Ink jet printing method, ink jet printing apparatus, and ink jet head

An ink jet printing apparatus comprising:

• a heater configured to heat a printing medium that is poorly or not absorbent of ink,
• an ink jet head operable to eject inks and a treatment liquid acting to flocculate one or more constituents of the inks while scanning the printing medium in a scanning direction a plurality of times, the ink jet head including:
• first ink nozzles to be filled with an ink, the first nozzles being arranged in a sub-scanning direction intersecting the scanning direction;
• second ink nozzles to be filled with an ink having a different composition from the ink of the first ink nozzles, the second ink nozzles being arranged in the sub-scanning direction;
• and
• treatment liquid nozzles to be filled with the treatment liquid, the treatment liquid nozzles being arranged in the sub-scanning direction, at least some of the treatment liquid nozzles being coincident in position in the sub-scanning direction with the first and the second ink nozzles,
• wherein the first ink nozzles are the closest of the ink nozzles to the treatment liquid nozzles in the scanning direction, and the second ink nozzles are arranged opposite the treatment liquid nozzles in the scanning direction with respect to the first ink nozzles,
• wherein the treatment liquid nozzles are in an arrangement in the central one-third in the scanning direction of all the nozzles,
• wherein the heater is configured to heat the printing medium so that the ink of the first ink nozzles, the ink of the second ink nozzles, and the treatment liquid are each ejected onto a heated printing medium,
• wherein when the ink of the first ink nozzles is mixed with a solution of 5% by mass of calcium acetate in water in a ratio of 2:1, the ink of the first ink nozzles exhibits a viscosity increased by a factor of 6.0 or less relative to the viscosity before being mixed,
• wherein when the ink of the second ink nozzles is mixed with a solution of 5% by mass of calcium acetate in water in a ratio of 2:1, the ink of the second ink nozzles exhibits a viscosity increased by a factor of more than 6.0 relative to the viscosity before being mixed.

An ink jet head operable to eject inks and a treatment liquid acting to flocculate one or more constituents of the inks while scanning a printing medium that is poorly or not absorbent of ink in a scanning direction a plurality of times, the ink jet head comprising:

• a heater configured to heat the printing medium,
• first ink nozzles to be filled with an ink, the first nozzles being arranged in a sub-scanning direction intersecting the scanning direction;
• second ink nozzles to be filled with an ink having a different composition from the ink of the first ink nozzles, the second ink nozzles being arranged in the sub-scanning direction;
• and
• treatment liquid nozzles to be filled with a treatment liquid, the treatment liquid nozzles being arranged in the sub-scanning direction, at least some of the treatment liquid nozzles being coincident in position in the sub-scanning direction with the first and the second ink nozzles,
• wherein the first ink nozzles are the closest of the ink nozzles to the treatment liquid nozzles in the scanning direction, and the second ink nozzles are arranged opposite the treatment liquid nozzles in the scanning direction with respect to the first ink nozzles,
• wherein the treatment liquid nozzles are in an arrangement in the central one-third in the scanning direction of all the nozzles,
• wherein the heater is configured to heat the printing medium so that the ink of the first ink nozzles, the ink of the second ink nozzles and the treatment liquid are each ejected onto a heated printing medium,
• wherein when the ink of the first ink nozzles is mixed with a solution of 5% by mass of calcium acetate in water in a ratio of 2:1, the ink of the first ink nozzles exhibits a viscosity increased by a factor of 6.0 or less relative to the viscosity before being mixed, and
• wherein when the ink of the second ink nozzles is mixed with a solution of 5% by mass of calcium acetate in water in a ratio of 2.1, the ink of the second ink nozzles exhibits a viscosity increased by a factor of more than 6.0 relative to the viscosity before being mixed.