Patent ID: 6457797
Filing Date: 2002-10-01
Classification: B41J

Abstract:
A method of controlling an ink jet printer containing a print head capable of undergoing thermal expansion in a sub-scanning direction (X), a main scanning direction (Y) and a direction normal to the plane of a recording medium (Z), said print head being movable relative to the recording medium in said main scanning direction (Y) and having a plurality of nozzles spaced apart from each other in said main scanning direction, said nozzles being energized at controlled timings for expelling ink droplets onto the recording medium, said method comprisingmeasuring at least one parameter (&Dgr;D) that is correlated to the thermal expansion of the print head, determining, for each of the nozzles, a thermally induced positional offset (&Dgr;d1 . . . &Dgr;dn) in the main scanning direction on the basis of said at least one parameter, and compensating for the offsets of the individual nozzles by controlling the timings at which the nozzles are energized.