Patent ID: 6352335
Filing Date: 2002-03-05
Classification: B41J

Abstract:
A printer having, a function of bi-directional printing, for printing an image on a print medium during forward and reverse passes of main scan, the printer comprising:a print head having a plurality of nozzles and a plurality of emission driving elements for causing emission of ink droplets respectively from the plurality of nozzles, each nozzle being adaptable to form a selected one of N different dots having different sizes in one pixel area on the print medium, where N is an integer of at least 2; a main scanning drive section that effects bi-directional main scanning by moving at least one selected from the print medium and the print head; a sub-scanning drive section that effects sub-scanning by moving at least one selected from the print medium and the print head; and a head drive control section that supplies a drive signal to each of the emission driving elements responsive to a print signal, the print signal having a plurality of bits for each pixel in order to record each pixel in multiple tones, wherein the head drive control section includes a drive signal generator that is adaptable to modify a shape of the drive signal within each one-pixel period of main scan to have N different waveforms corresponding to N different values of the print signal, the N different values of the print signal representing formation of the N different dots, the drive signal generator being adaptable to change the N different waveforms of the drive signal for aligning hitting positions of ink droplets on the print medium between the forward pass and the reverse pass.