Draft printing with multiple same-hue ink nozzles

A printing apparatus for forming ink dots on a print medium during main scan, comprising:

• a print head having a same-hue nozzle group for ejecting a plurality of same-hue inks having the substantially same hue and different in at least one of lightness and saturation, the same-hue nozzle group including a plurality of same-ink nozzle sub-groups arranged at mutually staggered positions in sub-scan direction, each of the same-ink nozzle sub-groups ejecting a same ink;
• and
• a print data generator configured to generate a print data configured to form ink dots on mutually different main scan lines with the respective same-ink nozzle sub-groups during each main scan in a predetermined fast printing mode;
• and
• a printing unit configured to form ink dots with the print head on the print medium in response to the generated print data.

A computer program product for causing a computer to generate print data to be supplied to a printing unit to form ink dots on a print medium during main scan, wherein

• the printing unit comprises a print head having a same-hue nozzle group for ejecting a plurality of same-hue inks having the substantially same hue and different in at least one of lightness and saturation, the same-hue nozzle group including a plurality of same-ink nozzle sub-groups arranged at mutually staggered positions in sub-scan direction, each of the same-ink nozzle sub-groups ejecting a same ink;
• and
• the computer program product comprising:
• a computer readable medium;
• and
• a computer program stored on the computer readable medium, the computer program comprising a first program for causing the computer to generate a print data configured to form ink dots on mutually different main scan lines with the respective same-ink nozzle sub-groups during each main scan in a predetermined fast printing mode.

The computer program product in accordance with 19, wherein

• the print head is capable of ejecting M types of inks, the M types of inks having N different hues, N being an integer of at least 1, M being an integer of at least N+1;
• the computer program further comprising:
• a second program for causing the computer to convert a color system of image data indicative of a image to be printed to generate converted image data represented with a plurality of color components;
• and
• a third program for causing the computer to generate dot data from the converted image data, the dot data representing a state of dot formation at each pixel for the plurality of color components;
• wherein the second program is configured to execute in the fast print mode such that the converted image data is represented with N color components of the N hues, without distinguishing the plurality of same-hue inks.

The computer program product in accordance with 19, wherein

• the print head is capable of ejecting M types of inks, the M types of inks having N different hues, N being an integer of at least 1, M being an integer of at least N+1;
• the computer program further comprising:
• a second program for causing the computer to convert a color system of image data indicative of a image to be printed to generate converted image data represented with M types of color components corresponding to the M types of ink;
• a third program for causing the computer to generate dot data from the converted image data, the dot data representing a state of dot formation at each pixel for the M types of color components;
• and
• a fourth program for causing the computer to convert the dot data to converted dot data by performing logical addition of the dot data corresponding to the plurality of same-hue inks at each pixel, the converted dot data representing a state of dot formation at each pixel for the N color components of the N hues in the fast print mode.

The computer program product in accordance with 19, wherein

• the print head is capable of ejecting M types of inks, the M types of inks having N different hues, N being an integer of at least 1, M being an integer of at least N+1;
• the computer program further comprising:
• a second program for causing the computer to convert a color system of image data indicative of a image to be printed to generate converted image data represented with M types of color components corresponding to the M types of ink;
• a third program for causing the computer to generate dot data from the converted image data, the dot data representing a state of dot formation at each pixel for the M types of color components;
• a fourth program for causing the computer to convert the print data from the dot data, the print data including raster line data representing a status of ink ejection from each nozzle during each main scan;
• and
• a fifth program for causing the computer to convert the raster line data to converted raster line data by performing logical addition of the raster line data corresponding to the plurality of same-hue inks at each pixel, the converted raster line data representing a status of ink ejection from each nozzle during each main scan for the N color components of the N hues in the fast print mode.