Printing by switching sub-scan feeding between monochromatic area and color area

A printing method comprising the steps of:

• providing a print head having
• a plurality of single chromatic nozzle groups each consisting of plurality of nozzles that are arranged at nozzle pitch k×D where k is an integer of at least 2 and D is a pitch of main scan lines, the plurality of single chromatic nozzle groups being configured to eject mutually different chromatic inks, and
• an achromatic nozzle group for ejecting achromatic ink, the achromatic nozzle group consisting of a greater number of nozzles that are arranged at nozzle pitch k×D than each of the single chromatic nozzle groups;
• and
• printing images in a monochromatic area on a printing medium with the achromatic ink alone, and in a color area with the chromatic inks, the step of printing images comprising the steps of:
• (a) executing monochromatic mode printing by repeating a unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups, the unit scan operation consisting of k main scans and (k−1) sub-scans of a first feed amount, wherein the unit scan operation in the monochromatic mode printing is performed such that all dot positions in an achromatic unit band consisting of plural main scan lines without any gap therebetween are serviced by the achromatic nozzle group, and wherein a monochromatic mode sub-scan of a second feed amount is performed in each interval between each unit scan operations,
• (b) executing color mode printing by repeating the unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups while a color mode sub-scan of a third feed amount less than the second feed amount is performed in each interval between each unit scan operations, the specific achromatic nozzle group being part of the achromatic nozzle group,
• wherein the step (a) comprises:
• (a1) in a case that main scan line count Lr1 of a remaining monochromatic area is smaller than main scan line count L1 of an achromatic unit band and is larger than main scan line count L2 of a single chromatic unit band, the remaining monochromatic area being an area of the monochromatic area in which dot formation is not completed, the single chromatic unit band consisting of plural main scan lines without any gap therebetween for which a one of the single chromatic nozzle groups services with a single unit scan operation,
• performing a sub-scan of a specific feed amount so that the lowermost main scan line of the achromatic unit band comes to a lower edge of the monochromatic area when the unit scan operation is performed after the sub-scan of the specific feed amount;
• performing the unit scan operation once, while forming dots in the monochromatic area using all nozzles of the achromatic nozzle group;
• and
• proceeding to the color mode printing.

A printing method comprising the steps of:

• providing a print head having
• a plurality of single chromatic nozzle groups each consisting of plurality of nozzles that are arranged at nozzle pitch k×D where k is an integer of at least 2 and D is a pitch of main scan lines, the plurality of single chromatic nozzle groups being configured to eject mutually different chromatic inks, and
• an achromatic nozzle group for ejecting achromatic ink, the achromatic nozzle group consisting of a greater number of nozzles that are arranged at nozzle pitch k×D than each of the single chromatic nozzle groups;
• and
• printing images in a monochromatic area on a printing medium with the achromatic ink alone, and in a color area with the chromatic inks, the step of printing images comprising the steps of:
• (a) executing color mode printing by repeating a unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups, the unit scan operation consisting of k main scans and (k−1) sub-scans of a first feed amount, the specific achromatic nozzle group being part of the achromatic nozzle group, wherein a color mode sub-scan of a second feed amount is performed in each interval between each unit scan operations,
• (b) executing monochromatic mode printing by repeating the unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups while a monochromatic mode sub-scan of a third feed amount more than the second feed amount is performed in each interval between each unit scan operations,
• wherein the step (a) comprises:
• (a1) in a case that all main scan lines of a color unit band come to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed next, the color unit band consisting of plural main scan lines without any gap therebetween for which an uppermost single nozzle group services with a single unit scan operation,
• proceeding to the monochromatic mode printing.

A printing apparatus which prints images in a monochromatic area on a printing medium with an achromatic ink alone, and in a color area with chromatic inks, by ejecting ink drops from a nozzle to deposit the ink drops on the printing medium to form dots, comprising:

• a printing head having:
• a plurality of single chromatic nozzle groups each consisting of plurality of nozzles that are arranged at nozzle pitch k×D where k is an integer of at least 2 and D is a pitch of main scan lines, the plurality of single chromatic nozzle groups being configured to eject mutually different chromatic inks;
• and
• an achromatic nozzle group for ejecting achromatic ink, the achromatic nozzle group consisting of a greater number of nozzles that are arranged at nozzle pitch k×D than each of the single chromatic nozzle groups;
• and
• a main scan drive unit that moves at least one of the printing head and the printing medium to perform main scanning,
• a sub-scan drive unit that moves at least one of the printing head and the printing medium in a direction that intersects a main scanning direction to perform sub-scanning, and
• a control unit that controls each of these units,
• wherein the control unit has:
• (a) a monochromatic mode unit that executes monochromatic mode printing by repeating a unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups, the unit scan operation consisting of k main scans and (k−1) sub-scans of a first feed amount, wherein the unit scan operation in the monochromatic mode printing is performed such that all dot positions in an achromatic unit band consisting of plural main scan lines without any gap therebetween are serviced by the achromatic nozzle group, and wherein a monochromatic mode sub-scan of a second feed amount is performed in each interval between each unit scan operations,
• (b) a color mode unit that executes color mode printing by repeating the unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups while a color mode sub-scan of a third feed amount less than the second feed amount is performed in each interval between each unit scan operations, the specific achromatic nozzle group being part of the achromatic nozzle group,
• wherein the monochromatic mode unit comprising:
• a first shifting unit that
• performs a sub-scan of a specific feed amount so that the lowermost main scan line of the achromatic unit band comes to a lower edge of the monochromatic area when the unit scan operation is performed after the sub-scan of the specific feed amount;
• performs the unit scan operation once, while forming dots in the monochromatic area using all nozzles of the achromatic nozzle group;
• and
• proceeds to the color mode printing;
• in a case that a lowermost main scan line of the achromatic unit band comes to be positioned within the color area when it is assumed that the monochromatic mode sub-scan and the unit scan operation are performed next, and also that the lowermost main scan line of the achromatic unit band comes to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed.

A printing apparatus which prints images in a monochromatic area on a printing medium with an achromatic ink alone, and in a color area with chromatic inks, by ejecting ink drops from a nozzle to deposit the ink drops on the printing medium to form dots, comprising:

• a printing head having:
• a plurality of single chromatic nozzle groups each consisting of plurality of nozzles that are arranged at nozzle pitch k×D where k is an integer of at least 2 and D is a pitch of main scan lines, the plurality of single chromatic nozzle groups being configured to eject mutually different chromatic inks;
• and
• an achromatic nozzle group for ejecting achromatic ink, the achromatic nozzle group consisting of a greater number of nozzles that are arranged at nozzle pitch k×D than each of the single chromatic nozzle groups;
• and
• a main scan drive unit that moves at least one of the printing head and the printing medium to perform main scanning,
• a sub-scan drive unit that moves at least one of the printing head and the printing medium in a direction that intersects a main scanning direction to perform sub-scanning, and
• a control unit that controls each of these units,
• wherein the control unit has:
• (a) a monochromatic mode unit that executes monochromatic mode printing by repeating a unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups, the unit scan operation consisting of k main scans and (k−1) sub-scans of a first feed amount, wherein the unit scan operation in the monochromatic mode printing is performed such that all dot positions in an achromatic unit band consisting of plural main scan lines without any gap therebetween are serviced by the achromatic nozzle group, and wherein a monochromatic mode sub-scan of a second feed amount is performed in each interval between each unit scan operations,
• (b) a color mode unit that executes color mode printing by repeating the unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups while a color mode sub-scan of a third feed amount less than the second feed amount is performed in each interval between each unit scan operations, the specific achromatic nozzle group being part of the achromatic nozzle group,
• wherein the monochromatic mode unit comprising:
• a first shifting unit that
• performs a sub-scan of a specific feed amount so that the lowermost main scan line of the achromatic unit band comes to a lower edge of the monochromatic area when the unit scan operation is performed after the sub-scan of the specific feed amount;
• performs the unit scan operation once, while forming dots in the monochromatic area using all nozzles of the achromatic nozzle group;
• and
• proceeds to the color mode printing,
• in the case that main scan line count Lr1 of a remaining monochromatic area is smaller than main scan line count L1 of an achromatic unit band and is larger than main scan line count L2 of a single chromatic unit band, the remaining monochromatic area being an area of the monochromatic area in which dot formation is not completed, the single chromatic unit band consisting of plural main scan lines without any gap therebetween for which a one of the single chromatic nozzle groups services with a single unit scan operation.

A printing apparatus which prints images in a monochromatic area on a printing medium with an achromatic ink alone, and in a color area with chromatic inks, by ejecting ink drops from a nozzle to deposit the ink drops on the printing medium to form dots, comprising:

• a printing head having:
• a plurality of single chromatic nozzle groups each consisting of plurality of nozzles that are arranged at nozzle pitch k×D where k is an integer of at least 2 and D is a pitch of main scan lines, the plurality of single chromatic nozzle groups being configured to eject mutually different chromatic inks;
• and
• an achromatic nozzle group for ejecting achromatic ink, the achromatic nozzle group consisting of a greater number of nozzles that are arranged at nozzle pitch k×D than each of the single chromatic nozzle groups;
• and
• a main scan drive unit that moves at least one of the printing head and the printing medium to perform main scanning,
• a sub-scan drive unit that moves at least one of the printing head and the printing medium in a direction that intersects a main scanning direction to perform sub-scanning, and
• a control unit that controls each of these units,
• wherein the control unit has:
• (a) a color mode unit that executes color mode printing by repeating a unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups, the unit scan operation consisting of k main scans and (k−1) sub-scans of a first feed amount, the specific achromatic nozzle group being part of the achromatic nozzle group, wherein a color mode sub-scan of a second feed amount is performed in each interval between each unit scan operations,
• (b) a monochromatic mode unit that executes monochromatic mode printing by repeating the unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups while a monochromatic mode sub-scan of a third feed amount more than the second feed amount is performed in each interval between each unit scan operations,
• wherein the color mode unit comprising:
• a shifting unit that proceeds to the monochromatic mode printing, in a case that all main scan lines of a color unit band come to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed next, the color unit band consisting of plural main scan lines without any gap therebetween for which an uppermost single nozzle group services with a single unit scan operation.

A computer program product for printing images in a monochromatic area on a printing medium with the achromatic ink alone, and in a color area with the chromatic inks, using a computer, the computer being connected with a printing device having a printing head equipped with

• a plurality of single chromatic nozzle groups each consisting of plurality of nozzles that are arranged at nozzle pitch k×D where k is an integer of at least 2 and D is a pitch of main scan lines, the plurality of single chromatic nozzle groups being configured to eject mutually different chromatic inks, and
• an achromatic nozzle group for ejecting achromatic ink, the achromatic nozzle group consisting of a greater number of nozzles that are arranged at nozzle pitch k×D than each of the single chromatic nozzle groups, the computer program product comprising:
• a computer readable medium;
• and
• a computer program stored on the computer readable medium, the computer program comprising:
• (a) a monochromatic mode program for causing the computer to execute monochromatic mode printing by repeating a unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups, the unit scan operation consisting of k main scans and (k−1) sub-scans of a first feed amount, wherein the unit scan operation in the monochromatic mode printing is performed such that all dot positions in an achromatic unit band consisting of plural main scan lines without any gap therebetween are serviced by the achromatic nozzle group, and wherein a monochromatic mode sub-scan of a second feed amount is performed in each interval between each unit scan operations, and
• (b) a color mode program for causing the computer to execute color mode printing by repeating the unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups while a color mode sub-scan of a third feed amount less than the second feed amount is performed in each interval between each unit scan operations, the specific achromatic nozzle group being part of the achromatic nozzle group,
• wherein the monochromatic mode program comprises:
• a sub-program for causing the computer
• to perform a sub-scan of a specific feed amount so that the lowermost main scan line of the achromatic unit band comes to a lower edge of the monochromatic area when the unit scan operation is performed after the sub-scan of the specific feed amount;
• to perform the unit scan operation once, while forming dots in the monochromatic area using all nozzles of the achromatic nozzle group;
• and
• to proceed to the color mode printing,
• in a case that a lowermost main scan line of the achromatic unit band comes to be positioned within the color area when it is assumed that the monochromatic mode sub-scan and the unit scan operation are performed next, and also that the lowermost main scan line of the achromatic unit band comes to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed.

A computer program product for printing images in a monochromatic area on a printing medium with the achromatic ink alone, and in a color area with the chromatic inks, using a computer, the computer being connected with a printing device having a printing head equipped with

• a plurality of single chromatic nozzle groups each consisting of plurality of nozzles that are arranged at nozzle pitch k×D where k is an integer of at least 2 and D is a pitch of main scan lines, the plurality of single chromatic nozzle groups being configured to eject mutually different chromatic inks, and
• an achromatic nozzle group for ejecting achromatic ink, the achromatic nozzle group consisting of a greater number of nozzles that are arranged at nozzle pitch k×D than each of the single chromatic nozzle groups, the computer program product comprising:
• a computer readable medium;
• and
• a computer program stored on the computer readable medium, the computer program comprising:
• (a) a monochromatic mode program for causing the computer to execute monochromatic mode printing by repeating a unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups, the unit scan operation consisting of k main scans and (k−1) sub-scans of a first feed amount, wherein the unit scan operation in the monochromatic mode printing is performed such that all dot positions in an achromatic unit band consisting of plural main scan lines without any gap therebetween are serviced by the achromatic nozzle group, and wherein a monochromatic mode sub-scan of a second feed amount is performed in each interval between each unit scan operations, and
• (b) a color mode program for causing the computer to execute color mode printing by repeating the unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups while a color mode sub-scan of a third feed amount less than the second feed amount is performed in each interval between each unit scan operations, the specific achromatic nozzle group being part of the achromatic nozzle group,
• wherein the monochromatic mode program comprises:
• a sub-program for causing the computer
• to perform a sub-scan of a specific feed amount so that the lowermost main scan line of the achromatic unit band comes to a lower edge of the monochromatic area when the unit scan operation is performed after the sub-scan of the specific feed amount;
• to perform the unit scan operation once, while forming dots in the monochromatic area using all nozzles of the achromatic nozzle group;
• and
• to proceed to the color mode printing,
• in a case that main scan line count Lr1 of a remaining monochromatic area is smaller than main scan line count L1 of an achromatic unit band and is larger than main scan line count L2 of a single chromatic unit band, the remaining monochromatic area being an area of the monochromatic area in which dot formation is not completed, the single chromatic unit band consisting of plural main scan lines without any gap therebetween for which a one of the single chromatic nozzle groups services with a single unit scan operation.

A computer program product for printing images in a monochromatic area on a printing medium with the achromatic ink alone, and in a color area with the chromatic inks, using a computer, the computer being connected with a printing device having a printing head equipped with

• a plurality of single chromatic nozzle groups each consisting of plurality of nozzles that are arranged at nozzle pitch k×D where k is an integer of at least 2 and D is a pitch of main scan lines, the plurality of single chromatic nozzle groups being configured to eject mutually different chromatic inks, and
• an achromatic nozzle group for ejecting achromatic ink, the achromatic nozzle group consisting of a greater number of nozzles that are arranged at nozzle pitch k×D than each of the single chromatic nozzle groups, the computer program product comprising:
• a computer readable medium;
• and
• a computer program stored on the computer readable medium, the computer program comprising:
• (a) a color mode program for causing the computer to execute color mode printing by repeating a unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups, the unit scan operation consisting of k main scans and (k−1) sub-scans of a first feed amount, the specific achromatic nozzle group being part of the achromatic nozzle group, wherein a color mode sub-scan of a second feed amount is performed in each interval between each unit scan operations,
• (b) a monochromatic mode program for causing the computer to execute monochromatic mode printing by repeating the unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups while a monochromatic mode sub-scan of a third feed amount more than the second feed amount is performed in each interval between each unit scan operations,
• wherein the color mode program comprises:
• a sub-program for causing the computer to proceed to the monochromatic mode printing, in a case that all main scan lines of a color unit band come to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed next, the color unit band consisting of plural main scan lines without any gap therebetween for which an uppermost single nozzle group services with a single unit scan operation.