JPH0725036A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To independently conduct monochromatic printing and color printing and to print at a high speed in the case of the monochromatic printing. CONSTITUTION:Number of nozzles of a black ink print head 1K is 2N, number of nozzles of color ink print heads 1C, 1M, 1Y are N, and placed in a carriage 2. In the case of color printing, the head 1K is used only at a half nozzle from above. In the case of first scanning, a printing area 6K is printed to be recorded by the head 1K. A recording sheet 4 is conveyed by a print recording width D. In the case of second scanning, a new printing area is printed by the black head. Simultaneously, a printing area 6KCMY is printed to be recorded by three color ink print heads to be superposed on the first scanning printing. The monochromatic printing is conducted by 2N of nozzles of the head 1K.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus capable of full color printing and single color printing.

[0002]

2. Description of the Related Art In an inkjet recording apparatus capable of full-color printing and single-color printing, a method of printing by arranging a single-color black ink print head and a plurality of color-ink print heads in parallel to the scanning direction of the print head ,
Alternatively, a method of arranging the print head in a direction perpendicular to the scanning direction is known, but in both cases, the nozzle of the black ink print head and the nozzle of the color ink print head are
They are arranged in parallel so as to be parallel to the direction perpendicular to the main scanning direction of printing.

By the way, in such a conventional technique, the black ink print head and the other color ink print heads arranged in parallel have a
Since printing is performed continuously on the same area of the recording paper, there is almost no time difference between the printing of each color when looking at the same printing portion of the recording paper, and the ink on the recording paper printed by one print head The next print head prints before it penetrates the paper, causing interference between inks,
There is a problem that an image quality defect called color blur occurs.

In an ink jet recording apparatus capable of full-color printing and single-color printing, the black ink print head and the color ink print head have the same number of nozzles and have the same performance, so that single-color printing is performed. In this case, the printing speed is the same as the printing speed when full-color printing is performed, and there is also a problem that the printing speed cannot be increased.

[0005]

SUMMARY OF THE INVENTION Therefore, the inventors of the present invention can independently perform monochromatic printing and full-color printing, and have a high printing speed difference and a high printing speed between inks when color overprinting is performed. As a result of earnest research on realization, it is possible to perform single-color printing and full-color printing independently, high-density or high-speed printing is possible during single-color printing, and there is a sufficient time difference between inks during full-color printing. The present invention has been accomplished by finding out an inkjet recording device that can do this.

Therefore, the present invention is an ink jet recording apparatus capable of independently performing monochromatic printing and full color printing, but when performing monochromatic printing, an ink jet recording apparatus capable of high density printing or high speed printing. It is intended to provide.

[0007]

According to a first aspect of the present invention, in an ink jet recording apparatus having a single color ink print head and a plurality of color ink print heads, the number of nozzles of the single color ink print head is changed. The feature is that the number of nozzles of the color ink print head is larger than that of the color ink print head.

According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the number of nozzles of the single color ink print head is at least twice the number of nozzles of the color ink print head. According to a third aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the single-color ink print head is arranged such that the nozzle protrudes toward the paper supply side from the color ink print head. It is characterized by that.

According to a fourth aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the second aspect, or the third aspect, the nozzle of the single-color ink print head has a nozzle projecting toward the paper supply side more than the color ink print head. It is characterized by being arranged.

According to a fifth aspect of the present invention, in the ink jet recording apparatus according to the fourth aspect, the amount of protrusion of the nozzle of the single color ink print head is the same as that of the color ink print head. In the invention according to claim 6, in the inkjet recording device according to claim 5, the print information sent to the inkjet recording device is monochrome printing. When it is information, printing is executed by all the nozzles of the single color ink print head, and when the information sent is color information, the nozzles of the black ink head are printed only by the nozzles corresponding to the parts protruding from the color ink print head. It is characterized by executing.

According to a seventh aspect of the present invention, in the ink jet recording apparatus according to the fourth aspect, the protrusion amount of the nozzle of the single color ink print head is the print recording width of the color ink print head and each color ink print. It is characterized in that it corresponds to the sum of the widths of the non-ink jetting areas provided between the heads.

In an eighth aspect of the present invention, in an ink jet recording apparatus capable of independently performing monochromatic ink print recording and color ink print recording, the print recording width in one scan of the head when monochromatic ink print recording is performed. The ink jet recording apparatus according to claim 8 is characterized in that it is not less than the sum of the print recording widths in one scan of the head when performing print recording for each color ink. In the above, the print recording width at the time of single-color ink print recording is an integral multiple of the print recording width by one head at the time of color ink print recording.

[0013]

According to the present invention, at least one print head among the plurality of print heads that have been installed in parallel so far is arranged in a staggered manner so that the print areas are different from each other, so that printing is performed in ink color superposition. Since a time difference can be provided and the previously printed ink can sufficiently penetrate into the recording paper, it is possible to prevent ink color bleeding, which has been a problem as an image quality defect.

Further, when a single-color ink print head, for example, a black ink print head has a larger number of nozzles than the nozzles of other color ink print heads, black ink, which is frequently used, is printed in a single color. In addition, it is possible to improve the print recording speed.

Further, by arranging the print recording areas of the adjacent print heads at the shifted positions, it is possible to prevent ink color bleeding which causes a print time difference and causes an image quality defect. Further, in the case of performing full color printing. In addition, since printing can be performed without changing the ink color superposition order in the reciprocating direction of the print head scanning, high-speed print recording can be performed.

[0016]

FIG. 1 is an explanatory diagram of a first embodiment of an ink jet recording apparatus of the present invention, showing a configuration diagram when a head is mounted on a carriage and a state of a printing operation during full color printing. . In the figure, 1K is a black ink print head, 1C is a cyan ink print head, 1M is a magenta ink print head, 1Y is a yellow ink print head,
2 is a carriage, 3 is a print head scanning direction, 4 is a recording paper, 5 is a paper conveyance direction, 6K is a black ink print area, 6KCMY is a black ink, cyan ink, magenta ink, and yellow ink overlapping print area, and the first is
The print sample of the second scan is a print sample of the second scan.

The construction of the print head of this embodiment is the black ink print head 1K having 2N nozzles, and the first
Color ink print head 1 with a nozzle number N of 1/2
C, 1M and 1Y are mounted on the carriage 2 in parallel so as to be perpendicular to the print head scanning direction 3. Also, the black ink printing are arranged in the head 1K to the 2N-th nozzle 1K _2N and the color ink print head are N-th nozzle 1C _N, 1M _N, are arranged so as adjacent the 1Y _N.

Here, the print recording width by one scan of the print head will be described with reference to the schematic view shown in FIG. In the figure, 1 is the printing head 1 ₁ to 1 _N nozzles, 3 print head scanning direction, the recording sheet 4, 7 print pixel, D is printed recording width,
d is the distance between the centers of adjacent nozzles. The print pixels 7 printed and recorded by the N ink droplets ejected from the _N nozzles 1 ₁ to 1 _N are arranged in series on the recording paper 4, and the print recording width D is N × d.

A color printing method in the first embodiment will be described. The print information sent to the print head is
When it is necessary to perform color printing using two or more colors of ink including black ink, the number of nozzles N of the black ink print head is only 1/2 from the paper feed side (upper side of the drawing). used. Print head 1
The print recording width D by scanning is the print recording width 2 that can be printed by the number of nozzles 2N of the black ink print head 1K.
1/2 of D, that is, three color ink print heads 1
The width is the same as the print recording width D of C, 1M and 1Y.

When printing is performed by this head configuration, in the first scan, as shown in the print sample, only the black ink is printed from the black ink print head 1K, and the black ink print area 6K is printed and recorded. Is performed. After that, the recording paper 4 is printed with the recording width D
Carry only the length equivalent to.

In the next second scan, print recording is performed by the black ink print head 1K in a new print area. At the same time, ink ejection from the three color ink print heads of the cyan ink print head 1C, the magenta ink print head 1M, and the yellow ink print head 1Y
In the black ink print area 6K which has already been printed and recorded in (1), the black ink, the cyan ink, the magenta ink and the yellow ink are printed and recorded in the overlapping print area 6KCMY as shown in the print sample.

In this way, the printing and recording are sequentially carried out. However, since there is a time difference corresponding to one scan of the print head from the printing of the black ink to the printing of the next color ink, the black printing is carried out. The next ink can be printed after the penetration of the ink into the recording paper is completed. Therefore, even when a black ink having poor penetrability is used, it is possible to prevent the image quality defect such as the color bleeding of the ink, which has occurred between the black ink and the color ink, which has occurred so far. It was

When the print information is black-and-white information, the black ink print head 1K ejects ink from all the nozzles having a nozzle number of 2N. The recording paper 4 is conveyed by the print recording width 2D in which printing is performed in one scan of the black ink head 1K. In addition, the type of recording paper installed in the paper discharge mechanism of the recording device is identified,
Depending on the type of paper, black ink print head 1
It is determined whether the printing with K is performed only during one-direction scanning in the scanning direction or during both-direction scanning. In addition, whether to perform one-way printing or two-way printing can be selected by the user through the control panel of the recording apparatus.

Printing with the black ink print head
The print recording width of one scan of the print head is doubled when the color print recording is performed by a plurality of print heads accompanied by the color ink print head and when the single color print recording is performed only by the black ink print head. Therefore, the recording speed is doubled and high-speed printing becomes possible. Further, when the used paper is a recording paper to which the reciprocal printing is applied, or when the user selects the reciprocal printing, the print recording can be further performed at the double printing speed.

FIG. 2 is an explanatory view of the second embodiment of the ink jet recording apparatus of the present invention, and is a configuration diagram when the print head is mounted on the carriage. In the figure, the same parts as those in FIG. In this embodiment, two print heads can be used to perform monochromatic print recording and color print recording. One of the print heads has a nozzle number of 3N and is a two-color integrated print head in which the nozzle number is divided into a nozzle number N and a nozzle number 2N. In this print head, the print head in which the number of nozzles was divided into 2N was a black ink print head 1K, and the subsequent print head was a magenta ink print head 1M. The other print head is a two-color integrated print head in which the number of nozzles is 2N and the number of nozzles is equally divided into two. The print heads were a cyan ink print head 1C and a yellow ink print head 1Y. The black ink print head 1K is arranged on the paper supply side that is close to the paper transport mechanism side. Further, the cyan ink print head 1C is arranged on the paper supply side in parallel with the black ink print head 1K. The magenta ink print head 1M is arranged in series with the black ink print head 1K on the paper discharge side, which is integrally formed. The yellow ink print head 1Y is arranged in series with the cyan ink print head 1C on the paper discharge side which is integrally formed. Therefore, in this embodiment, the order of printing colors is black ink, cyan ink, magenta ink, and yellow ink.

According to this structure, the recording paper is supplied,
When printing is started, in the first head scan, black ink print recording is performed in the print area corresponding to the print recording width D by half the number of nozzles on the paper supply side of the black ink print head 1K. Be done.

In the second head scan, the print recording width D
After the recording paper is conveyed by a length corresponding to, the print area is printed by a nozzle of 1/2 of the black ink print head 1K in a new print area, and the print area in which the black ink printed by the previous head scan is printed. Then, the print recording is performed by the cyan ink print head 1C overlaid on the black ink.

After the third head scan, the recording paper is conveyed and supplied for each print recording width D, and the black ink print head 1K prints and records the black ink on a new print area. Print recording is performed by the cyan ink print head 1C in the area, and print recording is performed by the magenta ink print head 1M and the yellow ink print head 1Y in the area where the cyan ink is overprinted on the black ink by the immediately preceding head scan. Be done. This process is repeated to perform full-color print recording.

In the first embodiment, since the four print heads are arranged in parallel, the lateral width of the carriage in the printing apparatus is large, and the width in the head scanning direction of the printing apparatus is correspondingly large. In the second embodiment, by arranging the two-division heads in parallel and arranging as described above, the size of the width of the carriage becomes about half that of the first embodiment, and the recording apparatus can be downsized. Become. Further, since there is a time difference for one scan of the head between the printing of the black ink, the printing of the cyan ink, and the printing of the magenta ink and the yellow ink, until the ink penetrates into the recording paper. Since it is possible to have sufficient time, it is possible to prevent image bleeding such as ink color bleeding, even in inks with slow penetrability. In the case of black printing, high-speed printing can be performed as in the first embodiment.

FIG. 3 is an explanatory view of the third embodiment of the ink jet recording apparatus of the present invention, and is a configuration diagram when the print head is mounted on the carriage. In the figure, the same parts as those in FIG. In this embodiment, it is possible to perform monochromatic print recording and color print recording by using three print heads. The width of the carriage can be made smaller than that of the first embodiment, and the height of the carriage can be made smaller than that of the second embodiment.

Also in this embodiment, the ink is frequently used in the ink jet recording apparatus, and it is suitable especially when a large amount of one color is printed. In the figure, the black ink is used for a large amount of printing. The layout of the print head in one case is shown. The number 2N of nozzles of the black ink print head 1K is twice the number N of nozzles provided in the color ink print head. When printing is performed only with black ink, the total number of nozzles 2N is used for printing, and when full-color printing is performed, the number of nozzles of black ink print head 1K is 2N.
Only half of the nozzles are used for jetting and the rest are stopped. Therefore, similarly to the second embodiment, the black ink, which is frequently printed, can be printed at about twice the normal printing speed, and only the black ink print head can be driven. It is also possible to print back and forth by not restricting the order of color superposition when it is being performed.
Can be faster.

The structure of the print head for color printing is as follows.
A two-color integrated printhead with 2N nozzles and a one-color printhead with N nozzles are black ink printheads 1K
Used with. The print head with 2N nozzles
This was divided into two parts to form a cyan ink print head 1C and a magenta ink print head 1M. The print head having N nozzles was the yellow ink print head 1Y. The black ink print head 1K is arranged close to the paper transport mechanism side. Cyan ink print head 1
C is arranged in parallel with the black ink print head 1K on the paper supply side, and the magenta ink print head 1M is arranged in series on the paper discharge side. The yellow ink print head 1Y is arranged adjacent to the magenta ink print head 1M. In this embodiment as well, the color overlapping order of printing is
Although the order of the black ink, the cyan ink, the magenta ink, and the yellow ink is set, another color superposition order can be realized depending on the head arrangement.

According to this structure, the recording paper is supplied,
When printing is started, in the first head scan, black ink print recording is performed in the print area corresponding to the print recording width D by half the number of nozzles on the paper supply side of the black ink print head 1K. And over this,
Print recording is performed by the cyan ink print head 1C.

After the second head scan, the recording paper is fed and supplied for each print recording width D, and the print recording by the black ink print head 1K and the cyan ink print head are superimposed on the print recording in the new print area. Printing and recording by 1C is performed. Further, by the immediately preceding head scan, print recording by the magenta ink print head 1M and the yellow ink print head 1Y is performed in the area where the cyan ink is overprinted on the black ink. This process is repeated to perform full-color print recording.

FIG. 4 is an explanatory view of a fourth embodiment of the ink jet recording apparatus of the present invention, showing the configuration when the head is mounted on the carriage and the printing operation during black ink single color printing and full color printing. It shows the situation. In the figure, the same parts as those in FIG. 6KC is an overlapping print area of black ink and cyan ink, 6KCM is an overlapping print area of black ink, cyan ink and magenta ink, is a print sample of the third scan, and is a print sample of the fourth scan. In this embodiment, two print heads are used to perform monochromatic print recording and color print recording.

In this embodiment, a three-color integrated color ink print head and a black ink print head are arranged in parallel. In the color ink print head, one print head in which the nozzles are arranged on a straight line is divided into three equal parts and the same number N of nozzles is used.
It is composed of color ink print heads 1C, 1M and 1Y. The black ink print head 1K has 4N nozzles, which is four times the number N of color ink print heads.
And is arranged so as to project toward the print paper feed side by a length corresponding to the print recording width of one color ink print head, rather than the three-color integrated color ink print head. The three-color integrated color ink print head and the black ink print head are mounted on the carriage 2 and reciprocally scan in a direction perpendicular to the nozzle arrangement direction.

When full-color printing is performed, FIG.
As shown in (B), the print start tip on the recording paper is p
The print head is scanned in the direction perpendicular to the paper transport direction 5. In the first head scan, the black ink print head 1K prints on the black ink print area 6K shown in the print sample by the nozzles corresponding to N nozzles from the leading end on the side where the recording paper is fed. Is performed.

Next, the recording paper is conveyed by the print recording width D printed by N nozzles of the black ink print head 1K, and the print start front end on the recording paper stops at the position q. . In the second head scan, as shown in the print sample, the new print area becomes the black ink print area 6K, and print recording is performed by the black ink print head 1K. At the same time, the black ink printing area that has advanced to the position of q becomes the overlapping printing area 6KC of the black ink and the cyan ink, and the cyan ink that is the first color ink print head is arranged on the black ink that has already been printed and recorded. The print records from the ink print head 1C are overlaid.

Similarly, the third head scan is performed while the recording paper has advanced to the position r due to the conveyance of the print recording width D of the recording paper. In this head scan, as shown in the print sample, the new print area becomes the black ink print area 6K, and print recording is performed by the black ink print head 1K. At the same time, the black ink print area that has advanced to the position of q becomes the overlapping print area 6KC of black ink and cyan ink, and the print recording from the cyan ink print head 1C is overlaid on the black ink that has already been printed and recorded. Furthermore, r
The black ink / cyan ink print area that has advanced to the position becomes the overlapping print area 6KCM of the black ink, cyan ink, and magenta ink, and the print from the magenta print head 1M is performed on the already recorded black ink and cyan ink. Records are overlaid.

Further, the recording paper is conveyed, and the fourth head scanning is carried out while the recording paper has reached the position s. In this head scan, as shown in the print sample, the new print area becomes the black ink print area 6K, and print recording is performed by the black ink print head 1K. At the same time, the black ink print area that has advanced to the position of q becomes the overlapping print area 6KC of black ink and cyan ink, and the print recording from the cyan ink print head 1C is overlaid on the black ink that has already been printed and recorded. Further, the black ink / cyan ink print area that has advanced to the position of r becomes the overlapping print area 6KCM of the black ink, cyan ink, and magenta ink, and the magenta print head 1M is printed on the black ink and cyan ink already printed and recorded. The print records from are overlaid. Further, the black ink, cyan ink, and magenta ink printing areas that have advanced to the position of s become the overlapping printing area 6KCMY of the black ink, cyan ink, magenta ink, and yellow ink, and the black ink, cyan ink, and magenta that have already been printed and recorded. The print record from the yellow print head 1Y is superposed on the ink.

After that, as shown in the print sample of,
Print recording by each print head is performed simultaneously. At the end of the recording paper, from the time when the black ink ejecting nozzle reaches the end position, the black ink print head 1K sequentially finishes printing and recording, and the print recording width of the yellow ink ejecting nozzle reaches the end of the paper. When the printing is performed, printing on the entire surface of the recording paper is completed, and the printed paper is ejected to the outside of the machine.

Further, when the color superposition order for full-color printing is black ink, cyan ink, magenta ink, and yellow ink, the carriage on which the head is mounted is scanned over the paper from the initial predetermined position. Since the order of color superimposition performed when the carriage is scanned from the position on the opposite side and returning to the initial position can be the same, the same as when performing one-way printing. Color reproduction can also be performed by reciprocal scanning printing.

Further, according to the printing process using this head structure, since the recording sheets are overlaid each time they are conveyed by the amount corresponding to the print recording width, even when ink or paper having poor permeability is used, It is possible to give a sufficient time difference for one scan of the head until the next ink is overprinted, and it is possible to prevent image bleeding such as ink bleeding that has occurred during color overwriting. Since the time difference can be made the same, the color tone can be made the same for each print recording width, and the print quality can be made the same.

Further, since the reciprocal print recording is possible, even in the case of color printing, the print recording speed can be doubled as compared with the first to third embodiments, and high speed printing can be performed. Recording is now possible. In the case of reciprocal printing, it is of course necessary to change the timing of data supplied to the black ink print head and the color ink print head between the forward and backward passes.

Further, in this head configuration, ink is initially supplied even when the order of ink color superimposition is different from the order described above, such as black ink, yellow ink, magenta ink, and cyan ink. The object can be achieved only by changing the position of the ink to be filled in the ink tank portion, and the print head can be configured without restricting the order of color ink color overlapping.

Further, as shown in FIG. 4A, only a black ink print head, which is frequently used, is used for a single color,
When performing print recording, the number of nozzles that eject ink is set to 4N. Therefore, the print recording width can be made four times as large as when full-color printing is performed,
At this time, the paper is also conveyed by a feed width four times as wide as when full-color printing is performed, so the print recording speed is
It is four times the recording speed when one-way printing of full color printing is performed. Further, when reciprocal printing is performed, the recording speed is improved by about 8 times the recording speed when full-color printing in one direction is performed.

FIG. 7 is a perspective view of a specific example of the head structure in the fourth embodiment. In the figure, 1K is a black ink print head, 1CMY is a color ink print head of three-color integrated type of cyan ink, magenta ink, and yellow ink, 7 is an ink ejection nozzle, and 8 is a heat dissipation plate. As described above, the color ink print head 1CMY
Is, as shown in FIG. 4, three color print heads 1C, 1M,
It is used by dividing it into 1Y. The heat dissipation plate 8 does not necessarily have to be provided.

FIG. 5 is an explanatory view of a fifth embodiment of the ink jet recording apparatus of the present invention, showing a configuration diagram when a head is mounted on a carriage and a state of a printing operation during full color printing. In the figure, the same parts as those in FIG. In this embodiment also, two print heads are used to perform monochromatic print recording and color print recording.

In this embodiment, two heads having 3N nozzles are used perpendicularly to the head scanning direction. Further, one of the two heads was a black ink print head, and this head was arranged on the paper feed side with a shift corresponding to the number N of nozzles. The other of the two heads was a three-color integrated color ink print head, which was arranged in parallel with the black ink print head. The color ink print head is composed of three color ink print heads 1C, 1M and 1Y having the same number of nozzles N, which is obtained by dividing one print head having nozzles arranged in a straight line into three equal parts. Therefore, the black ink print head 1K has three times the number N of nozzles of the color ink print head. The color overlay order for full-color printing is black ink,
When the cyan ink, the magenta ink, and the yellow ink are arranged in this order, the color ink print head with the three-color integrated structure is
From the paper feeding side, cyan ink print head 1C, magenta ink print head 1M, yellow ink print head 1
It becomes the arrangement of Y.

As described above, in this embodiment, since the black ink print head and the color ink print head of three colors integrated have the same number of nozzles, it is possible to form the ink jet nozzle by the same manufacturing process.

Printing conditions of full-color printing are shown in print samples (1) to (4). Also in this print sample, the order of color superimposition at the time of full-color printing was black ink, cyan ink, magenta ink, and yellow ink. Therefore, the printing state is the same as that of the fourth embodiment described in FIG. 4B. Since they are the same, detailed description thereof will be omitted.

When the color superposition order for full-color printing is black ink, cyan ink, magenta ink, and yellow ink, the carriage on which the head is mounted is scanned over the paper from the initial predetermined position. Since the order of color superimposition performed when the carriage is scanned from the position on the opposite side and returning to the initial position can be the same, the same as when performing one-way printing. Color reproduction can also be performed by reciprocal scanning printing.

Further, also in this embodiment, since the recording sheets are overlaid each time they are conveyed by the amount corresponding to the print recording width, even if the ink having poor permeability or the sheet is used, the next ink It is possible to give a sufficient time difference for one scan of the head until
It is possible to prevent the image quality defect such as ink bleeding that occurred at the time of color superposition, and since the time difference until color superposition can be made the same, it is possible to make the hue of each print recording width the same. There is an advantage that the quality can be the same.

Further, since the reciprocal print recording is enabled, the print recording speed can be doubled as compared with the first to third embodiments even in the case of color printing, and high speed printing can be performed. Recording is now possible. In the case of reciprocal printing, it is of course necessary to change the timing of data supplied to the black ink print head and the color ink print head between the forward and backward passes.

Further, in this head structure, ink is initially supplied even when the order of color superposition of inks is different from the order described above, such as black ink, yellow ink, magenta ink, and cyan ink. The object can be achieved only by changing the position of the ink to be filled in the ink tank portion, and the print head can be configured without restricting the order of color ink color overlapping.

With this head structure, when only the black ink print head, which is frequently used, is used for a single color and print recording is performed, the number of nozzles for ejecting ink is 3N.
Use as individual pieces. Therefore, the print recording width can be tripled when full color printing is performed, and at this time, the paper is also transported by a feed width that is three times as wide as when full color printing is performed. , 3 times the recording speed when full-color printing is performed in one direction. Further, when reciprocal printing is performed, the recording speed is improved by about 6 times the recording speed when full-color printing in one direction is performed.

FIG. 8 is a perspective view of a specific example of the head structure in the fifth embodiment. 7, those parts that are the same as those corresponding parts in FIG. 7 are designated by the same reference numerals, and a description thereof will be omitted. As mentioned above,
As shown in FIG. 5, the color ink print head 1CMY is divided into three color print heads 1C, 1M and 1Y for use. The heat dissipation plate 8 does not necessarily have to be provided.

FIG. 6 is an explanatory diagram of a sixth embodiment of the ink jet recording apparatus of the present invention, showing a configuration diagram when a head is mounted on a carriage and a state of a printing operation during full color printing. In the figure, the same parts as those in FIG. Reference numeral 9 is a non-ink jetting area. In this embodiment, two print heads are used to perform monochromatic print recording and color print recording.

In this embodiment, a plurality of color ink print heads having N nozzles, for example, three print heads are arranged on a straight line perpendicular to the scanning direction. A non-ink jetting area 9 is provided between the color ink print heads 1C, 1M and 1Y. The non-ink jetting region 9 can be formed by using the three-color integrated type color print head as a dummy nozzle that does not use the nozzles at the boundaries of the three colors for ink jetting. Further, the color print heads configured separately are connected and arranged, and the non-ink jetting area 9 is formed by the areas on both ends where the nozzles are not formed.
Can also be formed. You may interpose a suitable spacer.

In the ink jet print head, it is feared that the surface of the ink may be stained with the ink by ejecting the ink to deteriorate the image quality. If necessary, the dirt is removed by a method of cleaning with a wiper member. However, in the above-described integrated print head or a print head in which a plurality of print heads are connected to each other and the nozzle surface is connected, the ink adhering to the surface may be mixed with color, or the cleaning operation may be different. Color mixing is accelerated by the wiper member, resulting in deterioration of image quality. As a countermeasure, a cleaning method using a wiper member having a new structure has been considered, but it has not been possible to prevent ink color mixing.

Therefore, in such a print head,
It is advisable to provide the non-ink-jetting region 9 by disposing nozzles that are not used for ink-jetting between the heads of the respective colors, or by forming regions having no nozzles. As a result, it is possible to prevent color mixture of ink due to dirt on the head surface at the time of ink ejection or color mixture at the time of cleaning operation by the wiper member, and prevent deterioration of image quality.

As for the arrangement of the print heads, the black ink print head 1K is arranged in parallel with the three-color integrated color ink print heads 1C, 1M and 1Y and on the side of the paper transport mechanism. Three-color integrated color ink print head 1
The number of nozzles of C, 1M, and 1Y is N, and the print recording width is a. In addition, the adjacent print heads 1C,
The width of the non-ink jetting region 9 between 1M and 1Y is b.
The nozzles provided on the black ink print head 1K are
From the leading edge of the cyan ink print head 1C on the paper feed side (a
+ B) is arranged so as to project toward the paper feed side. The width D by which the paper is conveyed needs to be a or less, but in one example, D and a are made equal. Further, if the print recording width of the black ink print head is 5D, that is, the number of nozzles is 5N, and thus the width of the non-ink jetting region 9 is D / 3, 5D paper conveyance, that is, 5 times. The same print state can be repeated by scanning the head. FIG. 6 illustrates a printing state in the print head designed under these conditions. However, the condition is not limited to this, and the width D in which the paper is conveyed is
However, if a is less than or equal to a, it is possible to perform continuous printing in the paper transport direction. The value of b may be appropriate. However,
It is preferable to be an integral multiple of the nozzle interval.

When full-color printing is performed, the print start front end on the recording paper is conveyed to the position p, and the print head is scanned in the direction perpendicular to the paper conveyance direction 5. In the first head scanning, the black ink having the print recording width shown in the print sample is D by the nozzles corresponding to N nozzles from the leading end of the black ink print head 1K on the side where the recording paper is fed. Print recording is performed in the print area 6K.

Next, the recording paper is conveyed by the print recording width D printed by N nozzles of the black ink print head 1K, and the print start front end on the recording paper stops at the position q. . In the second head scan, as shown in the print sample, the new print area becomes the black ink print area 6K, and print recording is performed by the black ink print head 1K. At the same time, the black ink printing area that has advanced to the position of q becomes the overlapping printing area 6KC of the black ink and the cyan ink, and the cyan ink that is the first color ink print head is arranged on the black ink that has already been printed and recorded. The print records from the ink print head 1C are overlaid. However, at the leading edge of the recording paper 4, the cyan ink print head 1C
Ink is ejected only from the nozzles corresponding to the position q.

Similarly, the third head scanning is performed while the recording paper has advanced to the position r due to the conveyance of the print recording width D of the recording paper. In this head scan, as shown in the print sample, the new print area becomes the black ink print area 6K, and print recording is performed by the black ink print head 1K. At the same time, from the boundary between the black ink print area 6K and the black and cyan ink overlapping print area 6KC, the cyan ink print head 1 is placed on the black ink already printed and recorded.
The print records from C are overlaid. In the cyan ink print head 1C in this case, print recording is performed by all the nozzles. Further, the black ink / cyan ink print area that has advanced to the position of r becomes the overlapping print area 6KCM of the black ink, cyan ink, and magenta ink.
The print record from the magenta print head 1M is overlaid on the black ink and the cyan ink which have already been print-recorded. Also in this case, at the leading edge of the recording sheet 4,
The magenta print head 1M ejects ink only from nozzles corresponding to the position r.

Further, the recording sheet is conveyed, and the fourth head scanning is performed in a state where the recording sheet has reached the position s. In this head scan, since the yellow ink print head 1Y has not reached the print area of the recording paper, the new print area becomes the black ink print area 6K as shown in the print sample, and the black ink print head 1K prints and records. Is performed. At the same time, the print recording by the cyan ink print head 1C and the magenta ink print head 1M is performed in the overlapping print area 6 of the black ink and the cyan ink.
Overprinting is performed on the overprinting area 6KCM of KC, black ink, cyan ink, and magenta ink.

Further, the recording sheet is conveyed, and the fifth head scanning is performed in a state where the recording sheet has reached the position of t. In this head scan, as shown in the print sample, the new print area becomes the black ink print area 6K, and print recording is performed by the black ink print head 1K. At the same time, the print recording by the cyan ink print head 1C, the magenta ink print head 1M, and the yellow ink print head 1Y is performed by the black ink / cyan ink overlapping print area 6KC, the black ink, cyan ink, magenta ink overlapping print area 6KCM, and the black ink. ink,
The cyan ink, magenta ink, and yellow ink are overprinted on the overprinting area 6KCMY.

Thereafter, as shown in the print sample of,
Print recording by each print head is performed simultaneously. At the end of the recording paper, from the time when the black ink ejecting nozzle reaches the end position, the black ink print head 1K sequentially finishes printing and recording, and the print recording width of the yellow ink ejecting nozzle reaches the end of the paper. When the printing is performed, the printing on the entire surface of the paper is completed, and the printed paper is ejected to the outside of the machine.

Also in this embodiment, when the color superposition order for full-color printing is black ink, cyan ink, magenta ink, and yellow ink,
The order of color superposition performed when the carriage on which the print head is mounted is scanned over the paper from the initial predetermined position, and color superposition performed while the carriage is scanned from the position on the opposite side and returns to the initial position. The same color reproduction can be achieved in reciprocal scanning printing as in unidirectional printing.

Further, according to the printing process using this head structure, color recording is performed every time the recording paper is conveyed by the amount corresponding to the print recording width. Therefore, even when ink or paper having poor permeability is used, A sufficient time difference for at least one scan of the head can be provided until the next ink is overprinted, and it is possible to prevent an image quality defect such as ink bleeding that has occurred during color overlay. Since the time difference until color superimposition can be made the same, the color tone can be made the same for each print recording width, and the print quality can be made the same.

Further, since the reciprocal print recording is possible, even in the case of color printing, the print recording speed can be doubled as compared with the first to third embodiments, and high speed printing is possible. Recording is now possible. In the case of reciprocal printing, it is of course necessary to change the timing of data supplied to the black ink print head and the color ink print head between the forward and backward passes.

Also in this head configuration, ink is initially supplied even when the order of ink color overlapping is different from the order described above, such as black ink, yellow ink, magenta ink, and cyan ink. The object can be achieved only by changing the position of the ink to be filled in the ink tank portion, and the print head can be configured without restricting the order of color ink color overlapping.

Further, as shown in FIG. 4A, only the black ink print head, which is frequently used, is used for a single color,
When printing and recording, the number of nozzles that eject ink is set to 5N. Therefore, the print recording width can be made 5 times as large as when full color printing is performed,
At this time, the paper is also conveyed by a feed width that is five times as wide as when full-color printing is performed, so the print recording speed is
It is four times the recording speed when one-way printing of full color printing is performed. Further, when reciprocal printing is performed, the recording speed is improved by about 10 times the recording speed when full-color printing is performed in one direction.

FIG. 9 is a perspective view of a specific example of the head structure in the sixth embodiment. 7, those parts that are the same as those corresponding parts in FIG. 7 are designated by the same reference numerals, and a description thereof will be omitted. Reference numeral 9 is a non-ink jetting area. Even in this embodiment, the heat dissipation plate 8 does not necessarily have to be provided.

[0075]

As is apparent from the above description, according to the present invention, a print head is provided with a single-color ink print head and a color ink print head, and the number of nozzle arrays and the installation structure are changed to change the print head depending on the print mode. By selecting, and by further selecting the head scanning mode, the paper transport mode can be freely selected, so that the printing speed at the time of single-color printing can be increased and the image blurring between ink colors There is an effect that defects can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first embodiment of an inkjet recording apparatus of the present invention.

FIG. 2 is an explanatory diagram of a second embodiment of the inkjet recording apparatus of the present invention.

FIG. 3 is an explanatory diagram of a third embodiment of the inkjet recording apparatus of the present invention.

FIG. 4 is an explanatory diagram of a fourth embodiment of the inkjet recording apparatus of the present invention.

FIG. 5 is an explanatory diagram of a fifth embodiment of the inkjet recording apparatus of the present invention.

FIG. 6 is an explanatory diagram of a sixth embodiment of the inkjet recording apparatus of the present invention.

FIG. 7 is a perspective view of a specific example of a head configuration according to the fourth embodiment.

FIG. 8 is a perspective view of a specific example of the head configuration in the fifth embodiment.

FIG. 9 is a perspective view of a specific example of the head configuration in the sixth embodiment.

FIG. 10 is an explanatory diagram of a print recording width in the print head.

[Explanation of symbols]

1 print head, 1K black ink print head, 1
C cyan ink print head, 1M magenta ink print head, 1Y yellow ink print head, 2 carriage, 3 print head scanning direction, 4 recording paper, 5
Paper transport direction, 6K black ink print area, 6KC
Overprinting area of black ink and cyan ink, 6K
CM Black ink, cyan ink, magenta ink overlay print area, 6K CMY black ink, cyan ink, magenta ink, yellow ink overlay print area, 7 ink jet nozzles, 8 heat dissipation plate, 9 non-ink jet area.

Claims (9)

[Claims] 1. An ink jet recording apparatus having a single color ink print head and a plurality of color ink print heads, wherein the number of nozzles of the single color ink print head is larger than that of the color ink print head. . 2. The ink jet recording apparatus according to claim 1, wherein the number of nozzles of the single color ink print head is at least twice the number of nozzles of the color ink print head. 3. The ink jet recording apparatus according to claim 1, wherein the plurality of color ink print heads are arranged in a line and arranged side by side with the single color ink print head. 4. The ink jet recording apparatus according to claim 1, wherein the single-color ink print head is arranged such that its nozzles project toward the paper supply side more than the color ink print head. 5. The inkjet according to claim 4, wherein the protrusion amount of the nozzle of the single-color ink print head corresponds to a print recording width that is the same as the print recording width of the color ink print head. Recording device. 6. When the print information sent to the ink jet recording apparatus is monochromatic print information, printing is executed by all nozzles of the monochromatic ink print head, and when the sent information is color information, a black ink head. 6. The ink jet recording apparatus according to claim 5, wherein the nozzles are used only for the nozzles corresponding to the portions protruding from the color ink print head to perform printing. 7. A protrusion amount of a nozzle of the single color ink print head corresponds to a sum of a print recording width of the color ink print head and a width of a non-ink jet area provided between the color ink print heads. The ink jet recording apparatus according to claim 4, which is characterized in that. 8. An ink jet recording apparatus capable of independently performing single color ink print recording and color ink print recording, wherein each color ink print record has a print recording width in one scan of the head when performing single color ink print recording. The ink jet recording apparatus is characterized in that it is not less than the total print recording width in one scan of the head. 9. The ink jet recording apparatus according to claim 8, wherein the print recording width at the time of single-color ink print recording is an integral multiple of the print recording width of one head at the time of color ink print recording.