fluid waste container comprises a waste container that collects excess printing fluid in a reservoir, and an optical sensor unit that detects a filling level of the reservoir on a filling reference surface.

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: In an example, a method includes ejecting a print agent drop from a printhead, and determining an indication of velocity of the print agent drop. A weight parameter of the print agent drop may be determined from the indication of velocity.

Abstract: A method is disclosed. The method may involve obtaining information indicative of a number of printing passes of a print head to print a swath on a printable medium. The method may comprise determining that the print head is to perform a particular printing pass which is one of: a printing pass during which an amount of print agent to be deposited from nozzles of the print head differs, by an amount that exceeds a defined threshold, from an amount of print agent to be deposited from the nozzles during a printing pass immediately preceding said particular printing pass; and a printing pass to print a swath which is the first of a plurality of adjacent swaths in which each swath has an area coverage exceeding a defined threshold. The method may comprise preparing, based on said obtained information, a schedule for a nozzle spitting procedure to commence before the print head performs the particular printing pass.

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.

Abstract: A printing system includes a feeding mechanism adapted to feed substrate from a substrate roll to a print zone, the feeding mechanism including a roller with an associated encoder configured to provide an encoder signal. A printhead is located in the print zone, and a controller configured to receive the encoder signal from the encoder, and to correlate the encoder signal to a substrate type.

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.

Abstract: It is disclosed a substrate selection method wherein the printer comprises a feeding mechanism including a feeding roller to receive a substrate roll and a media advance roller to receive a substrate from the substrate roll, the method comprising: actuating the feeding roller or the media advance roller; measuring a feeding mechanism parameter on the feeding roller or the media advance roller; calculating a substrate parameter in view of the feeding mechanism parameter; determining from a table a substrate type of in view of the substrate parameter; and selecting a preset on the printer in view of the substrate type.

Abstract: In an example a system includes a carriage with a print head receiving station, a color variation engine, and a delay engine. The color variation engine identifies a potential color variation condition corresponding to an area fill region. The delay engine applies a carriage delay strategy according to the identified potential color variation condition and the size of the area fill region.

Abstract: It is disclosed a substrate compactness detection method for a printer wherein the printer comprises a roller to receive a substrate roll and a media advance mechanism to receive a substrate from the substrate roll, the method comprising: determining a substrate thickness; advancing the substrate for a length; measuring an angular displacement of the roller caused by the advancing of the substrate; determining the substrate roll radius by using the length and the angular displacement; and calculating a compactness parameter in view of the substrate roll radius and the substrate thickness.

Abstract: A method for regulating a deposition characteristic of a rendering material in a rendering apparatus comprises determining a status of a material deposition structure, and adjusting a physical attribute of the material deposition structure.

Abstract: A system for detecting a filling level in a printing fluid waste container comprises a waste container that collects excess printing fluid in a reservoir, and an optical sensor unit that detects a filling level of the reservoir on a filling reference surface.

Abstract: In an example, a method includes ejecting a print agent drop from a printhead, and determining an indication of velocity of the print agent drop. A weight parameter of the print agent drop may be determined from the indication of velocity.

Abstract: Circuits for controlling an impeller in a fluid flow distribution system to achieve a target fluid flow are disclosed. The circuit to output a signal representative of a speed value (NT) of the impeller derived from a stored power consumption value (Wi) and speed value (Ni) pairs to achieve the target fluid flow. The circuit to receive a power signal representative of an input power consumption value (W) of the impeller at the speed value (NT) to input fluid to the fluid flow distribution system and to compare the value (W) represented by a power signal for the speed value (NT) with the stored value (Wi) and impeller speed value (Ni) pairs to determine a least difference impeller speed value (NL) of the stored pair comprising a least difference between the value (W) and the value (Wi). The circuit to output a speed signal representative of value (NL).

Abstract: A printer includes a print head to print by ejecting drops of a printing fluid;, a memory to store a correction measure, the correction measure to modify printing a pattern to compensate for decel, and a processor. The processor analyzes print data for a pattern that, when printed using the print head, triggers decel, controls the print head to eject drops of the printing fluid in accordance with the print data, when the analysis indicates that the pattern to be printed triggers decel, applies the correction measure upon printing the pattern, and, when the analysis indicates that the pattern to be printed does not trigger decel, does not apply the correction measure upon printing the pattern.

Abstract: It is disclosed a substrate selection method wherein the printer comprises a feeding mechanism including a feeding roller to receive a substrate roll and a media advance roller to receive a substrate from the substrate roll, the method comprising: actuating the feeding roller or the media advance roller; measuring a feeding mechanism parameter on the feeding roller or the media advance roller; calculating a substrate parameter in view of the feeding mechanism parameter; determining from a table a substrate type of in view of the substrate parameter; and selecting a preset on the printer in view of the substrate type

Abstract: Provided in one example is a printing system that has a printing zone with a platen (10), a drive, a suction force generator (18), a media advance sensor (26) to monitor movement of the medium through the printing zone in a medium advance direction, and a controller 28) to perform suction force calibration prior to printing. The suction force calibration includes controlling the drive to cause movement of the medium from an initial position at least partly through the printing zone while the suction force generator is controlled to generate at least one suction force level, determining a suction force level to be used during printing on the medium based on the output of the media advance sensor during the movement, and moving the medium back to the initial position.

Abstract: Herein is described a method involving a drop detector. The method may comprise: ejecting ink drops from the nozzles on a printhead toward a drop detector. A drop characteristic may then be determined from the drop detector for each ink-jet nozzle. Drop characteristics for the nozzles across the printhead may be collated into a data set, and compared with a predetermined data set for a printhead having predetermined print behaviour to determine if and how the data sets differ in terms of the pattern of drop characteristics across the printheads. If the data sets differ, a recovery strategy may be selected based how the data sets differ in terms of the pattern of drop characteristics across the printheads. A system and computer readable medium are also described herein.