JP2004243574A - Ink jet recording head and ink jet recording method - Google Patents

Abstract

An object of the present invention is to reduce the displacement of landing of droplets due to an air flow in print recording of small droplets of an ink jet recording head.
In a head having a plurality of ejection port arrays 2 for one ink color, ejection port array 1 performs print recording only at the end of the row, and ejection port array 2 performs print recording at the center of the column. Print recording is performed by combining the printing pass to be performed with the ejection port array 1 only at the center of the row, and the ejection orifice row 2 is performed by combining the printing pass at which printing is performed at the end of the row. By not discharging the end and the center in one spout row at the same time as described above, the landing deviation of the droplet due to the air flow is reduced.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid ejection recording head for applying ink to a recording medium such as paper and a recording method.
[0002]
[Prior art]
Ink jet recording methods widely used today include a method using an electrothermal transducer (heater) and a piezoelectric element (piezo) as a discharge energy generating element used to discharge ink droplets. There are methods that can be used, and in each case, the ejection of ink droplets can be controlled by electrical signals. For example, the principle of an ink droplet discharge method using an electrothermal transducer is that an electric signal is applied to the electrothermal transducer to instantaneously boil the ink near the electrothermal transducer, and to change the phase of the ink at that time. Ink droplets are ejected at high speed by the rapid growth of bubbles. On the other hand, the principle of a method of ejecting ink droplets using a piezoelectric element is that an electric signal is applied to the piezoelectric element to displace the piezoelectric element, and the ink droplet is ejected by the pressure at the time of the displacement. Here, the former method does not require much space for the discharge energy generating element, and has advantages such as a simple structure of the ink jet print head and easy integration of nozzles.
[0003]
[Problems to be solved by the invention]
Recently, the demand for high-speed color images has been increasing due to the increase in the processing speed of personal computers and the spread of the Internet, etc., and the so-called very high-quality recorded matter with high definition or gradation has been rapidly increased. There is an increasing demand for printouts in Japan, and there is a demand for a printer with high image quality and high speed. By the way, in order to obtain a high-definition, high-quality image with gradation, it is appropriate to perform recording by discharging very small ink droplets from one nozzle. It is necessary to repeatedly eject ink droplets from the outlet in a short cycle. Further, the carriage on which the print head is mounted also needs to move at high speed in synchronization with the response frequency of the head. As described above, when recording is performed by repeatedly discharging very small ink droplets from one nozzle, for example, a solid printed portion of a bar graph as shown in FIG. 4, that is, a solid printed portion (hereinafter referred to as a solid portion) Streaks occurred in the image of (noted). The streak portion corresponds to the portion between the n-th operation and the (n + 1) -th operation of the head. FIG. 5B is an enlarged view of a joint portion, and FIG. 5A shows a state in which ink droplets are ejected from the head at this time. FIG. 5 (a) is a line along the dotted line from the angle of the arrow in FIG. Since the image data is solid, the nozzles SEG0 to SEG255 are all driven at a high response frequency. Therefore, due to the ejection of the ink droplets from the nozzles in the end region of the image data, viscous air around the ejected ink droplets also moves at substantially the same speed as the ink droplets. Then, the air in the entire nozzle row moves in the same direction as the ink droplet, and that part is in a reduced pressure state. As a result, air other than around the ejected ink droplets moves in a direction in which the pressure is reduced, and an airflow as indicated by an arrow is generated, and the ejecting direction of the ink droplets of the nozzles in the end region of the nozzle row. Is sprayed toward the center of the nozzle by the airflow. In addition, airflow generated when the carriage moves in the main scanning direction during printing generates an airflow toward the center of the nozzle row, and the ejection direction of the ink droplets of the nozzles in the end area of the nozzle row is shifted toward the center of the nozzle by the airflow. Inject. As a result, there has been a problem that the landing positions are shifted as shown in FIG. Since the landing is disturbed by the airflow, the impact is affected as the ejection volume is smaller, and the effect is remarkable particularly at 8.5 pl or less. In addition, if the amount of ejected ink is increased to prevent streaks, the overflow of ink from the recording paper and the undulation phenomenon due to the absorption of ink from the recording medium occur, and the recorded image deteriorates. Further, in the formation of high-definition and high-resolution images, it is not preferable because it is necessary to reduce the diameter of one dot as much as possible because reduction of graininess and reproduction of fine lines are important. Further, if the cycle of repeatedly ejecting ink droplets is lengthened, the generation of airflow is reduced, but the speed of the printer is reduced, and it has not been possible to meet the user's need for printing out at high speed. The present invention solves these problems, and an object of the present invention is to provide an ink jet recording head that can print at high speed and can reduce streaks in a recorded image.
[0004]
[Means for Solving the Problems]
As a result of detailed studies by the inventor, the following has been found.
[0005]
Not only the nozzles at the end of the nozzle row are distorted, but for example, even if some of the nozzles are ejected as shown in FIG. The part is displaced toward the center of the nozzle being discharged. However, what stands out on the image as shown in FIG. 5 (b) is the portion of the transition between the scans of the print recording, and the edges are particularly problematic.
[0006]
When the number of ejection nozzles at the time of printing and recording decreases, the amount of displacement of the droplets ejected from the nozzles at the end of the image decreases. This is presumed to be because the reduced number of discharge nozzles reduces the reduced pressure state at the center of the discharge nozzles, thereby making it difficult to generate airflow. Specifically, FIG. 7 shows the relationship between the number of ejected droplets and the amount of displacement. In the case of one ejection, there is no deflection in the main scanning direction and the vertical direction due to the airflow, but the deflection amount increases as the number of discharged droplets increases.
[0007]
Further, when the resolution of the print recording in the sub-scanning direction decreases, the amount of displacement of the liquid droplets discharged from the nozzles at the ends decreases.
[0008]
Further, the present inventor conducted a detailed study based on the above-described airflow model. As shown in FIG. 8, when the nozzle at the end and the nozzle at the center were discharged separately, the liquid discharged from the nozzle at the end was It was found that the drop of the droplet was reduced. The premise is that the number of discharge nozzles at the end is reduced as shown in (b) above. This is because, as described above in (b), the influence of the reduced distance at the center of the discharge nozzle and the effect of the airflow due to the scanning of the carriage on the end due to the increased distance reduce the airflow to the end. It is presumed that it is unlikely to occur.
[0009]
Based on the results of these studies, in order to achieve the above object, the present invention relates to an ink jet recording head having a plurality of discharge ports for discharging ink. Specifically, the figure? As shown in FIG. 2, in a head having a configuration suitable for reciprocal printing, such as A: Cyan, B: Magenta, C: Yellow, D: Magenta, and E: Cyan,
In one main scan, the nozzles at the end of the ejection port row 21 to 23 and the nozzle at the center of the ejection port row 31 to 33 in FIG. By performing print recording, the influence of airflow is reduced.
With such a configuration, it is possible to reduce the phenomenon that the ejection direction is bent, and to suppress the occurrence of printing streaks.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 3 is a schematic view of the ink jet recording apparatus of the present invention. A carriage 11 on which the inkjet head cartridge is mounted, a carriage drive motor 12 for scanning and moving the carriage, a flexible cable 13 for sending an electrical signal from a control unit (not shown) of the inkjet device to the inkjet cartridge, and a recovery process for the inkjet head unit. It has a recovery unit 14 for performing printing, a paper feed tray 15 that stores print media such as paper in a stacked state, and an optical position sensor 16 that optically reads the position of the carriage. The ink jet apparatus having such a configuration causes the carriage 11 to serially scan in the main scanning direction orthogonal to the transport direction (sub-scanning direction) of the print medium, and prints a print having a width corresponding to the ejection ports (number of nozzles) of the ink jet head. On the other hand, during non-printing, the print medium is intermittently conveyed by a predetermined amount.
[0011]
(Embodiment 1)
FIG. 10 is a schematic view of an ink jet print head showing a basic mode of the present invention. In the print head of FIG. 10, a plurality of ejection ports 1 are provided, and they are arranged at a predetermined pitch to form ejection port arrays 21 to 23 and 31 to 33 substantially parallel to each other as shown in FIG. 11. Has formed. FIG. 11A is a schematic diagram viewed from above, FIG. 11B is an explanatory diagram for explaining the arrangement of discharge ports, and FIG. 11C is a cross-sectional view. As shown in FIG. 11C, the recording head according to the present embodiment includes a substrate 7 including a heating resistor element 5 as an energy conversion element, and an orifice plate 6 forming an ejection port 1.
[0012]
Here, in FIG. 11A, the i-th ejection port from the drawing of each of the ejection port arrays 21 to 23 coincides with the arrow direction shown in FIG. 11A. As described above, the ejection port arrays 21 to 23 of the present embodiment are arranged such that the corresponding ejection ports coincide with each other in the scanning direction when the recording head is mounted on the recording apparatus and scanned. And a first ejection port array group 20 is formed. The ejection port arrays 31 to 33 are also arranged in the same manner as the ejection port arrays 21 to 23, and the second ejection port group 30 is arranged adjacent to the first ejection port group 20 by the ejection port arrays 31 to 33. Is formed. In the present embodiment, the corresponding ejection ports in these two ejection port row groups are arranged so as to match. Out of the six ejection port arrays, cyan (C) is used in the outermost ejection port arrays 23 and 33, magenta (M) is used in the ejection port arrays 22 and 32, and the innermost adjacent ejection port arrays 21 and 31 are used. In this example, yellow (Y) is discharged. Further, the distance between each ejection port array is 150 μm or more. According to the study of the present inventor, when the distance between the ejection port arrays is short, landing turbulence occurs due to the airflow generated by another ejection port row.
[0013]
In the present embodiment, 128 ejection ports are arranged in each row at a pitch of 1200 DPI, and ink droplets are ejected from the ejection ports toward the medium. The ejection volume of the ejected ink droplet is 4.5 pl, the ink density is 1.05, and the ejection is sufficient to fill the dots at 1200 DPI which is the resolution in the sub-scanning direction (ejection port row) in print recording, and to eliminate white streaks. Volume. Since the resolution in the carriage scanning direction of the ink jet recording apparatus is 1200 DPI and the driving frequency is 12.5 kHz, the moving speed of the carriage is about 265 mm / s. Will do. The distance from the discharge port surface to the paper surface is 1.5 mm. Further, the ink jet recording apparatus performs bidirectional printing.
[0014]
According to the study by the present inventors, as shown in FIG. 7, when the number of ejected droplets is 16 or less, the displacement of the ejected droplet at the end is 9 μm below, and the displacement amount has no problem on the image. Therefore, in the present embodiment, in the ejection port arrays 21, 22, and 23 in FIG. 11A, 16 nozzles at the end of 128 nozzles (that is, a total of 32 nozzles having ejection port numbers 1 to 16 and 113 to 128). ) Are nozzles that can be simultaneously printed during printing in one main scan, and in the ejection port arrays 31, 32, and 33, the center of the nozzle row excluding 16 nozzles at the end of the 128 nozzles is subjected to one main scan. The nozzles can be recorded simultaneously with the print recording. FIG. 1 shows a print recording method when 100% solid printing is performed. By performing such a print recording method, the amount of deflection in the nozzle row direction of the 32 nozzles at the end is reduced to 9 μm from 20 μm for the comparative conventional head, and the carriage scan is performed. Connection streaks are gone.
[0015]
In the present embodiment, the recording of the 16 ejection ports at the end portion may be other than 16 ejection ports. In this embodiment, there are two nozzle rows, but one nozzle row may be used. Further, in the present embodiment, all of the formed discharge ports are used for image formation. However, when there are discharge ports that are not used for image formation as dummy discharge ports, they are used for image formation except for dummy discharge ports. The discharge port to be used is defined as an end.
[0016]
(Embodiment 2)
FIG. 10 is a schematic view of an ink jet print head showing a basic mode of the present invention. In the print head of FIG. 10, a plurality of ejection ports 1 are provided, and are arranged at a predetermined pitch to form ejection port arrays 21 to 23 and 31 to 33 that are substantially parallel to each other. Here, in FIG. 10A, the i-th discharge port from the drawing of each of the discharge port arrays 21 to 23 coincides with the arrow direction shown in FIG. 10A. As described above, the ejection port arrays 21 to 23 of the present embodiment are arranged such that the corresponding ejection ports coincide with each other in the scanning direction when the recording head is mounted on the recording apparatus and scanned. And a first ejection port array group 20 is formed. The ejection port arrays 31 to 33 are also arranged in the same manner as the ejection port arrays 21 to 23, and the second ejection port group 30 is arranged adjacent to the first ejection port group 20 by the ejection port arrays 31 to 33. Is formed. In the present embodiment, the corresponding ejection ports in these two ejection port row groups are arranged with a shift of 1200 DPI. Out of the six ejection port arrays, cyan (C) is used in the outermost ejection port arrays 23 and 33, magenta (M) is used in the ejection port arrays 22 and 32, and the innermost adjacent ejection port arrays 21 and 31 are used. In this example, yellow (Y) is discharged. In such a configuration, color unevenness during reciprocal printing is less likely to occur.
[0017]
In the present embodiment, 128 ejection ports are arranged in each row at a pitch of 600 DPI, and ink droplets are ejected from the ejection ports toward the medium. The ejection volume of the ejected ink droplets is 4.5 pl, the ink density is 1.05, and dots are buried in 1200 DPI, which is the resolution in the sub-scanning direction (ejection port row), in print recording using two ejection port arrays, and white stripes are formed. The discharge volume is sufficient so that no Since the resolution in the carriage scanning direction of the ink jet recording apparatus is 1200 DPI and the driving frequency is 12.5 kHz, the moving speed of the carriage is about 265 mm / s. Will do. The distance from the discharge port surface to the paper surface is 1.5 mm. Further, the ink jet recording apparatus performs bidirectional printing.
[0018]
According to the study by the present inventor, as shown in FIG. 7, when the number of ejected droplets is 16 or less, the displacement of the ejected droplet at the end is 9 μm or less, and the displacement amount has no problem on the image. Therefore, in the present embodiment, when performing multi-pass printing in which an image is filled by a plurality of print scans, in the ejection port arrays 21, 22, and 23 of FIG. (I.e., a total of 32 nozzles with ejection port numbers 1 to 16 and 113 to 128) are nozzles that can be simultaneously recorded during printing in one main scan, and the ejection port arrays 31, 32, and 33 have one end of 128 nozzles. The central part of the nozzle row excluding each of the sixteen parts is a nozzle that can be simultaneously recorded at the time of print recording in one main scan. In another scan, in the ejection port arrays 31, 32, and 33 of FIG. 11A, 16 nozzles at the end of 128 nozzles (that is, a total of 32 ejection port numbers 1 to 16 and 113 to 128) are used. Nozzles) are nozzles that can be simultaneously recorded during print recording in one main scan, and in the ejection port arrays 21, 22, and 23, the center of the nozzle row excluding 16 nozzles at the end of the 128 nozzles is one main scan. Nozzles that can record simultaneously when printing with
[0019]
8 and 9 show a print recording method when 100% solid printing is performed. In the configuration of the present invention, when the ejection port row is 600 DPI per row and the ejection volume is 4.5 pl, 100% solid is not filled in one scan in one row of print recording. A print recording method of performing two scans at a position is shown. FIG. 8 shows the relationship between the print record and the head position, and the print record state by each scan. FIG. 9 assists the explanation of FIG. 8 and shows the ejection port numbers actually printed in each scan. As shown in FIGS. 8 and 9, in the first scan, recording is performed only at the end ejection port of the ejection port array 21 and only at the center ejection port of the ejection port array 31. In this example, the print medium moves in the Y direction, so that the upper half of the desired print area is printed at 100% solid. When the third scan is completed, the entire desired print area is 100% solid printed. By performing such a print recording method, the amount of deflection in the nozzle row direction of the 32 nozzles at the end is reduced to 9 μm from 20 μm for the comparative conventional head, and the carriage scan is performed. Connection streaks are gone.
[0020]
In the present embodiment, the recording of the 16 ejection ports at the end portion may be other than 16 ejection ports. In this embodiment, there are two nozzle rows, but one nozzle row may be used. Further, in the present embodiment, all of the formed discharge ports are used for image formation. However, when there are discharge ports that are not used for image formation as dummy discharge ports, they are used for image formation except for dummy discharge ports. The discharge port to be used is defined as an end.
[0021]
(Embodiment 3)
FIG. 10 is a schematic view of an ink jet print head showing a basic mode of the present invention. In the print head of FIG. 10, a plurality of ejection ports 1 are provided, and are arranged at a predetermined pitch to form ejection port arrays 21 to 23 and 31 to 33 that are substantially parallel to each other. Here, in FIG. 10A, the i-th discharge port from the drawing of each of the discharge port arrays 21 to 23 coincides with the arrow direction shown in FIG. 10A. As described above, the ejection port arrays 21 to 23 of the present embodiment are arranged such that the corresponding ejection ports coincide with each other in the scanning direction when the recording head is mounted on the recording apparatus and scanned. And a first ejection port array group 20 is formed. The ejection port arrays 31 to 33 are also arranged in the same manner as the ejection port arrays 21 to 23, and the second ejection port group 30 is arranged adjacent to the first ejection port group 20 by the ejection port arrays 31 to 33. Is formed. In the present embodiment, the corresponding ejection ports in these two ejection port row groups are arranged with a shift of 1200 DPI. Out of the six ejection port arrays, cyan (C) is used in the outermost ejection port arrays 23 and 33, magenta (M) is used in the ejection port arrays 22 and 32, and the innermost adjacent ejection port arrays 21 and 31 are used. In this example, yellow (Y) is discharged. In such a configuration, color unevenness during reciprocal printing is less likely to occur. In the present embodiment, 256 ejection ports are arranged in each row at a pitch of 600 DPI, and ink droplets are ejected from the ejection ports toward the medium. Further, in the present embodiment, as shown in FIG. 12 in particular, in the ejection port arrays 21 to 23, the ejection port numbers 1 to 16 and 245 to 256 are arranged in odd rows of 1200 DPI pitch, and the ejection port numbers are 17 to 244. Then, they are arranged in even-numbered rows. Further, in the ejection port arrays 31 to 33, the ejection port numbers 1 to 16 and 245 to 256 are arranged in even rows with a 1200 DPI pitch, and the ejection port numbers 17 to 244 are arranged in odd rows.
[0022]
The ejection volume of the ejected ink droplets is 4.5 pl, the ink density is 1.05, and dots are buried in 1200 DPI, which is the resolution in the sub-scanning direction (ejection port row), in print recording using two ejection port arrays, and white stripes are formed. The discharge volume is sufficient so that no Since the resolution in the carriage scanning direction of the ink jet recording apparatus is 1200 DPI and the driving frequency is 12.5 kHz, the moving speed of the carriage is about 265 mm / s. Will do. The distance from the discharge port surface to the paper surface is 1.5 mm. Further, the ink jet recording apparatus performs bidirectional printing.
[0023]
According to the study by the present inventor, as shown in FIG. 7, when the number of ejected droplets is 16 or less, the displacement of the ejected droplet at the end is 9 μm or less, and the displacement amount has no problem on the image. Therefore, in the present embodiment, when performing multi-pass printing in which an image is filled with a plurality of printing passes, in the ejection port arrays 21, 22, and 23 of FIG. (That is, a total of 32 nozzles having ejection port numbers 1 to 16 and 245 to 256) are nozzles that can be simultaneously recorded at the time of print recording in one main scan, and the ejection port rows 31, 32, and 33 have one end of 256 nozzles. The central part of the nozzle row excluding each of the sixteen parts is a nozzle that can be simultaneously recorded at the time of print recording in one main scan. In another pass, in the ejection port arrays 31, 32, and 33 of FIG. 11A, 16 nozzles at the end of 128 nozzles (that is, a total of 32 ejection port numbers 1 to 16 and 245 to 256) are used. Nozzles) are nozzles that can be simultaneously printed during print recording in one main scan, and in the ejection port arrays 21, 22, and 23, the center of the nozzle row excluding 16 nozzles at the end of 256 nozzles is one main scan. Nozzles that can record simultaneously when printing with
[0024]
8 and 2 show a print recording method when 100% solid printing is performed. In the configuration of the present invention, when the ejection port row is 600 DPI per row and the ejection volume is 4.5 pl, 100% solid is not filled in one scan in one row of print recording. A print recording method of performing two scans at a position is shown. FIG. 1 shows the relationship between the print record and the head position, and the print record state by each scan. FIG. 2 assists the explanation of FIG. 8 and shows the ejection port numbers actually printed in each scan. As shown in FIGS. 8 and 2, in the first scan, recording is performed only at the end ejection port of the ejection port array 21 and only in the central ejection port of the ejection port array 31. In this example, the print medium moves in the Y direction, so that the upper half of the desired print area is printed at 100% solid. When the third scan is completed, the entire desired print area is 100% solid printed. By performing such a print recording method, the amount of deflection in the nozzle row direction of the 32 nozzles at the end is reduced to 9 μm from 20 μm for the comparative conventional head, and the carriage scan is performed. Connection streaks are gone. Also, as in the present embodiment, the ejection port pitch is partially changed in one ejection port row. However, for the purpose of this configuration, printing is not performed by a plurality of scans as shown in FIG. In the case where printing is performed with priority given to speed even when the density is low, there is an effect that printing can be performed at the same pitch in one scan.
[0025]
In the present embodiment, the recording of the 16 ejection ports at the end portion may be other than 16 ejection ports. In this embodiment, there are two nozzle rows, but one nozzle row may be used. Further, in the present embodiment, all of the formed discharge ports are used for image formation. However, when there are discharge ports that are not used for image formation as dummy discharge ports, they are used for image formation except for dummy discharge ports. The discharge port to be used is defined as an end.
[0026]
(Embodiment 4)
FIG. 10 is a schematic view of an ink jet print head showing a basic mode of the present invention. In the print head of FIG. 10, a plurality of ejection ports 1 are provided, and are arranged at a predetermined pitch to form ejection port arrays 21 to 23 and 31 to 33 that are substantially parallel to each other. Here, in FIG. 10A, the i-th discharge port from the drawing of each of the discharge port arrays 21 to 23 coincides with the arrow direction shown in FIG. 10A. As described above, the ejection port arrays 21 to 23 of the present embodiment are arranged such that the corresponding ejection ports coincide with each other in the scanning direction when the recording head is mounted on the recording apparatus and scanned. And a first ejection port array group 20 is formed. The ejection port arrays 31 to 33 are also arranged in the same manner as the ejection port arrays 21 to 23, and the second ejection port group 30 is arranged adjacent to the first ejection port group 20 by the ejection port arrays 31 to 33. Is formed. In the present embodiment, the corresponding ejection ports in these two ejection port row groups are arranged with a shift of 1200 DPI. Out of the six ejection port arrays, cyan (C) is used in the outermost ejection port arrays 23 and 33, magenta (M) is used in the ejection port arrays 22 and 32, and the innermost adjacent ejection port arrays 21 and 31 are used. In this example, yellow (Y) is discharged. In such a configuration, color unevenness during reciprocal printing is less likely to occur.
[0027]
In the present embodiment, 128 ejection ports are arranged in each row at a pitch of 600 DPI, and ink droplets are ejected from the ejection ports toward the medium. The ejection volume of the ejected ink droplets is 4.5 pl, the ink density is 1.05, and dots are buried in 1200 DPI, which is the resolution in the sub-scanning direction (ejection port row), in print recording using two ejection port arrays, and white stripes are formed. The discharge volume is sufficient so that no Since the resolution in the carriage scanning direction of the ink jet recording apparatus is 1200 DPI and the driving frequency is 12.5 kHz, the moving speed of the carriage is about 265 mm / s. Will do. The distance from the discharge port surface to the paper surface is 1.5 mm. Further, the ink jet recording apparatus performs bidirectional printing.
[0028]
According to the study by the present inventor, as shown in FIG. 7, when the number of ejected droplets is 16 or less, the displacement of the ejected droplet at the end is 9 μm or less, and the displacement amount has no problem on the image. Therefore, in the present embodiment, when performing multi-pass printing in which an image is filled by a plurality of print scans, in the ejection orifice rows 21, 22, and 23 of FIG. Each of the 16 nozzles at the end (that is, a total of 32 nozzles having discharge port numbers 1 to 16 and 113 to 128) is a nozzle that can be simultaneously recorded at the time of print recording, and the discharge port rows 31, 32, and 33 have one end of 128 nozzles. The nozzles at the center of the nozzle row, excluding 16 parts, are nozzles that can be simultaneously recorded during print recording. In the print record B, in the ejection port arrays 31, 32, and 33 in FIG. 11A, 16 nozzles at the end of 128 nozzles (that is, a total of 32 ejection port numbers 1 to 16 and 113 to 128) are used. Nozzles) that can simultaneously record at the time of print recording, and nozzles that can simultaneously record at the time of print recording the central part of the nozzle row excluding 16 nozzles at the end of the 128 nozzles in the ejection port arrays 21, 22, and 23. I do.
[0029]
8 and 13 show a print recording method when 100% solid printing is performed. In the configuration of the present invention, when the ejection port row is 600 DPI per row and the ejection volume is 4.5 pl, 100% solid is not filled in one scan in one row of print recording. A print recording method of performing two scans at a position is shown. FIG. 8 shows the relationship between the print record and the head position, and the print record state by each scan. FIG. 13 assists the explanation of FIG. 8 and shows the ejection port numbers actually printed in each scan. As shown in FIGS. 8 and 13, each time 100 columns (the number of records at the recording resolution in the scanning direction) are printed in one scan, the print record A and the print record B are alternately recorded. By performing such a print recording method, the amount of deflection in the nozzle row direction of the 32 nozzles at the end is reduced to 9 μm from 20 μm for the comparative conventional head, and the carriage scan is performed. Connection streaks are gone. Further, by using the print recording method of the present embodiment, it is possible to print on the same raster (in the same row in the scanning direction) by another discharge port, and it is also possible to obtain a streak reduction effect by multi-pass printing. Was completed.
[0030]
In the present embodiment, the recording of the 16 ejection ports at the end portion may be other than 16 ejection ports. In this embodiment, there are two nozzle rows, but one nozzle row may be used. Further, in the present embodiment, all of the formed discharge ports are used for image formation. However, when there are discharge ports that are not used for image formation as dummy discharge ports, they are used for image formation except for dummy discharge ports. The discharge port to be used is defined as an end.
[0031]
【The invention's effect】
The present invention relates to an ink jet recording head having a plurality of discharge ports for discharging ink. Specifically, as shown in FIG. 11, in a head having a configuration suitable for reciprocal printing such as A: Cyan, B: Magenta, C: Yellow, D: Magenta, and E: Cyan,
In one main scan, the nozzles at the end of the ejection port row 21 to 23 and the nozzle at the center of the ejection port row 31 to 33 in FIG. By performing print recording, the influence of airflow is reduced.
[0032]
With such a configuration, it is possible to reduce the phenomenon that the ejection direction is bent, and to suppress the occurrence of printing streaks.
[Brief description of the drawings]
FIG. 1 is a diagram showing a print recording method.
FIG. 2 is a diagram showing ejection port numbers actually printed in scanning.
FIG. 3 is a schematic view of an ink jet recording apparatus.
FIG. 4 is a diagram showing a solid printing portion.
FIG. 5 (a) is a diagram showing an observation at the time of discharging a droplet. (B) The figure which expanded the joint.
FIG. 6 is a diagram showing a state in which a nozzle is discharged.
FIG. 7 is a diagram illustrating a relationship between a discharge droplet and a displacement amount.
FIG. 8 is a diagram showing a reduction in the amount of ejected droplets and the amount of displacement
FIG. 9 is a diagram showing ejection numbers actually printed.
FIG. 10 is a schematic view of an inkjet print head.
FIG. 11 is a view showing a substantially parallel row of ejection openings.
FIG. 12 is a diagram in which ejection port numbers are arranged.
FIG. 13 is a view showing ejection numbers actually printed.

Claims (6)

In a liquid ejection recording method for performing printing recording of the same liquid type by a plurality of ejection port arrays mounted on a liquid ejection recording head while scanning the recording medium,
At the time of one print recording scan, one discharge port row discharges liquid from one or more discharge ports at both ends of the row to perform print recording, and the discharge port row different from the discharge port row is from the discharge port at the center of the row. A liquid discharge recording method, wherein a liquid is discharged to perform print recording. In a liquid ejection recording method for performing printing recording of the same liquid type by a plurality of ejection port arrays mounted on a liquid ejection recording head while scanning the recording medium,
At the time of one print recording scan, one discharge port row 1 discharges liquid from one or more discharge ports at both ends of the row to perform print recording, and a discharge port row 2 different from the discharge port row has a discharge port at the center of the row. A print record A in which a liquid is ejected from the outlet to perform a print record,
At the time of one print recording scan, one discharge port row 1 discharges liquid from the discharge port at the center of the row to perform print recording, and the discharge port row 2 different from the discharge port row has one or more discharge port rows at both ends. A print record B in which a liquid is ejected from an ejection port to perform a print record;
Wherein the print recording is performed while alternately switching between the print record A and the print record B in the same scan. The pitch of one or more discharge ports at both ends of one discharge port array according to claim 1 and the pitch of a discharge port at a central portion excluding the discharge ports at both ends are shifted, and the discharge is performed. The pitch of one or more discharge ports at both ends of the discharge port row that discharges the same liquid type as the outlet row is different from that of the discharge port row, and the pitch with the discharge port at the center excluding the discharge ports at both ends is different. An ink jet recording method, which is different from the ejection port array. 4. An ink jet recording method according to claim 1, wherein the number of ejection ports at both ends of the row is less than 16. 4. An ink jet recording method according to claim 1, wherein the ejection volume of the liquid ejection recording head according to claim 1, 2, or 3 is 8.5 pl or less. At the time of one print recording scan, one discharge port row discharges liquid from one or more discharge ports at both ends of the row to perform print recording, and the discharge port row different from the discharge port row is from the discharge port at the center of the row. In performing print recording by discharging the liquid, the pitch of one or more discharge ports at both ends of one discharge port row and the pitch of the discharge ports at the center excluding the discharge ports at both ends are shifted, and The pitch of one or more discharge ports at both ends of the discharge port row that discharges the same liquid type as the discharge port row is different from that of the discharge port row, and the pitch of the one or more discharge ports is the same as the discharge port at the center excluding the discharge ports at both ends. An ink jet recording head having a pitch different from that of the ejection port array.

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