JP2001030522A - Color ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress roughness of print image quality in draft mode where dots are printed while being decimated. SOLUTION: The color ink jet printer can be operated selectively in normal print mode where all dots forming a print object dot pattern are printed or draft mode where all dots forming a print object dot pattern are printed while decimating every other dot in the main scanning direction. When the draft mode is selected, each color gradation C3-M4-Y5 of each dot D31 to be printed is formed such that it can be corrected C3-M5-Y7 in correspondence with each gradation CO-M1-Y2 of each dot D41 decimated on one adjacent side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a dot pattern to be printed and having a number N of dots forming a one-line image extending in the main scanning direction, having a number of ink jet nozzles arranged in the main scanning direction. Can be printed on the print medium held by the rotating body by one ink jet or by dividing the number of dots N into n equal parts and by n ink jets, and the gradation of each dot can be individually set. The present invention relates to a color ink-jet printer capable of performing printing by designating the same.

[0002]

2. Description of the Related Art A print head for each color in which an ink cassette is mounted is reciprocated over the entire length (full width) of a main scan (row direction), and one row (or 1 / m row) is provided during each forward movement.
Conventionally, after printing and printing one line (or 1 / m line), the printing medium (plain paper, OHP paper, etc.) is fed one line (or 1 / m line) in the sub-scanning (column) direction and repeats these. Compared to a conventional type (so-called serial type) ink jet printer, the printing speed can be greatly increased and continuous printing operation can be performed over a large number of sheets. The present applicant has proposed an ink jet printer A capable of achieving a significant downsizing (for example, Japanese Patent Application Laid-Open No. Hei 10-138520).

As shown in FIGS. 8 and 9, such a proposed printer A has a large number of ink jet nozzles arranged in the main scanning (X) direction, forms a dot pattern to be printed, and moves in the main scanning direction. The number N of dots forming a stretched one-line image is determined by one inkjet or by dividing the number N of dots into n equal parts and by n inkjets.
This is a color ink jet printer that can print all the dots of the line on the print medium held by the rotating body 5 and can print by specifying the gradation of each dot.

[0004] That is, a rotating body 5 that rotates in one direction (R direction) around the rotating shaft 2 shown in FIG. 8, and is disposed opposite to the rotating body 5 and integrally formed with the nozzle head unit 45. Nozzle heads 45C, 45M, 45Y, 45
K (see FIG. 9), the nozzle heads 45C, 45M, and 45M are applied to the rotating print medium (paper P) wound around the rotating body 5.
45Y and 45K are formed to be printable by printing.

That is, the print medium (paper P) sent from the paper feeding means is fed to the rotating body 5 at a predetermined timing by the feeding means, and is closely contacted with the outer peripheral surface of the rotating body 5 by, for example, electrostatic attraction. It is wound and held. The rotating body 5
It is rotated at a reference rotation speed (for example, 120 RPM) about the axis Z in FIG. 8 and in a predetermined rotation (R) direction.

A nozzle head 45 for each color, which has a large number of ink jet nozzles arranged in the main scanning (X = Z) direction and is displaced in the R direction as shown in FIG.
C, 45M, 45Y, and 45K can be selectively driven, and the selectively driven nozzle heads 45C, 45M,
Printing can be performed while ejecting ink for each color onto the rotating print medium (P) from the respective inkjet nozzles of 45Y and 45K.

In FIG. 9, the nozzle head unit 45
(45C, 45M, 45Y, 45K) is reciprocated in the row (X) direction by a predetermined distance (for example, the pitch between inkjet nozzles) by the reciprocating moving means, and is printed in the row direction on the rotating rotating body 5, that is, the print medium. (Dots D11-
Dn1) and printing in the row (Y = R) direction (dots D11 to D1m,..., Dn1 to Dnm) while utilizing the rotation of the rotating body 5 in the printing (X) direction, for example, during forward movement. . That is, printing in the row (X... Main scanning) direction and printing in the column (Y... Sub-scanning) direction can proceed at the same time.

Further, when each ink jet nozzle is of a variable number of times of ink ejection (multidrop) system or a variable amount of ink ejection amount (volume control) system, each gradation of each pixel (ink dot) is designated. Printing. For example, the yellow ink dot DY can be printed by designating any one of seven gradations.

[0009]

Incidentally, in the case of the above-described proposed printer A, in addition to the normal print mode for printing all dots forming the dot pattern to be printed, for example, in preparation for test printing, high-speed printing or ink consumption is also possible. It is required that a draft mode capable of reducing the amount can be selected. In other words, the printing is performed by thinning out the dots in the main scanning (X) direction or the sub-scanning (Y) direction among all the dots forming the print target dot pattern.

However, the number N of dots constituting a one-line image extending in the main scanning direction is divided by one ink jet or the number N of dots is divided into n equal parts, and all the dots of the one line are rotated by n ink jets. When the draft mode is directly introduced into a color ink jet printer (printer A) that can print on the print medium held in No. 5 and can also specify and print the gradation of each dot D, it is compared with the case of the normal print mode. In the case of thinning out in the main scanning direction, the number of rotations of the rotating body 5 can be reduced by an amount corresponding to the thinning out, so that the printing speed can be surely increased. However, the ink consumption can be certainly reduced (for example, halved).

However, when any of the thinning methods is selected, the roughness of the image quality becomes conspicuous, so that even if the printing speed is increased or the ink consumption is reduced, the value of the printing itself is reduced. There is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a color ink jet printer capable of suppressing the printing quality from being reduced in a draft mode in which dots are thinned out.

[0013]

According to a first aspect of the present invention, there is provided a method for forming a dot pattern to be printed, comprising a plurality of ink jet nozzles arranged in the main scanning direction and forming a one-line image extending in the main scanning direction. It is possible to print all the dots of the one line on a print medium held by a rotating body by dividing the number N of dots by one ink jet or by dividing the number of dots N into n equal parts and by n ink jets. In the color ink jet printer capable of printing by designating the gradation of each, a normal print mode in which all the dots forming the print target dot pattern are printed, and a main scanning direction among all the dots forming the print target dot pattern Alternatively, one dot adjacent in the sub-scanning direction
Draft mode in which printing is thinned out every other is selectively switched and formed so as to be operable, and when the draft mode is selected, each color gradation of each dot to be printed is changed to the corresponding dot of each dot thinned out on one side adjacent to the other side. This is a color inkjet printer that is formed so as to be capable of correcting each gradation.

In this invention, for example, when the number N of dots constituting one line image is equally divided into n (2) and all dots of the one line are printed by n (2) ink jets, normal printing is performed. If you choose the mode,
At the first rotation of the rotator, half of all the dots forming the print target dot pattern are printed, and at the second rotation, the remaining one is printed.
/ 2 is printed. The gradation of each dot is the designated gradation.

When the draft mode is selected, every other dot adjacent to the main scanning direction (or sub-scanning direction) of all the dots forming the dot pattern to be printed in the first rotation of the rotating body is set. Print with thinning. At this time, each color gradation of each dot is corrected in correspondence with each gradation of each dot thinned out on one adjacent side. For example, the tone of a certain dot (for example, “4”) is corrected (corresponding to (added) to the tone of the dot thinned on one side (for example, “2”) to the tone (“6”). I do.

Therefore, when the draft mode is selected and thinning is performed in the main scanning direction, the number of rotations of the rotating body can be reduced by an amount corresponding to the thinning, so that printing can be speeded up. Although the number of rotations is the same, the amount of ink consumption can be reduced (for example, halved), and the roughness of the print image quality can be suppressed regardless of which thinning method is selected, so that the value of printing itself can be improved.

According to a second aspect of the present invention, each color gradation of each dot to be printed when the draft mode is selected,
Corrected to each added color gradation by adding each corrected gradation obtained by multiplying each color gradation of each dot thinned on one side adjacent to each dot to each color gradation of each dot by a setting correction coefficient And a color inkjet printer formed.

In this invention, each color gradation ("4") of each dot to be printed when the draft mode is selected is replaced with each color gradation ("4") of each dot thinned on one side adjacent to the dot. ) Is multiplied by the set correction coefficient (“2”), and the respective corrected gradations (“2”) are added to each added color gradation (“6”). Therefore, in addition to providing the same operation and effect as the case of the first aspect of the present invention, since the setting correction coefficient can be selected and changed as appropriate, the operation according to the actual situation can be performed.

According to a third aspect of the present invention, there are provided a plurality of ink jet nozzles arranged in the main scanning direction to form a dot pattern to be printed and extend in the main scanning direction.
The number N of dots forming a line image can be printed by a single ink jet or the number N of dots divided into n equal parts and all the dots of one line can be printed on a print medium held by a rotating body by the n number of ink jets. In addition, in a color inkjet printer capable of printing by designating the gradation of each dot individually, a normal print mode for printing all the dots forming the print target dot pattern, and a normal print mode for printing all the dots forming the print target dot pattern A draft mode in which printing is performed by thinning out every other dot adjacent in the main scanning direction or the sub-scanning direction is selectively switched so as to be operable, and each color gradation of each dot to be printed when the draft mode is selected. Is a color that can be corrected in accordance with each gradation of each dot thinned on both sides. An ink jet printer.

In this invention, for example, when the number N of dots forming one line image is equally divided into n (2) and all dots of the one line are printed by n (2) inkjets, the normal printing is performed. If you choose the mode,
At the first rotation of the rotator, half of all the dots forming the print target dot pattern are printed, and at the second rotation, the remaining one is printed.
/ 2 is printed. The gradation of each dot is the designated gradation.

When the draft mode is selected, every other dot adjacent to the main scanning direction (or the sub-scanning direction) among all the dots forming the dot pattern to be printed in the first rotation of the rotator is set. Print with thinning. At this time, each color gradation of each dot is corrected in accordance with each gradation of each dot thinned out on both adjacent sides. For example, the gradation of a certain dot (for example, “2”) is obtained by dividing the gradation of the dot (for example, “2”) decimated on the left side and the gradation of the dot (for example, “2”) decimated on the right side. 2 ”) and the sum (“ 4 ”) is added to correct the gradation (“ 6 ”).

Therefore, when the draft mode is selected and thinning is performed in the main scanning direction, the number of rotations of the rotating body can be reduced by an amount corresponding to thinning on both sides, so that printing can be speeded up. Although the number of rotations of the body is the same, the amount of ink consumption can be reduced (for example, halved), and the roughness of the print image quality can be suppressed regardless of which thinning method is selected, so that the value of printing itself can be improved. .

Further, according to the invention of claim 4, each color gradation of each dot to be printed when the draft mode is selected is thinned out on both sides adjacent to each dot to each color gradation of each dot. Each one-sided dot is set to each color gradation and multiplied by one correction coefficient, and the one-sided correction gradation is added to each color gradation of each other-side dot set by the other correction coefficient. And a color inkjet printer formed to correct the color gradation after each addition.

In this invention, each color gradation ("2") of each dot to be printed when the draft mode is selected is the same as that of each one (left) side dot thinned out on both sides adjacent to each dot. The correction coefficient (“1”) is set to the gradation (“6”).
/ 3 ”) multiplied by the one-sided correction gradation (“ 2 ”) and each color gradation (“ 6 ”) of the other (right) dot by the set other-side correction coefficient (“ １ ／ ”). The added color gradation (“5”) obtained by adding the respective other correction gradations (“3”) is corrected to the gradation (“7”) obtained by adding the respective gradations (“2”). You.

Therefore, in addition to providing the same operation and effect as the case of the third aspect of the invention, the setting one correction coefficient and the setting other correction coefficient can be appropriately selected and changed, so that the operation according to the actual situation can be performed. it can.

Further, according to the present invention, each color gradation of each dot to be printed when the draft mode is selected is thinned out on both sides adjacent to each dot to each color gradation of each dot. Each added color gradation obtained by adding each of the corrected gradations obtained by dividing each color sum gradation, which is the sum of each color gradation of each one side dot and each color gradation of each other side dot, by a set integer. And a color ink jet printer formed.

According to this invention, each color gradation ("4") of each dot to be printed when the draft mode is selected is the same as each color gradation of each dot which is thinned out on both sides adjacent to the dot. One (left) side dot for each color gradation ("2")
And the respective color sum gradation (“4”), which is the sum of each color gradation (“2”) of each other (right) side dot, divided by the set integer (“2”), the respective corrected gradations after division. ("2") is corrected to the added color gradation ("6"). Therefore, in addition to providing the same operation and effect as the case of the third aspect of the invention, the set integer can be appropriately selected and changed in addition to the set one correction coefficient and the set other correction coefficient. Operation.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) The present color inkjet printer 1
0 indicates a normal print mode in which all dots D forming a print target dot pattern are printed as shown in FIGS. 1 to 3; , Sub-scanning (Y = R) direction], and selectively prints out a dot mode in which printing is performed by thinning out every other dot adjacent to every other dot. In addition, each dot to be printed when the draft mode is selected is operable. Each color gradation is formed so as to be correctable corresponding to each gradation of each dot thinned out on one adjacent side.

In this embodiment, in the draft mode, a method of printing by thinning out every other dot in the main scanning (X) direction out of all the dots D forming the dot pattern to be printed, and the dot to be printed Of all the dots D forming the pattern, one of a method of printing by thinning out every other dot adjacent in the sub-scanning (Y = R) direction and printing is selectively operable.

The color ink jet printer has a large number of ink jet nozzles arranged in the main scanning (X) direction as in the case of the printer A of the prior proposal (FIGS. 8 and 9). The number N of dots forming a target dot pattern and forming a one-line image extending in the main scanning direction is divided into n (= 2) equal parts, and all dots D of the one line are rotated by n (= 2) inkjets. It is possible to print on the print medium (paper P) held by the body 5 and to print by specifying the gradation of each dot.
The number N of dots forming one line image extending in the main scanning direction may be printable by one inkjet.

Parts common to those of the previously proposed printer A (FIGS. 8 and 9) are denoted by the same reference numerals, and description thereof will be simplified or omitted.

In FIG. 1, an ink jet printer 1
Numeral 0 is formed by the image processing unit 20 and the engine unit 30, and is a data communication line (network ... for example, LAN)
1 constitutes a part of an ink jet printing system that performs print processing of print data transmitted from an external computer 50 in accordance with the print command.

It should be noted that a configuration may be adopted in which print data generated in the own device (20) is printed based on a print command generated in the own device (20).

The image processing unit 20 includes a CPU 21 and a ROM 2
2, including a RAM 23, an image memory 25, an image control unit 24, and an interface (I / F) 26, and can perform multi-gradation printing while driving and controlling the engine unit 30.

The engine unit 30 includes a CPU 31, a ROM 3
2, an input to which a RAM 33, an operation panel (PNL) 34, an image forming control unit 35 (35C, 35M, 35Y, 35K) and various control units (for example, a sheet feeding control unit, a rotation drive control unit, etc.) 37 are connected. It includes an output (I / O) port 36 and forms an image (prints) based on a print command received from the image processing unit 20.

The image forming means 40C, 40M, 4
Each of 0Y and 40K includes a number of ink jet nozzles, a driving unit (driver), and the like arranged in the X direction, and is positioned in the sub-scanning (Y) direction of FIG. It is incorporated in the nozzle head unit 45 of FIG. 8 in a shifted state.

Then, each of the nozzle heads 45C, 45M,
The pitch of the inkjet nozzles 45Y and 45K in the X direction is 1 / n (= 2) of the pitch P corresponding to the resolution (for example, 600 dpi). Each of the ink jet nozzles is of a variable number of times of ink ejection (multi-drop) method, and the ink dots (pixels) D are changed from the highest gradation (7 gradations) to the lowest gradation (1 gradation... Ink ejection can be performed by designating any one of up to 0 gradation.

For example, in a case where the number N of dots forming one line image is equally divided into n (2) and all dots of the one line are printed by n (2) ink jets, the normal print mode is selected. In the case, the first of the rotating body 5
At the rotation, 1/2 of all the dots (D11 to D5n) forming the print target dot pattern shown in FIG.
.. Are printed, and the remaining half, that is, D21 to D2n, D41 to D4n,. The gradation of each of the dots D11 to D5n is a designated gradation.

When the draft mode is selected, the main scanning direction (X) of all the dots (D11 to D5n) forming the dot pattern to be printed in the first rotation of the rotating body 5 is selected.
(Dots), dots are printed every other dot. As shown in FIG. 2B, dots D11 to D1n, D3
1 to D3n, D51 to D5n,.

When thinning out in the main scanning direction, the rotating body 5 only needs to make one rotation. When thinning out in the sub-scanning direction, two rotations are required.

In the case of printing in which the thinning in the main scanning direction is selected in the draft mode, the respective dots D11 to D1n, D3
Each of the color gradations of D1 to D3n, D51 to D5n,... Corresponds to each dot (D21
To D2n, D41 to D4n,...).

In the case of this embodiment, as shown in FIG. 3, for example, the gradation of the dot D31 (for example, C3-M4-
Y5) is replaced with the dot D41 thinned out on one side (right side).
Is corrected to a gradation (C3-M5-Y7) corresponding (added) to the gradation (for example, C0-M1-Y2). Note that C is cyan, M is magenta, and Y is yellow.

Therefore, when the draft mode is selected and thinning is performed in the main scanning (X) direction, the number of rotations of the rotating body 5 can be reduced by an amount corresponding to the thinning, so that printing can be speeded up and thinning is performed in the sub-scanning direction. In this case, the number of rotations of the rotating body 5 is the same, but the ink consumption can be reduced (for example, halved), and the roughness of the print image quality can be suppressed regardless of which thinning method is selected. Can increase value. In addition, it may be constructed so that correction is performed for each dot (D21) thinned out on one side (left side) adjacent to the dot.

(Second Embodiment) In the second embodiment, the basic configuration and functions are the same as those of the first embodiment (FIGS. 1 and 2).
As shown in FIG. 4, each dot to be printed when the draft mode is selected (for example, as shown in FIG. 2).
Each color gradation (C2-M2-Y2) of D31) is converted to each color gradation (C4-M4-Y6) of each dot (D41) thinned on one side (right side) adjacent to each dot (D31). Each of the added color gradations (C4) obtained by adding the respective correction gradations (C2-M2-Y3) multiplied by the set correction coefficient Rd (= １ ／).
-M4-Y5).

Therefore, in addition to providing the same operation and effect as in the first embodiment, the setting correction coefficient Rd can be appropriately selected and changed, so that operation corresponding to the actual situation can be performed. In addition, it may be constructed so that correction is performed for each dot (D21) thinned out on one side (left side) adjacent to the dot.

(Third Embodiment) In the third embodiment, the basic configuration and functions are the same as those of the first embodiment (FIGS. 1 and 2).
As shown in FIG. 5, each color gradation of each dot (D31) is the same as that of each dot (D21, D41) thinned out on both sides (both sides) adjacent to each other. Corrected accordingly.

In FIG. 5, the gradation (for example, C3-M4-Y4) of the dot D31 is thinned on the right side with the gradation (for example, C1-M0-Y1) of the dot D21 thinned on the left side. Of the dot D41 (for example, C0-M
1-Y2) and the sum (C1-M1-Y3) of the gradation (C
3-M4-Y4) added to the gradation (C4-M5-Y7)
To be corrected.

Therefore, when the draft mode is selected and thinning is performed in the main scanning direction, the number of rotations of the rotating body 5 can be reduced by an amount corresponding to both-side thinning, so that high-speed printing can be achieved.
When thinning is performed in the sub-scanning direction, the number of rotations of the rotating body 5 is the same, but the ink consumption can be reduced (for example, halved), and the first thinning method is used regardless of which thinning method is selected.
Since the roughness of the print image quality can be further suppressed as compared with the case of the embodiment, the value of printing itself can be improved.

(Fourth Embodiment) The fourth embodiment has the same basic structure and functions as those of the third embodiment, but further has one (left) side as shown in FIG. The setting one correction coefficient Ld and the other (right) side setting the other correction coefficient Ld can be set to different values. Of course, the left and right may be the same.

In FIG. 6, each color gradation (C4-C4) of each dot (D31) to be printed when the draft mode is selected.
M5-Y4) is one (left) side dot (D2) thinned out on both sides (left and right) adjacent to each dot (D31).
1) multiplied by one set correction coefficient Ld (= 1/3) to each color gradation (C3-M3-Y3), the respective one correction gradation (C3-M3-Y3)
1-M1-Y1) and each color gradation (C4-M4-Y4) of the other (right) side dot (D41).
(= １ ／) multiplied gray scale (C1-M)
1-Y1) and the added color gradation (C2-M2-
Y2) is added to each of the gradations (C4-M5-Y4) for correction. That is, the corrected gradation is (C6-M7-Y
6).

Therefore, in addition to providing the same operation and effect as in the third embodiment, the setting one correction coefficient Ld and the setting other correction coefficient Rd can be appropriately selected and changed. Can be operated.

(Fifth Embodiment) The fifth embodiment has the same basic configuration as that of the third embodiment, but further selects a draft mode as shown in FIG. In this case, each color gradation (C1-M1-Y1) of each dot (D31) printed on each side (left and right) of each dot (D31) is decimated on both sides (left and right) adjacent to each dot (D31). D21) and each color gradation (C2-M2-Y) of the other (right) side dot (D41).
2) and the respective corrected gradations (C2-M2-Y2) obtained by dividing each color sum gradation (C4-M4-Y4) by the set integer Nd (= 2). C1-M1-Y
1) Each added color gradation after each addition Color gradation (C3-M3-Y)
Corrected to 3).

Therefore, the set integer can be selected and changed as appropriate, so that the operation can be more responsive to the actual situation.

[0054]

According to the first aspect of the present invention, a normal print mode in which all dots are printed, and a draft mode in which all adjacent dots in the main scanning direction or sub-scanning direction are thinned out and printed. And a color ink-jet printer formed so as to be capable of selection switching operation and capable of correcting each color gradation of each dot printed in the draft mode in correspondence with each gradation of each dot thinned out on one adjacent side. Therefore, when the draft mode is selected and thinning is performed in the main scanning direction, the number of rotations of the rotating body can be reduced by an amount corresponding to the thinning, so that printing can be speeded up. Although the numbers are the same, the ink consumption can be reduced (for example, halved), and the roughness of the print quality can be suppressed regardless of which thinning method is selected. It can improve the value of the printing itself.

Further, according to the second aspect of the present invention, when the draft mode is selected, each color gradation of each dot to be printed is thinned out on one side adjacent to each dot to each color gradation of each dot. The same effect as that of the invention according to claim 1 can be obtained because the added color gradation obtained by multiplying each color gradation of each dot by the set correction coefficient and adding each correction gradation can be corrected. In addition to the above, the setting correction coefficient can be appropriately selected and changed, so that operation corresponding to the actual situation can be performed.

According to the third aspect of the present invention, a normal print mode in which all dots are printed, and a draft mode in which all adjacent dots in the main scanning direction or the sub-scanning direction are thinned out and printed. Is formed so as to be capable of selection switching operation, and is formed so as to be able to correct each color gradation of each dot to be printed when the draft mode is selected, in correspondence with each gradation of each dot thinned out on both adjacent sides. Since the printer is a color inkjet printer, if the draft mode is selected and thinning is performed in the main scanning direction, the number of rotations of the rotating body can be reduced by an amount equivalent to thinning on both sides, so that printing speed can be increased, and thinning in the sub-scanning direction can be achieved. In this case, the rotation speed of the rotating body is the same, but the ink consumption is reduced (for example, halved).
In addition to the above, it is possible to suppress the roughness of the print image quality regardless of which thinning method is selected, so that the value of printing itself can be improved.

Further, according to the fourth aspect of the present invention, when the draft mode is selected, each color gradation of each dot to be printed is thinned out on both sides adjacent to each dot to each color gradation of each dot. The one-sided correction sub-gradation obtained by multiplying each color gradation of each one-side dot by one set correction coefficient and the respective one-side correction sub-gradation obtained by multiplying each color gradation of each other-side dot by the other set correction coefficient. Since it is possible to correct the added color gradation after addition, the same effect as in the invention of claim 3 can be obtained, and further, the setting one correction coefficient and the setting other correction coefficient are appropriately selected and changed. It can be operated according to the actual situation.

Further, according to the fifth aspect of the present invention, when the draft mode is selected, each color gradation of each dot to be printed is thinned out on both sides adjacent to each dot to each color gradation of each dot. Each of the added color scales obtained by adding each of the corrected gradations obtained by dividing each of the divided color sum gradations, which are the sum of each color gradation of each one-side dot and each color gradation of each other dot, by a set integer. Since the tone can be corrected, the same effect as in the case of the third aspect of the invention can be obtained, and further, the setting integer can be selected and changed in addition to the setting one correction coefficient and the setting other correction coefficient. , And can be operated according to the actual situation.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a normal print mode and a draft mode.

FIG. 3 is a diagram for explaining an example of a gradation correction printing mode.

FIG. 4 is a diagram for explaining an example of a gradation correction printing mode according to a second embodiment of the present invention.

FIG. 5 is a diagram for explaining an example of a gradation correction printing mode according to a third embodiment of the present invention.

FIG. 6 is a diagram for explaining an example of a gradation correction printing mode according to a fourth embodiment of the present invention.

FIG. 7 is a diagram for explaining an example of a gradation correction printing mode according to a fifth embodiment of the present invention.

FIG. 8 is a schematic side view for explaining a previously proposed color inkjet printer.

FIG. 9 is a diagram for explaining a printing operation.

[Explanation of symbols]

Reference Signs List 5 rotator 10 color inkjet printer 20 image processing unit 30 engine unit 31 CPU 32 ROM 35 image formation control unit 40 image forming means 45 nozzle head unit 45C, 45M, 45Y, 45K inkjet nozzle R rotation direction of rotator X main scanning direction Y Sub-scanning direction D Ink dot P Paper (print medium)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA02 EA11 EC71 EC74 EC80 EE03 2C057 AF05 AF39 AN05 AN06 CA05 CA10 5C077 LL19 MP08 PP33 PP37 PP38 PQ08 PQ12 PQ22 RR18 TT05 5C079 KA12 LA28 LA31 LB01 MA03 NA02 NA03

Claims (5)

[Claims] An ink jet nozzle having a plurality of ink jet nozzles arranged in the main scanning direction and forming a dot pattern to be printed and forming a one-line image extending in the main scanning direction by one ink jet. Alternatively, the number of dots N is divided into n equal parts, and the first
In a color inkjet printer capable of printing all dots of a line on a print medium held by a rotating body and printing by specifying the gradation of each dot individually, printing all the dots forming the dot pattern to be printed And a draft mode in which, among all the dots forming the print target dot pattern, dots that are adjacent to each other in the main scanning direction or the sub-scanning direction are thinned out and printed. In addition, a color inkjet printer is formed so as to be able to correct each color gradation of each dot to be printed when the draft mode is selected, in correspondence with each gradation of each dot thinned out on one adjacent side. 2. The method of changing each color gradation of each dot printed when the draft mode is selected to each color gradation of each dot thinned on one side adjacent to each dot. 2. The color ink jet printer according to claim 1, wherein the color ink jet printer is configured to correct the color gradation after addition by adding the respective correction gradations multiplied by the set correction coefficient. 3. A method of forming a dot pattern to be printed, comprising a plurality of ink jet nozzles arranged in the main scanning direction, and the number N of dots forming a one-line image extending in the main scanning direction is determined by one ink jet. Alternatively, the number of dots N is divided into n equal parts, and the first
In a color inkjet printer capable of printing all dots of a line on a print medium held by a rotating body and printing by specifying the gradation of each dot individually, printing all the dots forming the dot pattern to be printed And a draft mode in which, among all the dots forming the print target dot pattern, dots that are adjacent to each other in the main scanning direction or the sub-scanning direction are thinned out and printed. And a color ink jet printer formed so as to be able to correct each color gradation of each dot to be printed when the draft mode is selected, in correspondence with each gradation of each dot thinned out on both adjacent sides. 4. The color gradation of each dot to be printed when the draft mode is selected is replaced by the color gradation of each one-side dot thinned on both sides adjacent to the dot to the color gradation of the dot. Each of the added color gradations obtained by adding the respective one-correction gradation obtained by multiplying the correction coefficient by one correction coefficient and the respective other correction gradation obtained by multiplying each color gradation of the other-side dot by the other correction coefficient The color ink jet printer according to claim 3, wherein the color ink jet printer is configured to correct the color ink jet. 5. The color gradation of each dot to be printed when the draft mode is selected, the color gradation of each one-side dot thinned on both sides adjacent to the dot to the color gradation of the dot. And the respective corrected color gradations obtained by adding the respective corrected sum gradations obtained by dividing the respective color sum gradations which are the sums of the respective color gradations of the respective other side dots by the set integer. The color inkjet printer according to claim 3, wherein