Patent ID: 7832836
Filing Date: 2010-11-16
Classification: B41J

Abstract:
1. An ink jet printing apparatus that causes a printing head to eject ink to a printing medium to perform printing, said apparatus comprising: scanning means for performing a forward scan and a backward scan of the printing head along a main scanning direction; conveying means for conveying the printing medium in a direction intersecting with the main scanning direction; the print head on which a plurality of nozzle arrays, each of which has a plurality of nozzles arranged, are arranged in the main scanning direction, said print head having a plurality of nozzle arrays for cyan, magenta, and yellow inks which nozzle arrays are symmetrical with respect to an axis perpendicular to the main scanning direction, and said print head having a nozzle array for pigment black ink and nozzle arrays for dye black ink which are arranged to be in an asymmetrical position with respect to other color nozzle arrays, wherein the nozzle arrays for dye black ink are arranged so that the nozzle arrays for dye black ink and the nozzle arrays for cyan, magenta and yellow inks are capable of being used for printing a same area in one scan of the print head, wherein a width of the nozzle array for pigment black ink in a nozzle arrangement direction is longer than that of the nozzle arrays for cyan, magenta, yellow and dye black inks, and wherein the nozzle array for pigment black ink is located at a different position in the nozzle arrangement direction than the nozzle arrays for cyan, magenta, yellow and dye black inks; and control means for performing printing on the printing medium by causing a printing operation in which printing is performed during the scan of the print head by said scanning means and a conveying operation in which conveying of the printing medium by said conveying means to be repeated alternately to perform printing on the printing medium, wherein said control means is capable of performing printing of a first print mode, which completes printing on a predetermined area of the printing medium with one scan of the printing head, and performing printing of a second print mode, which completes printing on a same predetermined area of the printing medium with a plurality of scans of the printing head and causes the conveying operation with a smaller conveying amount of the printing medium in one conveying operation by said conveying means than that in the first print mode, and wherein said control means performs printing using only the nozzle arrays for cyan, magenta, yellow and pigment black inks in the first mode and performs printing using the nozzle arrays for cyan, magenta, yellow, and dye black inks in the second print mode.