Patent ID: 7125097
Filing Date: 2006-10-24
Classification: B41J

Abstract:
1. An ink-jet printing head comprising a cavity unit and an actuator which are superposed on each other, wherein said cavity unit is a laminar structure including a plurality of plates superposed on each other in a vertical direction of said cavity unit, and has (a) a plurality of nozzles which are open in a surface thereof that is to be opposed to a print media and which are arranged in at least one row, (b) a plurality of pressure chambers which are arranged in at least one row parallel to said at least one row of said nozzles, (c) a plurality of communication passages for communication between the respective pressure chambers and the respective nozzles, and (d) a manifold portion which stores an ink supplied from an ink supply source and re-fills the pressure chambers, wherein said actuator has a plurality of active portions which correspond to said pressure chambers, respectively, and which are selectively operable to eject the ink from the corresponding nozzles, wherein said pressure chambers arranged in each of said at least one row are spaced apart from each other by a first spacing pitch, except at least one adjacent pair of said pressure chambers of said at least one row which are spaced apart from each other by a second spacing pitch that is larger than said first spacing pitch, wherein a spacing pitch of all adjacent pairs of said nozzles arranged in each of said at least one row is substantially the same, and wherein each of said communication passages includes at least one horizontally extending portion which extends in parallel with a horizontal direction of said cavity unit.