Ink-jet head and ink-jet printer having ink-jet head

An ink-jet printer including an ink-jet head, said ink-jet head comprising:

• a passage unit including a plurality of pressure chambers each connected with a nozzle and arranged in a matrix in a plane to form a plurality of pressure chamber rows in a first direction in said plane;
• and
• a plurality of common ink passages each extending along said first direction and communicating with said pressure chambers,
• wherein said pressure chamber rows include first pressure chamber rows each constituted by pressure chambers each connected with a nozzle deviated on one side thereof with respect to a second direction crossing said first direction, and second pressure chamber rows each constituted by pressure chambers each connected with a nozzle deviated on another side thereof with respect to said second direction, when viewing from a third direction perpendicular to said plane, and
• each of said common ink passages including at least a boundary region between one of said first pressure chamber rows and one of said second pressure chamber rows neighboring each other so that the nozzles connected with the pressure chambers in each of the pressure chamber rows face outward when viewing from said third direction, and none of said common ink passages overlap any of said nozzles.

An ink-jet head comprising:

• a plurality of nozzles for ejecting ink;
• a plurality of pressure chamber rows each constituted by a plurality of pressure chambers each having a substantially parallelogrammic shape in a plan view and arranged adjacent to each other, each of said pressure chambers connected with one of said nozzles;
• and
• first and second common ink passages disposed in parallel with each other so as to extend over said plurality of pressure chamber rows, each of said first and said second common ink passages communicating with one of said pressure chambers, wherein
• each of said pressure chamber rows comprising:
• a first pressure chamber communicating with said first common ink passage at one acute portion and with a first nozzle at an other acute portion;
• a second pressure chamber neighboring said first pressure chamber on the side of said other acute portion communicating with said first nozzle, said second pressure chamber communicating with said first common ink passage at one acute portion facing said first pressure chamber and with a second nozzle at an other acute portion;
• a third pressure chamber neighboring said second pressure chamber on the side of said other acute portion communicating with said second nozzle, said third pressure chamber communicating with a third nozzle at one acute portion facing said second pressure chamber and with said second common ink passage at an other acute portion;
• and
• a fourth pressure chamber neighboring said third pressure chamber on the side of said other acute portion communicating with said second common ink passage, said fourth pressure chamber communicating with a fourth nozzle at one acute portion facing said third pressure chamber and with said second common ink passage at an other acute portion, wherein said first, second, third, and fourth nozzles being disposed between said first and second common ink passages in a plane where said plurality of pressure chamber rows are formed.

An ink-jet head comprising:

• a plurality of nozzles for ejecting ink;
• a plurality of pressure chamber rows each constituted by a plurality of pressure chambers each having a substantially parallelogrammic shape in a plan view and arranged adjacent to each other, each of said pressure chambers connected with one of said nozzles;
• and
• first common ink passages disposed in parallel with each other so as to extend over said plurality of pressure chamber rows, each of said first common ink passages communicating with one of said pressure chambers, wherein
• each of said pressure chamber rows comprising:
• a first pressure chamber communicating with said first common ink passage at one acute portion and with a first nozzle at an other acute portion;
• and
• a second pressure chamber neighboring said first pressure chamber on the side of said one acute portion communicating with said first common ink passage, said second pressure chamber communicating with said first common ink passage at one acute portion facing said first pressure chamber and with a second nozzle at an other acute portion, wherein said first common ink passages being disposed between said first and second nozzles in a plane where said plurality of pressure chamber rows are formed.

An ink-jet head, comprising:

• a plurality of nozzles for ejecting ink;
• a plurality of common ink passages extending in parallel with each other;
• a plurality of pressure chambers each having a substantially parallelogrammic shape with corners rounded in a plan view, each of said pressure chambers having one end communicating with one of said nozzles and an other end communicating with one of said common ink passages;
• a plurality of parallelogrammic regions each having a substantially similar shape in a plan view to that of said pressure chambers and including one of said pressure chambers, said parallelogrammic regions being arranged two-dimensionally;
• and
• an actuator unit for generating pressure in one of said pressure chambers so that ink supplied through one of said common ink passages is ejected through one of said nozzles, wherein
• said plurality of parallelogrammic regions comprises a first parallelogrammic region having a first nozzle at one acute portion, a second parallelogrammic region neighboring said first parallelogrammic region on the first nozzle side and having a second nozzle at an acute portion on the opposite of the side facing said first parallelogrammic region, a third parallelogrammic region neighboring said second parallelogrammic region on the second nozzle side and having a third nozzle at an acute portion on the side facing said second parallelogrammic region, and a fourth parallelogrammic region neighboring said third parallelogrammic region on the side opposite to the third nozzle and having a fourth nozzle at an acute portion on the side facing said third parallelogrammic region, wherein said first, second, third, and forth parallelogrammic regions are arranged neighboring each other in a direction at an acute angle with an extension direction of said common ink passages so as to share one of its hypotenuses with each other, and
• each of said common ink passages are disposed close to at least one of said first and fourth nozzles.