Abstract: The contamination by ink of an ink jet printing system at start-up and shut-down is eliminated by moving the normal operational gutter from its print position along the flight path of the ink droplets to a position immediately adjacent to the nozzle plate of said head. The charge electrodes and the deflection electrode are moved out of the path of the gutter as it advances towards the nozzle plate.

Abstract: During the startup and/or shutdown cycle of an ink jet printer, a movable probe in the form of a thin hollow tube, is inserted into the flight path of the ink droplets. The tube is normally positioned relative to the droplets flight path. At the shutdown cycle, the charge electrode is removed from the vicinity of the jet streams. The undeflected droplets are caught by the hollow tube. The tube is then moved to a position next to the nozzle plate. The ink jet printer head may then be turned off and all ink is caught in the tube. At startup the sequence is reversed until the tube is back at its normal position.