Self-cleaning wet wipe method and apparatus for cleaning orifices in an aip type printhead

Abstract

In order to clean a dirty printhead, the dirty printhead is first capped and the ink pressure in the printhead increased significantly to allow ink to escape through the orifices and completely fill a small gap inside the cap portion. After letting the orifices soak for a predetermined time to dissolve the dried ink and loosen dust debris which may be found on the printheads, the cap drainhole is opened to drain the ink while keeping the ink pressure inside the head at an intermediate higher level. Dirty ink remaining inside the orifice bore is removed using a self cleaning wiping station in separate steps. During a first step, the wiping element is pressed into contact with the orifices. The dirty ink, because of the high pressure inside the printhead, is unable to reenter the printhead and is absorbed by the wiping element. In a second step, the pressure inside the printhead is decreased significantly below operating pressures to enable the menisci to retreat inside an orifice lip. Then the orifices are again wiped with another portion of the wiping element to remove any remaining ink and to assist in drying the printhead. Once the printhead has been cleaned, the wiping station is moved out of engagement with the printhead and the wiping station automatically cleans the wiping element by passing the wiping element through the washing fluid and the squeegee element until absorbed ink is removed from the wiping element.