Abstract: An inkjet printing apparatus comprises at least one printhead which comprises at least one ink chamber and a plurality of nozzles, at least one ink container remote from the printhead, an ink delivery system comprising a source of gas under pressure operable to supply ink from said remote ink container to said ink chamber on the printhead, a priming device arranged to prime at least one printhead and comprising a connecting assembly to connect the source of gas under pressure to the printhead to be primed, and a controller to control the flow of gas through said connecting assembly to provide upon demand gas under pressure to the printhead in order to cause a flow of ink from the ink chamber through the nozzles to prime the printhead.

Abstract: In a method of printing an image on a surface, a printing system is employed which comprises a static base unit and a printing device which is moved in passes over the surface, the position of the printing device being monitored and being controlled so that printing occurs only at locations on the surface where printing has not yet been completed. The base unit and printing device have respective antennae which enable the position of the printing device on the surface to be always known. The base unit and printing device are interconnected by a flexible tube incorporating data, power and ink connections. The flexible tube may also convey pressurized air to produce an air cushion which maintains the printing device at a constant spacing from the surface to the printhead. Printing may occur in two phases, firstly with a relatively large printing device and then with a relatively small printing device to fill in the gaps in coverage of the surface.

Abstract: A method and apparatus for correcting for drop placement errors due to relative rotation between an inkjet printhead mounted in a printer carriage and the print media to be printed on comprises first determining the relative contribution to the drop placement error due to rotation of the printhead about the scan axis (Y axis error), then, with respect to any determined Y axis error, applying the same magnitude and sense of correction for drop placement errors while printing in both a first scanning direction of the carriage and while printing in a second scanning direction of the carriage. Errors due to rotation about the Z axis are also corrected for. Preferably the errors are determined by printing and scanning a test pattern.