JPH08127138A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE: To realize an image of high-image quality by a low density recording head by scanning a recording head wherein (m) sets of nozzle rows of the same pitch (d) are separated by (n-1/m).d in a paper feed direction in directions crossing each other at a right angle to perform paper feed of predetermined quantity and setting (m) and (n) to specific integers. CONSTITUTION: A head consists of two nozzle groups 101, 102 and 64 nozzles arranged in one row at the pitch interval corresponding to 360dpi in each of the nozzle groups so as to be separated by (32-1/2)d in a paper feed direction and the space between the nozzle groups become a non-printing region 103 being a shading part. In the first scanning recording, only 50% of all of pixels and all of data is recorded on recording paper 201 by the nozzle group 101 consisting of 64 nozzles and the printing paper is fed by d×64 in the direction shown by an arrow. In the second recording scanning, in the printing region where the printing paper is fed by d×64, an unprinted line is adapted to the respective nozzles of the nozzle group 101 and, after the second recording scanning, the printing paper is again fed by d×64 and, this time, all of the nozzles of the nozzle groups 101, 102 are used to apply printing to respective printing regions.

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 for performing high resolution recording.

[0002]

2. Description of the Related Art With the spread of copiers, word processors, computers, and other information processing equipment, and communication equipment, as one kind of image forming (recording) equipment for these equipment, digital image recording by an ink jet system is performed. Is rapidly spreading. In such a recording apparatus, in order to improve the recording speed, a recording head (hereinafter referred to as a multi-head) in which a plurality of recording elements are arranged in an array is used in which a plurality of nozzles (ink ejection ports) and liquid paths are integrated. . As a correspondence to a color image, there are a multi-head provided with a plurality of colors and arranged in parallel in the print scanning direction of the head, and a multi-head provided with a nozzle group of a plurality of colors.

FIG. 36 is a diagram showing a configuration in which a multi-head and an ink tank are arranged in parallel in the print scanning direction.
FIG. 37 is a head configuration diagram of the multi-head shown in FIG. 36 as viewed from the printing surface side (conventional example 1). The four nozzle groups may be integrated in the same head or may be separable. In either case, since the nozzle groups for each color are arranged at a fixed distance, it is easy to adopt a configuration in which the ink tanks are replaced independently for each color. In the configuration in which the head and the tank are integrated for each color, only the cartridge of the worn color (head and ink tank) needs to be replaced. If the ink tank can be separated from the head, Only the ink tank needs to be replaced.

However, in the multi-head having this structure, the area that can be printed by one recording scan is the same for each color,
There is a problem that the joint portion for each recording scan appears in the same portion for all colors, and the joint stripe is emphasized. In addition, since the color tone is different between the case where the colors are superposed in the order of black, cyan, magenta, and yellow and the case where the colors are reversed, reciprocal recording is difficult, and a special printing method is required to realize it.

As a method for solving the above-mentioned joining streak, there has already been proposed a configuration in which nozzle groups of four colors are arranged in parallel while being displaced from each other by a predetermined distance in the paper feeding direction as shown in FIG. 38 (conventional example 2). . According to this, since the joint portions of each color appear at different positions on the paper surface, the joint stripes are inconspicuous. However, since the print areas of the respective colors are slightly overlapped in the paper feed direction, the same consideration as in the configuration of FIG. 37 is required to perform bidirectional printing.

FIG. 39 shows an arrangement in which nozzle groups for four colors are arranged in a row in the same multi-head in the paper feed direction (conventional example 3). With this configuration, the area that can be printed by one recording scan is different for each color, and the colors are always superimposed on the paper surface in a fixed order regardless of the printing direction of the head. Therefore, reciprocal printing can be realized relatively easily. Further, by adjusting the distance d ′ between the nozzle groups of each color so that the connecting portions for each color are displaced from each other, the connecting stripes can be made inconspicuous.

However, it is difficult to replace the ink tank for each color as in the configuration of FIG. 36, because the ink flow path to the ejection port is very close for each color. Therefore, it is general to have a tank configuration with all colors integrated. In this case, one of
There is an inconvenience that the ink tanks must be replaced at the same time for all the colors when the ink is exhausted. If d'is set large, it is possible to use tanks for each color, but if the number of nozzles required to obtain a sufficient printing speed is provided, the multi-head for four colors becomes long and the apparatus becomes large. .

As described above, in order to cope with the colorization of the recording apparatus, the head structure as described above has been proposed and realized.

By the way, in recent years, there has been an increasing demand for multi-valued and high-resolution images as a part of high-quality images at the same time as the support for color images.

For multi-value conversion, a method has been proposed in which the same color and the same color are applied to the same pixel in a plurality of steps of density and volume. In this case, it is practically difficult to eject ink of different densities and amounts from the same nozzle, and the method of ejecting plural kinds of ink from plural nozzle groups is simple and easy to realize. Figure 40 for color
As described above, each color head is composed of a plurality of nozzle groups, and each nozzle group ejects ink of different density and volume (conventional example 4). In order to achieve the desired ejection, the nozzle groups may be arranged at a distance from each other, or the ejection openings may be slightly different in size and internal configuration.

With respect to the demand for high resolution, it is difficult to produce a pixel having a density equal to the required pixel density due to the manufacturing limit of the multi-head integration density. Therefore, some ideas of a head configuration and a printing method for obtaining a high-resolution image without forming a multi-head with high density have already been proposed.

1979 "Xerox Disclosure Jounal"
According to March / April Volume 4, Number 2, 120 dp
When the nozzle interval of the head of i (dots / inch) is λ, (2 + 1/2) λ paper feed is performed, and printing is performed in the same area by two recording scans before and after this paper feed,
The image of dpi is completed (conventional example 5). Further, in particular, in this document, it is devised to suppress the influence of the non-ejection nozzle on the image by setting the feed amount to (2 + 1/2) λ instead of 1 / 2λ.

Further, in Japanese Patent Laid-Open No. 3-45350, Iwasawa uses a plurality of discharge nozzles arranged corresponding to a pitch twice the print line pitch, and the paper feeding means uses m times the recording line pitch ( However, it is disclosed that m is a feed amount corresponding to an odd number of 3 or more (conventional example 5). Here, taking bidirectional printing using color ink as an example, to prevent uneven color tone due to the reverse order of the color ink in the forward and backward passes and to prevent quality deterioration due to variations in the ink discharge amount seen between nozzles. The purpose is to prevent.

In the methods of Conventional Example 4 and Conventional Example 5, the image resolution is increased by controlling the paper feed amount in units of half the nozzle pitch, but in both cases two different paper feed amounts (high It is necessary to alternately control the paper feed for resolution and the paper feed for changing the recording area, which is more complicated than the normal paper feed in which the same amount is repeated. Also,
Since it is necessary to perform two print scans and a paper feed for the same image area, the print time is almost doubled as compared with the case of printing by one print scan.

Further, as a method of forming an image having a resolution twice the nozzle pitch, there is also a configuration in which two nozzle rows are provided in one head and these are displaced by a half pitch in the paper feed direction ( Conventional example 6). In this case, for the same image area, an image with a desired resolution can be completed by only one printing scan, so that the throughput (printing amount per unit time) does not drop. Further, since the paper feed amount need only be repeated a fixed amount, the control is also the same as the conventional one. However, there is a drawback that the head width is larger than usual, and the recording scan width and the recording apparatus itself must be increased accordingly. Further, in this method, instead of printing with two recording scans while drying the ink as in Conventional Example 4 and Conventional Example 5, all the ink drops of the desired resolution are ejected with one recording scan. , Conventional example 4,
Compared with Conventional Example 5, ink bleeding is slightly inferior and the image density is also low.

[0016]

SUMMARY OF THE INVENTION The present invention has been made under such circumstances, and when the high density image is formed by using the low density recording head, the conventional example 4 and the conventional example are used. One of the objects is to solve problems such as complicated paper feed control and dot bleeding as in No. 5, and to realize high image quality.

Further, even in the same recording apparatus, it is recognized that it is necessary to deal with various cases such as black only printing in which throughput is emphasized and color printing in which a large number of sheets are completed in a short time. It has one other purpose.

[0018]

In order to achieve the above object, the present invention provides an ink jet recording apparatus as described in the following (1)-
Configure as in (4).

(1) There are m sets of nozzle rows in which a plurality of nozzles are arranged at the same pitch d in the paper feed direction, and these m sets of nozzle rows are mutually arranged in the paper feed direction (n-1 / m). a recording head arranged at a distance of d, scanning means for repeatedly scanning the recording head in a direction orthogonal to the paper feed direction, and d
An ink jet recording apparatus comprising: a paper feeding unit that repeatedly feeds a predetermined amount that is an integer multiple of n, where m is an integer of 2 or more and n is an integer of 1 or more.

(2) There are m sets of nozzle rows in which a plurality of nozzles are arranged at the same pitch d in the paper feed direction, and the m sets of nozzle rows are mutually (n-1 / m) in the paper feed direction. A recording head in which a plurality of nozzle units arranged at a distance of d are arranged in a direction orthogonal to the paper feeding direction, a scanning unit for repeatedly scanning the recording head in a direction orthogonal to the paper feeding direction, and an integral multiple of d An inkjet recording device, wherein m is an integer of 2 or more and n is an integer of 1 or more.

(3) The ink jet printer according to (1) or (2), further comprising a head driving means for driving the recording head so that the same pixel row in a direction orthogonal to the paper feeding direction is formed by a plurality of nozzles. Recording device.

(4) The recording head has thermal energy generating means for causing the ink to undergo a state change due to heat and ejecting the ink from the nozzle based on the state change. The inkjet recording device according to any one of 1.

[0023]

With the configurations (1) to (4), it is possible to form pixels at a pitch of d / m in the paper feed direction while using a recording head having a nozzle pitch d. With the configuration (3), it is possible to eliminate density unevenness due to variations in the ejection characteristics for each nozzle.

[0024]

EXAMPLES The present invention will be described in detail below with reference to examples.

(Embodiment 1) The present invention is an "ink jet recording apparatus" for recording an image of 720 dpi by using a head equivalent to 360 dpi.

FIG. 19 is a perspective view showing the construction of the printing section in the ink jet recording apparatus of this embodiment. In the figure, reference numeral 701 is an ink cartridge. here,
It is composed of an ink tank filled with four color inks, black, cyan, magenta, and yellow, and a multi-head 702.

Reference numeral 703 denotes a paper feed roller, which is an auxiliary roller 704.
At the same time, the printing paper (also referred to as recording paper) 707 is rotated while rotating in the direction of the arrow in the drawing, and the printing paper 707 is fed in the y direction as needed. Further, reference numeral 705 denotes a paper feed roller, which not only feeds the printing paper but also plays a role of suppressing the printing paper 707 like the rollers 703 and 704. A carriage 706 supports four ink cartridges and moves them together with printing. This is to stand by at the home position h at the position shown by the dotted line in the figure when not printing or when performing multihead recovery work.

Before the start of printing, the carriage 706 at the home position prints on the paper surface by the n multi nozzles on the multi head 702 while moving in the x direction when a print start command arrives. When the printing of the data up to the end of the paper is completed, the carriage returns to the original home position and printing is performed again in the x direction. Alternatively, in the case of reciprocal printing, the next printing is also performed at the stage of moving in the -x direction. From the end of the first printing to the start of the second printing, the paper feed roller 703 rotates in the arrow direction to feed the paper in the y direction by a predetermined width.
In this way, by repeating the carriage scan (also referred to as recording scan, head scan, and main scan) and the paper feed (also referred to as paper feed scan and sub scan), data printing on one paper surface is completed.

The head for this embodiment shown in FIG. 1 is composed of two nozzle groups 101 and 102, and each nozzle group has a pitch equivalent to 360 dpi, that is, d = 70.6.
64 nozzles are arranged in a line at intervals of μm.
Then, these two nozzle groups are (32−1 / 2) × d
However, the non-printing areas 103 (hatched portions) are arranged between them in the paper feeding direction. Here, the two nozzle groups have exactly the same shape and are for ejecting ink of the same color.

A printing state in the head and the ink jet recording apparatus will be described with reference to FIGS. 2 and 3.

In the first recording scan, the print paper 201 is 6
By using the four nozzle groups 102, 50
Only% is recorded. The dot landing state at this time is shown in FIG. 720 dpi equivalent in the head scanning direction,
That is, the dots are arranged at an interval of 35.3 μm, but in the nozzle arrangement direction, an interval corresponding to 360 dpi d = 70.6 μm.
It is an array of.

After completion of the first recording scan, the print paper is fed by d × 64≅45.2 mm in the direction of the arrow in FIG. At this time, the upper half of the area printed in the first recording scan is the nozzle group 10
1 is in the print area, but the lower half is the non-print area 103
Located within.

In the second printing scan, in the nozzle group 101, the remaining 50% data is embedded in the area where 50% data is already printed. Since the nozzle groups 101 and 102 are separated from each other by d × (32−1 / 2), in the print area where the paper is fed by d × 64, a line that has not been printed yet is exactly in each nozzle of the nozzle group 101. Will be adapted. At the same time, the same printing as the first printing scan is performed in the nozzle group 102 on the subsequent printing area on the paper surface.

After the end of the second recording scan, the paper is fed by d × 64 again, and this time, printing is performed in each print area by using all the nozzles of the nozzle groups 101 and 102.

As described above, a 720 dpi image can be formed using a head equivalent to 360 dpi by repeating the paper feed of d × 64 and the recording scan by the two nozzle groups.

According to this embodiment, the above-mentioned conventional example 4,
Unlike the conventional example 5, it is not necessary to control two different paper feeds in units of a half of the nozzle pitch, and always achieve the same purpose as the conventional examples 4 and 5 with a feed amount of d × 64. You can

Further, since the two nozzle groups are fixed in advance by being displaced by a half nozzle pitch, the prior art example 4,
The same nozzle group (head) does not scan the same pixel area twice each as in the conventional example 5. Therefore, the throughput is almost the same as the case of forming an image of 360 dpi with 64 nozzles.

Further, since the two nozzle groups are arranged in the paper feeding direction rather than the head scanning direction, the head scanning width and the recording apparatus main body width do not increase.

Further, the recording of the same image area is not completed by the same scan, but the image is completed by 50% by two recording scans with at least one paper feed scanning interposed therebetween. It is also possible to form an image with high density and high color development.

Further, in the present embodiment, the two nozzle groups are arranged so as to be separated from each other by d × (32−1 / 2), that is, a distance which is a half of the printing area of each nozzle group. It is not limited to. If there are more than (1 + 1/2) nozzles, the effect of the present invention can be always obtained in combination with the paper feed of the print area width of each nozzle group (d × 64 in this embodiment). For example, if it is separated by a distance of (64-1 / 2) nozzles, one non-printing scan is always inserted between two print scans for the same print area, so that there is less bleeding and high density. You can expect the image.

However, as shown in FIG. 2, if the distance between the two is half the distance (32-1 / 2) d of the nozzle group, then 2
The position of the connecting portion of the two nozzle groups (101 is a dotted line, 10
2 is represented by a solid line), and they can appear alternately at equal intervals. This configuration has the effect of dispersing the black stripes of the two nozzle groups and making the joints inconspicuous.

However, as described above, when the interval between the nozzle groups 101 and 102 is (64-1 / 2) d, the joint portion of the nozzle group 101 and the joint portion of the nozzle group 102 appear adjacent to each other. Therefore, while the density of the entire image is high,
There is a fear that the connecting stripes will be noticeable. Therefore, the interval of the nozzle group is exactly half (32d here) of the nozzle group as in the present embodiment, or the interval (n × 64d + 32d) to which this value is added by the integral multiple of the width of the nozzle group If (64n + 32-1 / 2) d is set, the same effect on the connecting lines as in the present embodiment appears.

However, since the above-described connecting stripes are conspicuous and the image is adversely affected in one part of the recording medium, two nozzle groups may be formed depending on the situation such as the overall density and the size of the head. The distance and the number of nozzles may be configured.

Further, the fact that the distance between the nozzle groups is large to some extent as in the present embodiment makes it possible to print with different types of ink from each nozzle group by replacing the ink tank. Such ink tank replacement will be described later.

As described above, according to this embodiment,
By using a head having a configuration in which two nozzle groups having 64 nozzles corresponding to 360 dpi are separated by (32-1 / 2) d in the paper feeding direction, and performing normal printing of paper feeding for 64 nozzles, 720 dpi is obtained. Images can be printed.

(Embodiment 2) Incidentally, in forming an image image, various elements such as color developability, gradation and uniformity are important in addition to resolution in order to improve image quality. Particularly regarding uniformity, a slight variation in nozzle unit caused by a difference in multi-head manufacturing process affects the ink ejection amount and the direction of the ejection direction of each nozzle when printing, and finally the printed image This causes the image quality to deteriorate as uneven density.

Therefore, here, as a modification of the first embodiment,
An example using multi-pass printing for preventing image deterioration will be described as a second embodiment. Multi-pass printing (divided printing)
The method will be described in detail in Example 10 below.

FIGS. 4 and 5 are views showing the printing state of the 2-pass printing according to the present embodiment. In this embodiment, the paper feed amount is 32d.
Then, the recording scan and the paper feed are repeated five times in the same printing area. The head configuration is the same as that of the first embodiment.

In the first print scan, the lower side 3 of the nozzle group 102
Two nozzles record 25% of data. The dot landing state at this time is as shown in FIG. Similar to the recording method in the first embodiment, the pitch d = 70.5 μm in the paper feed direction.
Although the dots are arranged in the line, the dots are recorded in a state of being thinned out by one dot in the head scanning direction.

After the paper feed scan of 32d, the upper 32 nozzles of the nozzle group 102 complement the remaining dots of the same line as shown in FIG. If you do this,
Since the dots lined up on the same line in the head scanning direction are recorded by two types of nozzles, the requirement for the ejection characteristics of each nozzle is relaxed.

In the next third recording scan, the printing area described above is located just in the non-printing area 103, and new dots are not printed. But in the next two print areas,
Each 25% is recorded as shown in FIGS. 5 (a) and 5 (b).

In the fourth recording scan, the print area is located at the lower 32 nozzles of the nozzle group 101, and 2 nozzles are used for these print areas.
5% of data is recorded. Since the nozzle groups 101 and 102 are separated by (32-1 / 2) d, a line which has not been printed yet in this printing area is exactly in each nozzle of the nozzle group 101 as in the printing method of the first embodiment. Adapted, dots are embedded every other pixel in the unprinted line as shown in FIG.

The image of the print area in the fifth recording scan is completed by the upper 32 nozzles of the nozzle group 101 as shown in FIG. 5D.

Thereafter, the paper feed of 32d and the recording scan of 25% are alternately repeated, whereby the respective print areas are sequentially completed.

According to the multi-pass printing of this embodiment, the printing time is about twice as long as that of the normal printing method described in the first embodiment. However, preventing unevenness of the image due to nozzle variation,
An image with better uniformity can be obtained. Also, 2
The joints of two nozzle groups appear at the same position, but the joints of each nozzle group are dispersed in two places beforehand, so
There are few adverse effects as a connecting stripe.

Embodiment 1 in which multi-pass printing is not performed
Then, as already shown in FIG. 2, the intervals of the two print scans are different for each print area. The upper 32d of the area where 50% is printed by the first recording scan prints the rest by the second recording scan, but the lower 32d is the third area after leaving one scan time.
The remaining 50% is recorded by the recording scan. Such a difference in printing interval becomes a difference in density, and may be perceived as density unevenness depending on the recording paper.

Also in this respect, the multi-pass printing of this embodiment is effective. In the case of the 32d feed multi-pass as shown in FIG. 4, all the print areas are printed at the same timing in the first, second, fourth, and fifth times, so that all print areas have the same density.

Although an example of 2-pass printing with 32d feeding is given here, 16d feeding 8-pass printing is also effective as a modification, and the image becomes smoother as the number of recording scans is increased.

As described above, according to this embodiment, 3
By performing multi-pass printing using a head having a configuration in which two nozzle groups having 64 nozzles corresponding to 60 dpi are separated by (32-1 / 2) d nozzles in the paper feeding direction, 7
It is possible to print a 20 dpi image with high quality.

(Embodiment 3) This embodiment has two heads used in Embodiment 1. As a result, similar to the first embodiment, 720 dpi is realized and higher quality recording is realized at the same time cost.

The head structure used in this embodiment is shown in FIG. Here, there are two heads, Bk1 and Bk2, and Bk2
Is installed by being offset from Bk1 by 32d in the paper feed direction.

The dot landing state in this embodiment is also shown in FIG. The printing method of this embodiment will be described below with reference to FIGS. 7 and 5. As shown in FIG. 7, in the present embodiment, the paper feed amount is 64d as in the first embodiment. However, the image is completed by recording 25% each with four nozzle groups on Bk1 and Bk2. In the first print scan, Bk1 and Bk
25% of data is recorded on the paper surface 201 by the nozzle groups 102 on the lower sides of the two. At this time, since the two heads are displaced from each other by an integral multiple of d (32d), the two nozzle groups 102 land dots on the same line. For example, if the Bk1 head records data thinned in half in the head scanning direction as shown in FIG. 5A, Bk2 records the other half of the data, and the dot landing state at that stage is shown in FIG. (B) of.

According to FIG. 7, in the first recording scan, only the Bk1 is printed on the lower side 32d of the print area, and is printed by both Bk1 and Bk2 on the upper side 32d. Therefore, on the lower side 32d, 2 as shown in FIG.
Only 5% of the landing state is recorded, and the upper 32d has a landing state of 50% recording as shown in FIG. 5B.

After the paper feed scan of 64d, two heads print again 25% each as the second print scan. In the two print areas recorded in the states of FIGS. 5A and 5B in the first recording scan, data of 25% each is further added, and FIGS. 5B and 5B respectively. The state of (c) of 5 is obtained. At the same time, 25% and 50% images are printed in the print area following the area, as in the first print scan.

In the subsequent third recording scan after the paper feed scan of 64d, the two print areas are completed up to 100%. That is, in the area of the upper side 32d already printed up to (c) in FIG. 5, the remaining 25% of data is added by Bk2, resulting in the state of (d) in FIG. At the stage of the second recording scan, in the area of the lower side 32d in the state of FIG. 5B,
Both Bk1 and Bk2 are printed at the same time, as shown in FIG.
(D) state. Further, the printing area following the two areas is printed in the same manner as the first and second printing scans.

An image having a width of 64d is completed by the above-described three print scans and the paper feed of 64d.

Below, 64d for each of the subsequent printing scans
The image in the print area of will be completed.

Further, in FIG. 6, the two heads are 32d apart from each other.
Although it is explained that they are deviated by just (3)
The same effect can be obtained even if it is deviated by 2-1 / 2) d. In this case, the printing method is the same as in FIG. 7, but
The dot landing state is as shown in FIG. After the 50% print scan is completed, all print pixels of 720 dpi are arranged in a staggered grid pattern ((b) of FIG. 8).

When the dots are landed in such an order, since the dots that are continuously recorded do not overlap each other, it is a method that can be expected in terms of bleeding of different color ink on the paper surface and increase of the density. Is.

According to the present embodiment, two heads similar to those of the first embodiment are used, and an image is completed by three recording scans and a paper feed of 64d. Therefore, the throughput is the same as that in the first embodiment. However, in the present embodiment, printing of the same line is recorded by two nozzles in the head scanning direction. Therefore, it is possible to prevent the deterioration of the print image quality due to the variation of the nozzle units caused by the difference in the multi-head manufacturing process, and it is possible to obtain a higher quality image.

(Embodiment 4) With the head structure as in Embodiment 3, black highlight printing can be realized with the same throughput as that in Embodiment 1. This example will be described as Example 4. The printing method in this case is shown in FIG.
In the above-described method, each head performs 25% thinning printing, whereas in this black enhancement mode, each head performs the same thinning printing as in the first embodiment. However, in this embodiment, since there are two black heads, each has 10
The image becomes 200% in increments of 0%.

In such black enhancement, two dots ejected from different nozzles overlap each other at the same landing point, so that it is possible to prevent deterioration of image quality due to nozzle variations without thinning printing. it can.

As described above, also in the black emphasizing printing of this embodiment, it is possible to obtain a high-quality image without density unevenness due to nozzle variations, with the same throughput as in the first embodiment.

(Embodiment 5) In addition to the black ink printing method of Embodiment 4, a method of efficiently printing color ink will be described as Embodiment 5. For the three colors of cyan, magenta, and yellow, which are used as color inks, when forming an image of 720 dpi as in the case of black,
For each color, the same head as in Example 1 may be used.
However, in the present embodiment, as for the color ink, a case of forming an image of 360 dpi using only two heads will be described.

FIG. 10 is a block diagram of the four-color head of this embodiment. As described above, Bk1 for black
And print with two heads of Bk2. The remaining two shown in the figure
Although the head is for color, it has the same head configuration as Bk1 and Bk2. Yellow ink is applied to the nozzle group 101 of the YM head, and cyan ink is applied to the nozzle group 102 of the MC head. Also, the lower half 32 nozzles of the MC head 101 and the upper 32 nozzles of the YM head 102 are combined to eject magenta ink, and the other 64 nozzles are not used in this print mode. Further, the Bk1 and MC heads are installed at the same position with respect to the paper feeding direction, whereas the YM head is displaced by (32-1 / 2) d in the paper feeding direction. Therefore, all 64 nozzles of the M head separated into two are also arranged in the paper feed direction at a pitch of d.

FIG. 20 will be described as an internal structure for ejecting a plurality of different inks from the same recording head. One end of the wiring board 200 is mutually connected to the wiring portion of the heater board 100, and the other end of the wiring board 200 is provided with a plurality of electric / thermal energy converters for receiving electric signals from the main body device. Individual heads are provided. As a result, the electric signal from the main body device is supplied to each electric / thermal energy converter. The metal support 300 that supports the back surface of the wiring board 200 on a plane serves as a bottom plate of the inkjet unit. The restraining spring 500 is a claw that is caught by using a portion formed by bending it in a U-shaped cross section and an escape hole provided in the base plate in order to elastically press the region near the ink ejection port of the groove top 1310 on the line. The base plate has a pair of rear legs that receive the force acting on the spring. Due to this spring force, the wiring board 200 can be mounted in the groove 1
310 is pressed. Wiring board 200 for support
Is attached by using an adhesive or the like.

A filter 700 is provided at the end of the ink supply pipe 2200. The ink supply member 600 is formed by molding, and the channel 13 that guides the ink to the orifice plate portion 1300 and each ink supply port is provided in the groove 1310.
500 is integrally formed. Ink supply member 60
0 is fixed to the support 300 by the ink supply member 60.
Two pins (not shown) on the back surface side of 0 are projected through the holes 1901 and 1902 of the support 300, respectively, and these are heat-fused to easily perform this. At this time, the gap between the orifice plate portion 1300 and the supply member 600 is sealed, and further passes through the groove 310 provided in the support base 300,
The gap between the orifice plate portion 1300 and the front end portion of the support base 300 is completely sealed.

FIG. 21 is a perspective view of the groove top 1310 of the recording head used in this embodiment as seen from the heater board 100 side. A plurality of liquid chambers are provided, and each liquid chamber has a wall 10
The groove 30 is provided on the pressure contact surface with the heater board 100. This groove communicates with the outer peripheral portion of the groove top 1310.
After the groove ceiling 1310 is pressed against the heater board and brought into close contact with the heater board, the outer peripheral portion is sealed with the sealant as described above. On this occasion,
The sealant penetrates along the groove to form the groove top 1310.
And fill the gap between the heater board 100. In this way, the liquid chamber can be completely separated by the technical process conventionally used in the head. The structure of this groove differs depending on the physical properties of the sealant, and it is necessary to make the shape corresponding to each. By separating the liquid chamber into a plurality of chambers in this manner, different inks can be ejected to the respective ink ejection ports, and therefore, the same black ink, different color inks, or same dark and light inks are ejected from the same head. be able to.

FIG. 11 shows a color ink printing method in this embodiment. As shown in the figure, in this embodiment, one color ink is completely printed in the printing area of 64d by one printing scan. Then, in three consecutive print scans, cyan,
Recording of all magenta and yellow colors is completed.

Even in such color printing, 64d
Since the recording of all the images is completed by the paper feeding of 3 and the recording scanning of three times, it is possible to proceed with both black printing of the third and fourth embodiments at the same time.

In the conventional recording apparatus having the color heads arranged in parallel in the recording scanning direction (conventional example 5), two or more color inks are ejected in the same printing area in the same recording scanning.
In the reciprocating print scan of the head, the order of driving on the paper surface is reversed. However, it is difficult to realize reciprocal printing with a recording apparatus having such a configuration, because the color tone is usually different when the order in which two or more color inks are applied to the paper surface is reversed.

However, as seen in FIGS. 10 and 11, the color heads of this embodiment are completely separated in the paper feeding direction without being arranged in parallel in the recording scanning direction. Therefore, two or more color inks are not ejected in the same printing area in the same recording scan, and the above-mentioned problems do not occur even in reciprocal printing. In this embodiment, the color image can be printed back and forth, and the throughput can be increased accordingly.

(Sixth Embodiment) Further, while using the same head structure as in the fifth embodiment, the user replaces the ink tank,
By supplying two types of inks having different densities into the above-described two separated liquid chambers, it is possible to perform multi-value color recording of 360 dpi. This example will be described as Example 6.

A method of multi-value recording using inks of the same color but different densities is already known. However, the density may differ depending on the order in which the high density ink and the low density ink are ejected. In this case, the desired density may not be expressed, or a unique texture may occur and the image quality may deteriorate. It was In contrast,
In the invention of Japanese Patent Application No. 5-102759 filed by the present applicant, these problems are solved and the centers of ink dots of similar colors having different densities adhered on the recording medium do not coincide in order to realize high image quality. It is specified here, and means for this, a recording method and a recorded matter are proposed here.
Then, as an example thereof, the nozzles of the dark ink and the light ink which are lined up on the same head are configured to be shifted by 3/8 pixel in the paper feeding direction, and the nozzle row width of the dark ink and the light ink (4
By feeding paper (corresponding to pixels), the light and dark dots that have landed do not completely overlap.

According to this embodiment, it is possible to realize a color multi-valued mode in which dark inks and light inks of respective colors are ejected as separate printing modes while having the above-described head configuration and printing mode with high resolution.

FIG. 12 shows the ejected ink color of each nozzle group in this print mode. Here, four recording heads are assigned to black, cyan, magenta, and yellow, respectively, and a dark ink and a light ink of each color can be ejected to each recording head. Here, the light ink of each color is ejected to the lower nozzle group and the dark ink is ejected to the upper nozzle group so that the dark ink is landed on the paper surface after the light ink. Further, since the upper and lower nozzle groups are displaced by (32-1 / 2) d, the recording is such that the dark ink dots and the light ink dots land at positions displaced by d.

In the printing method of this embodiment, since the nozzle groups in each head are preliminarily displaced by 32d, the joints of dark ink and light ink of each color appear at different positions. Further, since the two heads of black, magenta and cyan, and yellow are offset from each other by approximately 32d, the connecting stripes for each color also appear at different positions.

(Seventh Embodiment) The multi-pass printing described in the second embodiment can be applied to the printing mode of the sixth embodiment. This example will be described as Example 7. In the case of 2-pass printing of 32d paper feed, as in the case of multi-pass printing in the second embodiment, one recording scan time is allowed from the completion of recording of the light ink to the printing of the dark ink for any color. High density recording is possible. Therefore, gradation can be improved at the same time.

Further, the recording apparatus having such a head structure may be provided with a black-only printing mode having a high throughput as described below as another black printing mode.

In FIG. 6, the total length of the black printable area of Bk1 and Bk2 is 191.5d.
In the print mode proposed here, the nozzles of Bk1 and Bk2 existing in 191.5d are combined, and recording is performed by a total of 191 or 192 nozzles arranged in the paper feeding direction. In the portion where the nozzle groups Bk1 and Bk2 are arranged in parallel in the head scanning direction, either one of the nozzles is used.

In this method, the recording scan and the 191d or 192d paper feed scan are alternately performed to obtain 360 dp.
Black printing of i can be realized at high speed. The printing time is about 1/3 as compared with the printing mode of the 64d paper feed described above.

However, in the head configuration of this embodiment, 191.
Since one portion of the 5d where the nozzle pitch d is deviated by 1 / 2d appears, if this portion becomes noticeable as white stripes or black stripes, an image may be generated depending on the total ink ejection amount or the like. The harmful effects may be inconspicuous.

(Embodiment 8) An example in which an image of 1080 dpi is recorded by a nozzle group having a nozzle pitch of 360 dpi will be described as Embodiment 8. FIG. 13 is a diagram showing the configuration of the head used in this embodiment. The head of this embodiment is composed of three nozzle groups 1101, 1102, 1103, and each nozzle group has 60 nozzles arranged in a line at a pitch corresponding to 360 dpi, that is, at an interval of d = 70.6 μm. There is. The three nozzle groups are arranged apart from each other by (20-1 / 3) × d in the paper feeding direction, and the non-printing areas 1104 and 1105 are provided between them.
(Hatched area). Here, it is assumed that the three nozzle groups have exactly the same shape and eject ink of the same color.

Print states in the head and the recording device will be described with reference to FIGS. 14 and 15. In the first recording scan, the printing paper 201 is moved by the nozzle group 1103 of 60
Only 33% of all pixels and all data are recorded. The dot landing state at this time is shown in FIG. The dots are aligned in the head scanning direction at a distance of 1080 dpi, that is, at an interval of 23.5 μm, but in the nozzle arrangement direction, an interval of d = 70.6 μm corresponding to 360 dpi is formed.

After the completion of the first recording scan, the printing paper 201 is fed by d × 60 = 42.3 mm in the direction of the arrow in the figure. At this time, the upper 2/3 of the area printed in the first recording scan is 110
Although it falls within the print area of 2, the lower 1/3 is the non-print area 110
Located within 5.

In the second printing scan, at 1102, a new 33% is written in the area where 33% of the data is already printed.
Embed% data. The dot landing state at this time is shown in FIG. Nozzle groups 1102 and 1103
Since they are separated from each other by d × (20-1 / 3), d ×
In the print area fed by 60, the lines that have not yet been printed are applied to the nozzles 1102. At the same time, with respect to the image area on the paper that follows, 1103
In, the same printing as in the first printing scan is performed.

After the end of the second recording scan, the paper is fed by d × 60 again, and this time, printing is performed in each recording area using all the nozzles 1101, 1102, 1103.

In the third print scan, at 1101, a new 33% is added to the area where 67% of the data has already been printed.
% Data will be embedded. The dot landing state at this time is as shown in FIG. 15C, which completes the recording of all image data. Since the nozzle groups 1101 and 1102 are separated from each other by d × (20-1 / 3), d × 6
In the print area where the paper is fed by 0, the lines that have not been printed are applied to the nozzles 1101. At the same time, for the image area on the paper that follows, 1102
In 1103, the same printing as in the first printing scan is performed.

As described above, according to this embodiment, 3
1080 dpi is obtained by repeating recording scanning using a head having a configuration in which three nozzle groups having 60 nozzles corresponding to 60 dpi are separated by (20-1 / 3) d in the paper feeding direction and paper feeding for 60 nozzles. It becomes possible to print the image of the high quality.

Also in the head structure of this embodiment, it is effective to perform multi-pass printing in order to improve the image quality, as in the second embodiment. In the case of the head configuration of this embodiment, 2-pass printing of 30d feeding or 3-pass printing of 20d feeding can be considered.

(Embodiment 9) In order to record the image data of 360 dpi more smoothly and to emphasize it, 7
A method of interpolatively recording dots corresponding to 20 dpi will be described as a ninth embodiment.

When embedding circular dots in square pixels arranged at a pitch of 360 dpi, a combination in which adjacent two dots have the longest distance is a case where they are arranged on a diagonal line. In this embodiment, basically, interpolation dots are added between these two dots to improve the linearity in the diagonal direction. FIG. 16 is a diagram showing the recording method of the present embodiment, and shows at what dot arrangement and at which position interpolation dots are added.

Next, the emphasis printing method will be described as a modification of the ninth embodiment. Normally, recording at 360 dpi is designed so that one dot completely covers a pixel of 360 dpi and two diagonally adjacent two dots are sufficiently in contact with each other, as shown in FIG. In general emphasizing printing, emphasizing dots are further printed at the same position on these dots to increase the density.

However, in this modification, as shown in FIG. 17B, one pixel of 360 dpi is composed of two dots which are shifted in the diagonal direction. Thus, as shown in FIG. 17C, if two dots to be emphasized in advance are not recorded at the same landing point, a white non-printed surface is unlikely to remain even if some dot shift occurs, and the paper surface is efficiently printed. Can be buried.

According to this printing method, for example, as shown in FIG.
As shown in 8, even if the dot size is such that the 360-dpi pixel is not completely covered, two dots arranged diagonally form one dot.
Since the pixels can be configured ((b) of FIG. 17), it is possible to efficiently increase the density while suppressing the ink amount.

In the smoothing and emphasizing printing described here, interpolation dots and emphasizing dots may be recorded by the nozzle group 102 as in the printing method shown in FIG. At this time, the nozzle group 101 ejects ink at a constant timing corresponding to the print scanning speed for a 360-dpi image, but the nozzle group 102 that prints in the same scan as the nozzle group 101 prints at a timing with a half-shifted ejection timing interval. Thus, a half pixel shift in the head recording scanning direction can be realized.

(Head Driving Method) Here, a driving circuit and method for ejecting ink which can be used in each of the above embodiments will be described. FIG. 22 is a block diagram showing an ink ejection drive circuit in the inkjet recording apparatus of the present invention. The head unit 100 sets the print data Si in the 8-bit shift register 101 with the print data synchronization clock CLKi, and sets BEi1 ^* , BEi2 ^* , BE.
By turning on the i3 ^* and BEi4 ^* signals respectively,
The transistor array 103 of the head unit section 100 is driven to cause the heater 104 to generate heat and eject ink.
The LATCH ^* signal is a control signal for latching print data in the latch circuit 102, and the CARESi ^* signal is a reset signal for clearing the latch.

One heat of each nozzle is Heat Tr
It starts with the igger signal. The pulse generator 106 is B
Signals are output with respect to each of Ei1 ^* , BEi2 ^* , BEi3 ^* , and BEi4 ^* while being temporally shifted. Therefore, since the nozzle groups divided into four groups are also heated while being shifted in time, the power capacity consumed simultaneously can be saved.

In the driving of such a head, the influence on the output image is slightly different depending on which pulse is driven by which nozzle of the nozzle group arranged in parallel. FIG. 23 shows two head driving methods using 16 nozzles for simplicity.

23A and 23B show an example of distributed driving. It is configured such that every four nozzles are heated at the same time. Of the four timings, the nozzle that is heated at the earliest time is taken as the nozzle, and the nozzles that discharge are followed. Since the recording head ejects while moving, the heat timing deviation slightly affects the landing position as shown in the figure. At this time, in the block structure of (a), rattling occurs every four pixels and the linearity is impaired, but in the structure of (b), a somewhat smooth straight line is obtained. Therefore, it can be said that the method of (b) is excellent in the method of dispersing the simultaneous heat nozzles as much as possible.

Further, FIG. 23C is a block drive diagram, and is constructed such that four consecutive nozzles simultaneously heat. In this case, the linearity in the head is good, but a large deviation occurs between the adjacent lines printed by another scan, and rattling occurs for each nozzle row. In such a case, good linearity can be obtained by inclining the nozzle array in the head in advance according to the drive timing and the shift amount as shown in FIG.

The above embodiments can be realized by the driving method having such a configuration. For example, in Example 1 and Example 2,
A signal is generated from the pulse generator 106 at a constant driving frequency to form a 720 dpi image. This frequency is the nozzle refill frequency limit, power capacity, image resolution,
Alternatively, it is determined by the carriage scanning speed or the like.

In the third embodiment, since one row of data is completed by the two print heads in the print scanning direction, the number of heat given to each nozzle is half that in the first embodiment. The data may be thinned out by providing a flip-flop in the head unit to mask the print data for each heat of the Heat Trigger, or by thinning out the data sent from the data signal Si in advance. Anything is fine.

When data is thinned out in this way, the driving frequency of each nozzle is practically half of that in the first embodiment if the thinning-out method is as shown in FIG. At this time, if the printing speed is limited by the nozzle refill frequency rather than the carriage speed or the power supply capacity, the printing speed can be doubled by doubling the carriage speed. However, the driving timing and speed are the same as those in the first embodiment when black is emphasized in the fourth embodiment.

In the ninth embodiment, the same pixel is formed by two dots that are displaced by half a pixel. Therefore, when the print area recorded by the nozzle group 102 is recorded again by 101, the Hea
The heat timing of tTrigger may be shifted by half a pixel. Also in this case, since the head driving frequency is halved as in the third embodiment, double speed printing is possible.

(Embodiment 10) FIG. 24 is a structural diagram of a head used in the "ink jet recording apparatus" of Embodiments 10 to 13. This multi-head is composed of eight nozzle groups (G1 to G8), and each nozzle group is composed of 64 nozzles arranged at a pitch interval of 360 dpi (d≈70 μm). Each nozzle group is positioned as shown in the figure with a distance of 32d or (32-1 / 2) d, and these are integrated on the multi-head.

Further, the ink tank can be replaced for each nozzle group independently. The combination of these ink tanks and nozzle groups is determined according to the desired mode, and various printing methods can be realized.

FIG. 25 shows an example of the above combination. Here, only black is 720 dpi and color is 360 d.
It has a configuration for printing with pi. G1 to G4 eject black ink, G6 ejects yellow ink, and G7 ejects cyan ink. G5 and G8 correspond to magenta ink, but only the lower half of G5 and the upper half of G8 are actually used.

Here, a brief description will be added to the divided printing method. Unlike a monochrome printer that prints only characters, various elements such as color developability, gradation, and uniformity are required to print an image. Particularly regarding uniformity, a slight variation in nozzle unit caused by a difference in multi-head manufacturing process affects the ink ejection amount and the direction of the ejection direction of each nozzle when printing, and finally the printed image This causes the image quality to deteriorate as uneven density.

A specific example will be described with reference to FIGS. In FIG. 26A, reference numeral 91 is a multi-head, and here, for simplicity, it is assumed that it is composed of eight nozzles 92. Reference numeral 93 is an ink droplet ejected from the nozzle 92, and normally, it is ideal that ink is ejected in a uniform direction with a uniform ejection amount as shown in this figure. If such a recording is made,
As shown in (b) of FIG. 26, dots having the same size are landed on the paper surface, and as shown in (c) of FIG. 26, a uniform image without density unevenness is obtained as a whole. However, in reality, each nozzle has a variation, and if printing is performed as it is, the size and direction of the ink droplets ejected from each nozzle as shown in FIG. Variation occurs, and the paper is landed on the paper surface as shown in FIG. 27 (b). According to this figure, there are periodically blank portions that cannot satisfy the area factor of 100% in the head scanning direction, and conversely dots are overlapped more than necessary, or FIG.
There are white stripes as seen in (b). A collection of dots landed in such a state has a density distribution shown in FIG. 27C with respect to the nozzle array direction, and as a result, these phenomena cause density unevenness as far as human eyes can see. Is perceived.

Therefore, as a countermeasure against this density unevenness, the following method is generally taken. This will be described with reference to FIGS. 28 and 29. According to this method, the multi-head is scanned three times to complete the printing area shown in FIGS. 26 and 27, and the half area of the unit of 4 pixels is completed in two passes. In this case, the 8 nozzles of the multi-head are
The dots, which are divided into groups of nozzles and lower 4 nozzles, and which are printed by one nozzle in one scan, are obtained by thinning out prescribed image data by about half according to a predetermined image data array. Then, at the time of the second scanning, the head is embedded in the remaining half of the image data to complete the printing of the 4-pixel unit area. The recording method as described above is called a divided recording method. If such a divided recording method is used, even if the same recording head as that used in FIG. 27 is used, the effect on the print image peculiar to each nozzle is halved, so the printed image is shown in FIG. As shown in FIG. 27B, black stripes and white stripes as shown in FIG. 27B are less noticeable. Therefore, the density unevenness is considerably reduced as compared with the case of FIG. 27A as shown in FIG. 28C.

When such division printing is performed, the image data is divided in the first scan and the second scan so as to fill each other according to a certain arrangement, but here, for simplification, the arrangement state (thinning pattern) is shown. As shown in FIG. 29, a pixel having a staggered pattern is used for each vertical and horizontal pixel. Therefore, in the unit print area (here, in units of 4 pixels), printing is completed by the first scan for printing the zigzag lattice and the second scan for printing the inverse zigzag lattice. 29 (a), (b), and (c) of FIG.
Similar to FIGS. 26 to 28, how the recording of a certain area is completed when the reverse zigzag pattern is used is described using a multi-head having 8 nozzles. First, in the first scan, the lower 4 nozzles are used to print a staggered pattern ((a) of FIG. 29). Next, in the second scan, the paper is fed by 4 pixels (1/2 of the head length) to record an inverted zigzag pattern ((b) in FIG. 29). Further, in the third scan, the paper is fed by 4 pixels (1/2 of the head length) again, and the staggered pattern is recorded again ((c) in FIG. 29). In this manner, the paper feed in units of 4 pixels and the recording in the staggered and reverse zigzag patterns are alternately performed in this manner, whereby the recording region in units of 4 pixels is completed for each scanning. As described above, by completing printing with two different types of nozzles in the same area, it is possible to obtain a high-quality image without density unevenness.

In the above, as the divisional printing method, the structure in which the image is completed in the same area by the two printing scans has been described. Such a two-divided division recording method is often used when it is desired to record a color image quickly without having a low absorption capacity like plain paper.

However, the effect of the divided recording method on the image quality becomes more apparent as the number of divisions is increased. Even when plain paper is desired to have high image quality, or when it is coated paper or glossy paper. When the recording medium itself is expensive, the number of pixels printed by one scan may be further halved, and the width of the paper feed scan may be set to 2 pixels (1/4 of the head length). In this case, since the image is completed by four kinds of nozzles in the same scanning direction, it is possible to obtain a smoother and better image although the printing speed is inferior. In addition, by printing the same area a plurality of times in this way, an image can be completed while reliably fixing a small amount of ink on an OHP (overhead projector) film or the like having low ink absorbency. It is possible to prevent not only the bleeding at different color boundaries but also the peeding phenomenon in which ink droplets that are not completely absorbed are fixed as large lumps of ink droplets that can be visually recognized on the medium surface due to the surface tension. it can.

In one method of this embodiment, only the black color is divided into two parts by the divided recording method, and the paper is fed by 32 d.
By performing each of them, the divided recording printing consisting of four passes of 720 dpi and the one pass printing of 360 dpi for color are realized.

FIG. 30 shows a printing state with the head configuration shown in FIG. This method is bidirectional printing, and for simplicity, it is assumed that each nozzle group is composed of eight nozzles.
The paper feed amount is also 8d. Since black dots are recorded at a resolution twice that of color (720 dpi), the dots are shown smaller in the figure, but in reality, they may be printed with an ejection amount equivalent to color to emphasize them.

Black is printed stepwise by the reciprocal printing scan from the first printing scan to the third printing scan by the four nozzle groups Bk1 to Bk4. Since Bk1 and Bk2 are displaced by 4d in the paper feeding direction, the degree of completion of the image on the paper differs between the lower 4d width and the upper 4d width in the first recording scan. In the lower 4d width, only Bk1 is printed, and ink is landed at a pitch of d both vertically and horizontally. The upper 4d width of Bk1 and Bk2 land ink at a pitch of 1 / 2d in the horizontal direction and a pitch of d in the vertical direction. Since both nozzle groups are displaced by an integer multiple (4d) of d, printing is performed on the same recording scan line.

In the second printing scan after the paper feed of 8d, printing is performed by Bk2 and Bk3 in the first printing area, and the second printing area following this is similar to the first printing area in the first printing scan. Is recorded. In the area 4d below the first recording area, the complementary dots not printed in the first recording scan are B
It is printed by k2. In the upper 4d area, the dots having the pitch d are recorded by Bk3 which is located at a position displaced by 1 / 2d in the paper feeding direction.

Further, in the third recording scan after the paper feed of 8d, the image in the first recording area is completed by Bk3 and Bk4. Similarly to Bk3, Bk4 is also displaced by half a pixel from Bk2, and prints the same recording scan lines as Bk3 in half numbers.

As described above, since the two nozzle groups are arranged with a shift of half a pixel (1/2) in advance, the paper feed of 4d is always repeated, and the recording of 720 dpi, which is a resolution twice the nozzle pitch, is performed. Can be realized.

In addition, even in the same recording scan line, Bk
Since two types of nozzles such as 1 and Bk2 or Bk3 and Bk4 are used to perform half-division printing (that is, two-division printing), it is possible to reduce print unevenness for each nozzle that occurs during head manufacturing.

Next, a method of printing color ink will be described.
The color ink completes a 360-dpi image in one printing scan for each printing area of each color. Compared with black ink, color ink is relatively inconspicuous in image unevenness caused by nozzle variations at the time of head production, and thus such a printing method is used. In the configuration of this embodiment, since the respective color inks are located in a state where they do not completely overlap in the paper feeding direction, yellow, magenta,
Ink is ejected in the order of cyan. Therefore, even if bidirectional printing is performed, there is no image adverse effect such as color unevenness due to the difference in the order in which colors are printed, and recording can be completed in a considerably faster time than in unidirectional printing.

In the color head, yellow,
The printing position of magenta is shifted from the printing position of cyan by half a pixel in the paper feed direction. This does not adversely affect the color image to be completed, but the order in which the ink is ejected and the printing at a position shifted by half a pixel from other colors may affect the tint of the entire image. In this embodiment,
The printing order of each color ink is not particularly specified, and the printing position of each color is variable. For example, if a better color can be obtained by landing the yellow at a position half pixel shifted from the other two colors, the yellow ink may be made to correspond to the magenta position in the drawing in advance or the cyan ink When it is better to print the uppermost on the paper surface, cyan ink may be associated with the position G6.

Furthermore, if color nozzle unevenness is to be reduced and the image quality is to be further improved, the paper feed amount for each recording scan is set to 4 d so that divided recording can be performed even for color images.
In addition to this, the number of print dots in each print scan may be further reduced by half. If you do this, 2 for color ink
The division printing and the black division result in four division printing, and the printing speed is inferior to that of the above-mentioned example, but it becomes possible to obtain a smoother and high quality image.

As described above, the greater the number of divided recordings, the higher the image quality and the longer the printing time. The head configuration of FIG. 24 can also be dealt with after various divisions according to the image state and purpose.

According to the head structure shown in FIG. 25, the structure shown in FIG.
In addition to the printing method shown in (1), several printing methods according to different applications can be realized. When a color image is recorded as in the above example, only a paper feed amount of 64d width or less can be realized, but with black ink only, the paper feed amount is 64d.
Need not be. According to FIG. 25, the printable area of the black ink is always the width of G4 to G1 (about 192d).
Therefore, when printing an image of 360 dpi in one pass, as shown in FIG. 31, the maximum width is 196 d.
The paper feed amount can be realized. By doing so, the printing time can be shortened to about 1/3 times as long as that in the color printing described above.
However, in this case, the dots forming the 360 dpi image have two types of dots that are offset from each other by 1 / 2d, 96d each, so that there is a possibility that the connecting portion of each 96d will appear as white or black lines. is there. However, it can be said that the printing method is sufficiently effective in the case where the throughput is emphasized, and particularly in the case of a monochrome image in which characters and ruled lines of any quality are printed.

(Embodiment 11) Further, there is a method of setting the paper feed amount to 96d as a mode for completing a 720dpi image more speedily even though it is a black only mode. This example will be described as Example 11.

As shown in FIG. 32, in the head configuration of FIG. 25, one scan is performed with 96 nozzles composed of Bk1 and Bk2 and 96 nozzles composed of Bk3 and Bk4 which are in a relationship shifted by 1 / 2d from them. Each is recorded to obtain an image of 720 dpi. In this case, in the area where the nozzle groups do not overlap at all in the print scanning direction, each nozzle is independently set to 1
It is necessary to record a pitch of / 2d, but Bk1
Since Bk2 and Bk2 and Bk3 and Bk4 overlap each other by 32d in the paper feed direction, it is necessary to select whether to use one nozzle group at all for this portion or to divide the recording for both portions. Become.

As described above, even in the same tank configuration as shown in FIG. 25, a plurality of printing modes can be realized depending on the application.

(Embodiment 12) FIG. 33 is an illustration of a recording method of an "ink jet recording apparatus" which is Embodiment 12. This embodiment has a high resolution of not only black but also color 7.
The present invention realizes a method for realizing 20 dpi or a method for performing multivalue recording. In this embodiment, the two nozzle groups arranged in parallel in the paper feed direction eject the same ink, and the paper feed amount is always 64d. In this figure, the image is completed in the first to third printing scans, and the divided printing in each printing scanning direction is not performed.

Further, in the present embodiment, the Y ink is applied to G7 and G8 which are deviated from other colors by 1 / 2d, but this is not limited, and which ink is judged from the tint state. May be assigned.

Of course, it is also effective to set the paper feed amount to 32 d or less and perform the divided recording in order to realize higher image quality. In particular, with the head configuration of FIG. 33, in the case of a paper feed amount of 64d, it is impossible to make the ink color firing order constant for each recording area. However, if the recording is divided and the thinning mask for each ink color is independently set, the problem of color unevenness can be reduced and bidirectional printing can be performed.

Although the printing method corresponding to the image signal of 720 dpi for each color has been described here, the head configuration of FIG. 33 is also effective for multi-value recording of 360 dpi. In this case, since one pixel of 360 dpi can be configured with 4 dots, it is possible to handle up to a 5-value image. Furthermore, if it is possible to make the ejection amount different for each nozzle group by controlling the driving pulse of the nozzle group, it is possible to deal with even more multivalued images.

Of course, neither multi-valued recording nor high-quality recording is performed,
It is also possible to perform color division recording in which the print ratio of each print scan is reduced to 1/2, and the print ratio remains unchanged at 360
It is also possible to support a mode in which the image of dpi is simply emphasized. Such an emphasizing mode is particularly effective when the color of the ink dye is different from that of a normal recording medium such as an OHP sheet or cloth.

(Embodiment 13) FIG. 34 is an explanatory diagram of a recording method in Embodiment 13. The present embodiment is a method different from the above-described multi-valued printing, in which high-quality multi-valued expression is performed using two kinds of ink of the same color having different densities. Since such a multi-valued expression can be recorded with a light ink, especially on the low duty side, it is effective in obtaining a smooth high image quality in a natural image because the granular feeling due to the high density ink is eliminated.

A method for multi-value recording using inks having the same color but different densities has already been known.
However, the densities may differ depending on the order in which the high-density ink and the low-density ink are ejected. In this case, the desired density may not be expressed, or a unique texture may occur and image quality may deteriorate. It was In contrast,
In the invention of Japanese Patent Application No. 5-102759 described above, it is necessary to improve these problems and prevent the centers of ink dots of similar colors having different densities adhering to the recording medium from being aligned in order to achieve high image quality. And the means for this purpose, the recording method and the recorded material are provided here. Then, as an example thereof, the nozzles of the dark ink and the light ink which are lined up on the same head are displaced by 3/8 pixel in the paper feed direction,
By feeding the paper only by the width of the nozzle row of the dark ink and the light ink, it is configured so that the landed light and dark dots do not completely overlap.

In the present embodiment, if the ink tanks are distributed as shown in FIG. 34, the dark ink dots and the light ink dots can land at positions which are naturally displaced by half a pixel, and therefore, in Japanese Patent Application No. 5-102759. The described printing configuration can be easily realized.

In FIG. 34, dark ink is printed after light ink is printed. This is a printing order that is effective in making the granular feeling of dark ink inconspicuous, but this is not limited, and when you want to make the resolution higher, when you want to obtain sharpness of character quality, When it is desired to increase the overall height, dark ink may be printed first, or different ink colors may be used.

In this embodiment, since the nozzle groups in each head are preliminarily displaced by 32d, the dark ink and light ink joints of each color always appear at different positions. Further, since the two heads of black, magenta and cyan, and yellow are offset from each other by approximately 32d, the connecting stripes for each color also appear at different positions.

The above-described divisional recording can also be applied to this print mode. If the 2-pass printing of 32d is performed, there is one recording scan time from the completion of recording of the light ink to the printing of the dark ink for any color, and recording with more stable density becomes possible.

As described above, by constructing eight nozzle groups consisting of 64 nozzles as shown in FIG. 24, and changing the type or the ejection amount of the ink tank corresponding to each nozzle group. The various printing modes described above can be realized by the same recording device. Of course,
Each print mode can be realized by a separate recording device.

FIG. 35 shows a list of the ink types and the maximum paper feed amount of each nozzle group for the various printing modes described in the tenth to thirteenth embodiments.

(Related Art of the Present Invention) The present invention brings excellent effects particularly in a recording head and a recording apparatus of a system utilizing thermal energy among ink jet recording systems.

Regarding its typical structure and principle, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal that corresponds to the recorded information and gives a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling occurs on the heat acting surface of the recording head. This is effective because the bubbles can be generated and, as a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. When the drive signal has a pulse shape, the growth and shrinkage of the bubbles are immediately and appropriately performed, so that it is possible to achieve the ejection of the liquid (ink) with excellent responsiveness, which is more preferable. This pulse-shaped drive signal is disclosed in U.S. Pat. No. 4,463,359 and No. 43.
Those as described in 45262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise of the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The present invention can be implemented in the configuration disclosed in the specification of No. 59600. In addition, for multiple electrothermal converters,
Japanese Unexamined Patent Publication No. 59-123670, which discloses a configuration in which a common slit is used as the discharge portion of the electrothermal converter, and Japanese Laid-Open Patent Publication No. 59-63, which discloses a structure in which an opening for absorbing a pressure wave of thermal energy is associated with the discharge portion. The effect of the present invention is effective even with a configuration based on Japanese Patent Laid-Open No. 138461.

[0156]

As described above, according to the present invention, it is possible to realize a high-quality image finer than the nozzle pitch of the recording head by complicated paper feeding and bleeding of dots. Further, in the invention described in claim 2, it is possible to realize various high-quality print modes with the same apparatus. In the invention described in claim 3, density unevenness due to variation in ejection characteristics of nozzle units is eliminated. You can

[Brief description of drawings]

FIG. 1 is a configuration diagram of a head used in Examples 1 and 2.

FIG. 2 is an explanatory diagram of a recording method according to the first embodiment.

FIG. 3 is a diagram showing a dot landing state in the first embodiment.

FIG. 4 is an explanatory diagram of a recording method according to a second embodiment.

FIG. 5 is a diagram showing a dot landing state in Example 2 and Example 3;

FIG. 6 is a configuration diagram of a head used in a third embodiment.

FIG. 7 is an explanatory diagram of a recording method according to a third embodiment.

FIG. 8 is a diagram showing a dot landing state according to a modification of the third embodiment.

FIG. 9 is an explanatory diagram of a recording method according to a fourth embodiment.

FIG. 10 is a configuration diagram of a head used in Example 5.

FIG. 11 is an explanatory diagram of a recording method according to a fifth embodiment.

FIG. 12 is a configuration diagram of a head used in a sixth embodiment.

FIG. 13 is a configuration diagram of a head used in Example 8.

FIG. 14 is an explanatory diagram of a recording method in Example 8.

FIG. 15 is a diagram showing a dot landing state in Example 8.

FIG. 16 is an explanatory diagram of a recording method according to a ninth embodiment.

FIG. 17 is an explanatory diagram of a modification of the ninth embodiment.

FIG. 18 is an explanatory diagram of a modification of the ninth embodiment.

FIG. 19 is a diagram showing a configuration of a printing unit according to the first embodiment.

FIG. 20 is a perspective view showing the internal structure of the head in the fifth embodiment.

FIG. 21 is a perspective view of a groove in the head of FIG.

FIG. 22 is a block diagram of a head drive circuit usable in each embodiment.

FIG. 23 is an explanatory diagram of a head driving method that can be used in each example.

FIG. 24 is a diagram showing the arrangement of nozzle groups used in Examples 10 to 13;

FIG. 25 is a diagram showing an example of a combination of the nozzle group of FIG. 24 and an ink tank.

FIG. 26 is an explanatory diagram of uneven density.

FIG. 27 is an explanatory diagram of uneven density.

FIG. 28 is an explanatory diagram of divided printing.

FIG. 29 is an explanatory diagram of divided printing.

FIG. 30 is an explanatory diagram of a recording method according to the tenth embodiment.

FIG. 31 is an explanatory diagram of a black recording method with the head configuration of FIG. 25.

FIG. 32 is an explanatory diagram of a recording method according to the eleventh embodiment.

FIG. 33 is an explanatory diagram of a recording method according to the twelfth embodiment.

FIG. 34 is an explanatory diagram of the recording method in the thirteenth embodiment.

FIG. 35 is a diagram showing each ink type and maximum paper feed amount in Examples 10 to 13;

FIG. 36 is a configuration diagram of a multi-head and an ink tank of Conventional Example 1.

FIG. 37 is a head configuration diagram of Conventional Example 1.

38 is a head configuration diagram of Conventional Example 2. FIG.

FIG. 39 is a head configuration diagram of Conventional Example 3.

FIG. 40 is a head configuration diagram of Conventional Example 4.

[Explanation of symbols]

 101, 102 nozzle group 103 non-printing area

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B41J 2/13 B41J 3/04 103 B 104 D

Claims (4)

[Claims] 1. A plurality of nozzles have m sets of nozzle rows arranged at the same pitch d in the paper feed direction, and the m sets of nozzle rows are mutually (n−1 / m) · d in the paper feed direction. A recording head arranged to be separated from each other, a scanning means for repeatedly scanning the recording head in a direction orthogonal to the paper feeding direction, and a paper feeding means for repeatedly feeding a predetermined amount of paper of an integral multiple of d. An ink jet recording apparatus, wherein m is an integer of 2 or more and n is an integer of 1 or more. 2. A m number of nozzle rows in which a plurality of nozzles are arranged at the same pitch d in the paper feeding direction, and the m number of nozzle rows are mutually (n-1 / m) .multidot.n in the paper feeding direction. A recording head in which a plurality of nozzle units arranged apart from each other by d are arranged in a direction orthogonal to the paper feeding direction, scanning means for repeatedly scanning the recording head in a direction orthogonal to the paper feeding direction, and an integral multiple of d. An ink jet recording apparatus comprising: a paper feeding unit that repeatedly feeds a predetermined amount of paper, wherein m is an integer of 2 or more and n is an integer of 1 or more. 3. The head driving means for driving the recording head so as to form the same pixel row in a direction orthogonal to the paper feeding direction with a plurality of nozzles. Inkjet recording device. 4. The recording head has thermal energy generating means for causing the ink to undergo a state change due to heat and ejecting the ink from the nozzle based on the state change. Item 5. The inkjet recording device according to any one of items 3.