Abstract: To check that nozzles of printheads 11-15 applying fixer or an ink to a print media 22 are operating correctly, the fixer or ink is applied to selected locations on a fluorescent print media which is then subjected to ultra-violet radiation; the reflectivities at these locations are detected in the visible spectrum and the information is analysed using appropriate image processing algorithms. In an ink-jet printer, for example, applied fixer may be irradiated with ultra-violet light by a source 30 and applied inks may be irradiated with visible light, with a common detector in the visible light range being employed.

Abstract: A printer apparatus comprising one or more printing elements arranged to print on print media in a print zone and a transport path arranged to transport printed sheets from the print zone to an output position, the apparatus further comprising a scanner arranged to scan a printed sheet, and diverting means arranged to selectively divert a printed sheet to the scanner, the scanner being located such that the apparatus may continue to print and transport sheets to the output position during the scanning process.

Abstract: The present invention is directed to a method and apparatus for testing the operational status of printhead nozzles. High throughput drop detection devices are used to detected ink drops that are fired from the printhead nozzles, and the operational status is determined from the ink drop characteristics. The ink drop characteristics may include the presence or absence of an ink drop. Ink drop characteristics may also include the size and the location of an ink drop. The drop detection devices are capable of detecting a plurality of ink drops that are ejected substantially simultaneously.

Abstract: A printer apparatus comprising one or more printing elements arranged to print on print media located in a print position, the apparatus further comprising first and second media paths respectively adapted to feed media to and away from the print position, the apparatus being arranged to selectively divert a print media sheet from the second media path to the print position, the apparatus being arranged to implement a servicing routine comprising marking the diverted sheet with one or more of the printing elements.

Abstract: A method for detecting clogged or otherwise anomalous nozzles in an ink jet printing device having a printer head containing at least one nozzle configured to eject droplets of ink, the method including sending an instruction to the printer head to eject droplets of ink, generating an output signal from a detecting means configured to detect a passage of droplets past the detecting means and applying an algorithm to the output signal which is configurable to check a correct functioning of the nozzles.

Abstract: The presence of invisible ink drops may be relatively easily detected on a print medium by detecting the changes in specular reflection between the print medium and the print medium upon which invisible ink drops are located. An optical sensor having a detector for capturing diffuse reflections and a detector for capturing specular reflections may be implemented to detect the presence of both sufficiently colored ink drops as well as invisible ink drops. In one respect, the location of the detected invisible inks may be utilized to determine whether an ink ejection element that fired the drops of invisible inks is offset or misaligned. In another respect, the drop size of the ink drops may be detected to determine the health of the nozzles. In this regard, the method of detecting the presence of invisible ink drops may be implemented as a routine or sub-routine to determine ink ejection element alignment, apply a positional calibration of the ink ejection element, and apply a printing mask.

Abstract: The present invention is directed to a method and apparatus for testing the operational status of printhead nozzles. High throughput drop detection devices are used to detected ink drops that are fired from the printhead nozzles, and the operational status is determined from the ink drop characteristics. The ink drop characteristics may include the presence or absence of an ink drop. Ink drop characteristics may also include the size and the location of an ink drop. The drop detection devices are capable of detecting a plurality of ink drops that are ejected substantially simultaneously.

Abstract: The presence of invisible ink drops may be relatively easily detected on a print medium by detecting the changes in specular reflection between the print medium and the print medium upon which invisible ink drops are located. An optical sensor having a detector for capturing diffuse reflections and a detector for capturing specular reflections may be implemented to detect the presence of both sufficiently colored ink drops as well as invisible ink drops. In one respect, the location of the detected invisible inks may be utilized to determine whether an ink ejection element that fired the drops of invisible inks is offset or misaligned. In another respect, the drop size of the ink drops may be detected to determine the health of the nozzles. In this regard, the method of detecting the presence of invisible ink drops may be implemented as a routine or sub-routine to determine ink ejection element alignment, apply a positional calibration of the ink ejection element, and apply a printing mask.