Patent ID: 8303068

Claim:
An inkjet printer comprising: a first printer head having a plurality of first nozzles and configured to eject ink from the plurality of first nozzles to a first printing area on a surface of a print medium to form first ink dots in the first printing area, the first printer head being configured to eject ink of a plurality of different colors to the first printing area; a second printer head having a plurality of second nozzles and configured to eject ink from the plurality of second nozzles to a second printing area on the surface of the print medium to form second ink dots in the second printing area, the second printer head being configured to eject ink of a plurality of different colors to the second printing area; a carriage holding the first and second printer heads and relatively movable along first and second directions with respect to the surface of the print medium, the first and second directions being perpendicular; a detector configured to detect first and second printing states in the first and second printing areas, respectively; a comparing unit configured to compare the first and second printing states detected by the detector; an ejection controller configured to control ejection from the first and second printer heads; a temperature compensator configured to compensate the ejection control performed by the ejection controller according to a temperature compensation value to make diameters of ink ejected from the first and second printer heads be substantially constant even though an ambient temperature changes, the temperature compensation value being determined corresponding to the ambient temperature, and being predetermined based on a relation between the ambient temperature and a diameter of ink drop at the ambient temperature; and a printing state compensator configured to compensate ejection control performed by the ejection controller according to a compensation value produced based on a comparison result output by the comparing unit so that the first and second printing states are substantially equal, wherein the plurality of first nozzles are provided in a first nozzle array and the plurality of second nozzles are provided in a second nozzle array, and wherein the first nozzle array is identical in configuration to the second nozzle array, and wherein the printing state compensator is configured to use an adjusted temperature compensation value as the compensation value for the ejection control of at least one of the first and the second printer heads, the adjusted temperature compensation value being a temperature compensation value corresponding to a temperature which is adjusted from the ambient temperature based on the comparison result output by the comparing unit.