US Patent 7922285 Method of cleaning a printhead using liquid foam

A method of cleaning an inkjet printhead, by generating a liquid foam on the ink ejection face such that particulate contaminants on the ejection surface disperse into the foam, then transferring the foam, together with the particulate contaminants dispersed within, onto a rotatable transfer surface moving relative said ejection face and, rotating the rotatable transfer surface into contact with a removal surface to remove the foam and the particulate contaminants dispersed within. Ink consumption is minimized by use of a foam and damage to the face is avoided since the rotatable transfer surface does not contact the face.