Patent ID: 7641322
Filing Date: 2010-01-05
Classification: B41J

Abstract:
1. A printing apparatus comprising: a substrate having a flat surface: a common liquid chamber that stores electrically conductive liquid and has a plurality of deriving ports; a plurality of liquid transfer paths extending from the common liquid chamber to a print medium, the plurality of liquid transfer paths provided on the flat surface of the substrate; a liquid deriving unit that selectively derives liquid from the common liquid chamber to the plurality of liquid transfer paths, the liquid deriving unit comprising: a plurality of first electrodes, respectively provided near to the deriving port, corresponding to the plurality of liquid transfer paths; a first voltage applying unit that selectively applies a voltage to the plurality of first electrodes; and a first insulating film provided on surfaces of the plurality of first electrodes and configured to reduce, when the first voltage applying unit applies a voltage to one of the first electrodes, liquid repellency of a part corresponding to the one of the first electrodes in comparison with liquid repellency of the part in a state in which no voltage is applied to the one of the first electrodes; a liquid transfer unit that transfers the liquid, which is derived to the liquid transfer path, to the print medium; and a liquid transfer controlling unit that controls the liquid deriving unit and the liquid transfer unit; wherein the liquid transfer unit comprises: a plurality of second electrodes arranged along each of the liquid transfer paths from a corresponding one of the plurality of first electrodes, the plurality of second electrodes provided on the flat surface of the substrate; a second voltage applying unit that selectively applies a voltage to the plurality of second electrodes; and a second insulating film provided on surfaces of the plurality of second electrodes and configured to reduce, when the second voltage applying unit applies a voltage to one of the second electrodes, liquid repellency of a part corresponding to the one of the second electrodes in comparison with liquid repellency of the part in a state in which no voltage is applied to the one of the second electrodes; wherein the liquid transfer controlling unit controls the second voltage applying unit so that a voltage is sequentially applied to the plurality of second electrodes along the liquid transfer paths; wherein the plurality of liquid transfer paths extend in parallel to a first direction; and the plurality of second electrodes provided on the plurality of liquid transfer paths are arranged in a second direction perpendicular to the first direction and are disposed on a plane in a matrix form; and wherein liquid repellency of areas between the plurality of liquid transfer paths remains unchanged as viewed in a direction perpendicular to the flat surface of the substrate such that liquid does not move on the areas over the liquid transfer path.