Unlike traditional Large Format Printers, with a scanning printing carriage that stops in a Service Station for Printhead Servicing, the new HP Large Format PageWide Array Printer has numerous Mechanisms that move to the Printheads to perform Maintenance tasks: These are the Fast Spittoon, Service Carriage, Blow Primer and Capping Station. The Spittoon permits simultaneous spitting of all Nozzles inside a reservoir that has the capability to extract waste ink into an offline container. This reservoir, the spit during massive spit operations a lot of aerosol is generated inside the spittoon but it is also controlled and collected to prevent it from travelling into sensitive printer elements. The printer has a Servicing Carriage that moves along the Printbar axis , where the Printheads are placed, that features a User Consumable Cloth Cleaning mechanism (aka Wiper) capable of performing 500 wipe full span operations before replacement. It also houses a Drop Detector to measure nozzle health along the Printbar that closes the loop and permits a customized servicing strategy. Finally, it has an Optical Sensor focusing the Printzone with which Alignment and color consistency calibrations are performed. This sensor allows us to calibrate media advance parameters and others like side edges, top and bottom of form. In the event of severe issues like air ingestion, pigment settling or clogging a Blow Primer that is built in the each of the Printheads latching mecahnism can flush large amounts of ink out the nozzles at a pressure as high as that provided by the Ink Delivery System. Each Printhead is primed individually. Last of all, the printer has a Printhead storage device called Capping System that provides maintenance of the moisture levels in the nozzles to ensure readiness to print and long term Nozzle health and protection.
Rafael Ulacia, "HP Large Format PageWide Array Printer servicing Hardware" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP31), 2015, pp 242 - 245, https://doi.org/10.2352/ISSN.2169-4451.2015.31.1.art00054_1