Patent ID: 6250739
Filing Date: 2001-06-26
Classification: B41J,G06K,H04N

Abstract:
Apparatus for printing a color image on a printing medium; said apparatus comprising:bidirectional scanning printhead means for scanning bidirectionally across such printing medium, to discharge color-ink droplets at ultrahigh resolution while scanning in each direction, and thereby form swaths of such color image on such printing medium in rows and columns, said rows being spaced apart by a pixel-row spacing;said printhead means including plural inkjet print-heads to print plural colors respectively, which plural printheads are mutually at least partially aligned with respect to the longitudinal direction of the printing medium; whereby the plural printheads print respective color swaths which at least partially overlap in that longitudinal direction, and wherein each printhead has nozzles spaced apart at the same spacing as the pixel rows;printing-medium advance means for intermittent operation to move such printing medium longitudinally to enable displacement, when desired, of successive swaths along such medium; andcontrol means for alternating (1) one full reciprocation of the scanning printhead means, to discharge color-ink droplets while scanning in each direction across such printing medium and back, with (2) each operation of the printing-medium advance means.