Ink-jet printing head in which each passage between pressure chamber and nozzle includes horizontally extending portion

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 a direction of 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 are arranged with a first spacing pitch between each adjacent pair of said pressure chambers, except at least one adjacent pair of said pressure chambers which are spaced apart from each other by a second spacing pitch that is larger than said first spacing pitch,
• wherein each of said communication passages consist of at least one horizontally extending portion which extends in parallel with a horizontal direction of said cavity unit, and at least one vertically extending portion which extends in parallel with said vertical direction of said cavity unit,
• and wherein each of said at least one horizontally extending portion extends in a direction inclined with respect to said direction of said at least one row of said nozzles.

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 extend in the vertical direction of said cavity unit, 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 nozzles arranged in each of said at least one row are spaced apart from each other by a first spacing pitch, while at least one adjacent pair of said pressure chambers arranged in each of said at least one row are spaced apart from each other by a second spacing pitch that is larger than said first spacing pitch,
• 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.