Print data generating configuration that enables an image print to have a tolerance for image quality degradation against variations of print characteristics between printing elements of a print head

#1. Field of the Invention

#The present invention relates to an image processing apparatus, a printing apparatus, and an image processing method, and particularly, to a print data generating configuration that enables an image print to have a tolerance for image quality degradation against variations of print characteristics between printing elements of a print head, a fluctuation in scanning of the print head, a conveying error of a print medium and the like.

#2. Description of the Related Art

#FIG. 1 is a perspective view showing the construction of an inkjet printing apparatus using a full line type print head according to a third embodiment of the present invention;

#FIG. 2 is a diagram showing an example of a mask pattern used in a multi-pass print for completing a print by twice scans in a serial print system;

#FIG. 3 is diagrams showing an arrangement of print pixels in binary image data according to the conventional example and the result obtained by distributing the print pixels to twice scans according to the method described in Japanese Patent Laid-Open No. H06-191041 (1994);

#Hereinafter, embodiments of the present invention will be in detail explained with reference to the drawings. It should be noted that the embodiments explained hereinafter relate to an inkjet printing apparatus. However, the present invention can achieve the effect even in an apparatus other than the inkjet printing apparatus as long as the apparatus forms an image in a dot alignment system using a plurality of printing elements.

#FIG. 6 is a perspective view explaining a schematic structure of a serial type inkjet printing apparatus used in a first embodiment of the present invention. A print head 105 is mounted on a carriage 104 that moves at a constant speed in a main scan direction and ejects ink according to print data in a frequency corresponding to the constant speed. When one time of scan is completed, a conveying roller 704 and an auxiliary roller 703 rotate and a print medium P held between these rollers and between a feeding roller 705 and an auxiliary roller 706 is conveyed in a sub scan direction by an amount corresponding to a print width by the print head 105. This scan and the conveying operation are intermittently repeated to print an image on the print medium P step by step.

#The print head 105 includes print heads of black (K), cyan (C), magenta (M) and yellow (Y) which are located in a main scan direction shown in the figure and plurality of ejection openings are arranged in a sub scan direction in the print heads of the respective colors.