JP6786691B2 - Recording head and inkjet recording device - Google Patents

Description

The present invention relates to a recording head and an inkjet recording device.

Using a recording head provided with a plurality of ejection port rows having a plurality of ejection port rows in which a plurality of ejection ports for ejecting ink are arranged, the recording head is reciprocally scanned with respect to the recording medium in the forward direction and the return direction. However, an inkjet recording device that forms an image on a recording medium by ejecting ink has been conventionally known.

In an inkjet recording apparatus that performs such reciprocating scanning, there is a color difference between the area recorded by scanning in the forward direction on the recording medium and the area recorded by scanning in the backward direction on the recording medium. Is known to occur and the image quality may be deteriorated. This color difference will be described in detail focusing only on black ink and yellow ink. When a recording head having only one black ink ejection port row group and one yellow ink ejection port row group is used, ink is applied to the area recorded by one scan in the order of black and yellow. Ink is applied to the area recorded by the other scanning in the order of yellow and black. Due to such a difference in the order of applying ink between the reciprocating scans, a color difference occurs between the reciprocating recording areas.

On the other hand, in Patent Document 1, the color difference between the reciprocating recording regions described above is reduced by arranging a plurality of discharge port rows in the recording head. Specifically, in FIG. 9 of Patent Document 1, one yellow ink ejection port row group and two black ink ejection port row groups are provided, and the black ink ejection port row group and the yellow ink ejection port row group are provided. They are arranged so that they are symmetrical (symmetrical). By using such a recording head, ink can be applied in the order of black, yellow, and black in both forward scanning and rescanning, so that it is possible to reduce the color difference between the reciprocating recording areas. ..

On the other hand, in the conventional inkjet recording apparatus, a total of four colors of ink, which are the basic colors (three primary colors) of cyan, magenta, yellow ink, and black ink, are often used. However, in recent years, in addition to these four color inks, it is known that inks of different colors are further used depending on the application. For example, when cyan ink and magenta ink having low lightness are superimposed and applied on a recording medium in order to reproduce a blue hue, there is a problem that an image having a conspicuous graininess is recorded. By using light cyan ink and light magenta ink, which have almost the same hue as cyan and magenta, respectively, and have higher brightness, the above-mentioned graininess can be eliminated, but in addition to the four colors of ink, two more colors of ink are added. Since it will be used, it will lead to an increase in size and cost of the device. On the other hand, Patent Document 2 describes that an ink having a hue between cyan and magenta and having a higher brightness than cyan and magenta, so-called light blue ink, is used. By using this light blue ink, it is possible to perform recording in which the graininess in the easily visible blue hue is inconspicuous without causing an increase in size and cost of the apparatus.

Japanese Unexamined Patent Publication No. 2010-046904 JP-A-2002-154240

However, a group of ejection ports for ejecting so-called light blue ink as described in Patent Document 2 to a recording head in which the ejection port rows of inks of different colors described in Patent Document 1 are symmetrically arranged. It was found that the following problems occur when trying to arrange more.

First, consider the case where only one light blue ink ejection port row group is arranged. In view of the reduction of the color difference between the reciprocating recording regions described above, it is preferable to arrange the light blue ink ejection port row group between the two black ink ejection port row groups. With such an arrangement, it is possible to apply ink in the order of black, light blue, and black in both forward scanning and rescanning.

However, in the above arrangement, the distance between the two black ink ejection port rows is relatively long for the black ink, which is the ink having the lowest brightness among the colors. As a result, when the recording head is tilted and mounted on the recording device, or when the scanning of the recording head is tilted, the deterioration of the image quality may become noticeable.

For example, when the light blue ink ejection port row group is further arranged as described above with respect to the recording head in which the ink ejection port row group of each color is arranged in the order of black, yellow, and black disclosed in FIG. 9 of Patent Document 1. In addition to the yellow ink ejection port row group, the light blue ink ejection port row group is located between the two black ink ejection port row groups. Since the number of ejection port rows arranged between the two black ink ejection port rows is large in this way, the distance between the black ink ejection port rows is long.

On the other hand, the longer the distance between the two ejection port rows, the larger the ink landing position deviation that occurs when the recording head is tilted and mounted on the recording device or when the scanning of the recording head is tilted. Become. If the landing position shift of the ink occurs in the black ink having the lowest brightness, the deterioration of the image quality becomes larger than that in the inks of other colors. Therefore, if the light blue ink ejection port row group is arranged between the two black ink ejection port row groups and the distance between the black ink ejection port row groups having the lowest brightness is increased, the ink There is a risk that the image quality will be significantly degraded due to the displacement of the landing position.

If two light blue ink ejection port rows are provided and two black ink ejection port rows are arranged between the two light blue ink ejection port rows, black ink can be generated between reciprocating scans. The order of applying the light blue ink can be the same, and the distance between the two black ink ejection port rows can be shortened. However, although there is originally no problem with only one discharge port row group, if two discharge port row groups are provided, the recording head becomes unnecessarily large.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a recording head capable of reducing color difference between reciprocating scans and suppressing deterioration of image quality due to ink landing position shift.

Therefore, in the present invention, a plurality of recording units including a discharge port row in which a plurality of discharge ports are arranged along the first direction are provided along a second direction intersecting the first direction for recording. A recording head that records an image by moving in the second direction with respect to the medium, and is a first recording unit that ejects ink of a first color having a hue angle of h1 and a brightness of L1. And a second recording unit, a third recording unit and a fourth recording unit that eject ink of a second color having a hue angle larger than h1 and a brightness of L2, and a hue angle from h1. A fifth recording unit that ejects a third color ink that is larger and smaller than h2 and has a brightness L3 greater than either L1 or L2, and an L4 having a brightness smaller than either L1 or L2. It has a sixth recording unit and a seventh recording unit that ejects ink of a fourth color, and in the second direction, the fifth recording unit, the sixth recording unit, and the third. The recording units 7 are provided in this order between the first recording unit and the second recording unit, and the fifth recording unit, the sixth recording unit, and the seventh recording unit. Is provided between the third recording unit and the fourth recording unit, and further, the third color ink is provided on the opposite side of the sixth recording unit with the seventh recording unit in between. It is characterized in that a recording unit for discharging is not provided.

According to the recording head according to the present invention, it is possible to reduce the color difference between reciprocating scans and suppress the deterioration of image quality due to the displacement of the ink landing position.

It is a perspective view of the image recording apparatus applied in embodiment. It is a schematic diagram which shows the recording control system in embodiment. It is a figure for demonstrating the data processing process in an embodiment. It is a figure which shows the ink recording rate in each density gradation in an embodiment. It is a perspective view of the recording head applied in embodiment. It is a figure which shows the chip surface in the recording head applied in embodiment. It is a perspective view of the vicinity of the discharge port in the recording head applied in embodiment. It is a figure for demonstrating the color difference between reciprocating scans. It is a figure for demonstrating the deterioration of image quality due to the displacement of the landing position of ink. It is a figure which shows the chip surface in the recording head applied in embodiment. It is a perspective view of the vicinity of the discharge port in the recording head applied in embodiment.

The first embodiment of the present invention will be described in detail with reference to the drawings below.

(First Embodiment)
FIG. 1 is a schematic view showing the internal configuration of the inkjet recording device 1000 according to the present embodiment. Note that FIG. 1 shows a state when the upper cover is lifted.

The inkjet recording device (hereinafter, also referred to as a printer or recording device) 1000 in the present embodiment is provided with a carriage 5 that reciprocates (reciprocally scans) along the X direction (intersection direction), and the carriage 5 will be described later. The recording head 1 is mounted. In the present embodiment, the moving speed (scanning speed) of the carriage 5 and the recording head 1 is about 25 inches / sec. By ejecting ink from the recording head 1 while reciprocating the carriage 5 and the recording head 1, the image recording operation on the recording medium is performed.

The recording medium is fed from the paper feed tray of the printer and conveyed in the sub-scanning direction intersecting the X direction. The transport speed of the recording medium in this embodiment is about 5 inches / sec.

In the present embodiment, the scanning of the recording head 1 and the transfer of the recording medium as described above are alternately repeated to complete the recording on one recording medium. In this embodiment, a so-called one-pass recording method that completes recording in one scan for a unit area on a recording medium may be used, or recording is completed in a plurality of scans for a unit area. A so-called multipath recording method may be used.

Further, the thickness of the paper used in this embodiment is about 0.3 mm, and the distance in the height direction between the recording head 1 and the paper in that case is about 1.0 mm. A scanner 4 for capturing a recorded image is provided on the upper part of the printer, and the scanner 4 is integrated with the upper cover of the printer.

FIG. 2 is a block diagram showing a schematic configuration of a control system in the printer 1000 according to the present embodiment. The main control unit 300 includes a CPU 301 that executes processing operations such as calculation, selection, discrimination, and control, a ROM 302 that stores a control program or the like to be executed by the CPU 301, a RAM 303 that is used as a buffer for recorded data, and input / output. It has a port 304 and the like. In addition, a mask pattern and the like, which will be described later, are also stored in the ROM 303. The input / output ports 304 are connected to drive circuits 305, 306, 307 such as a transfer motor (LF motor) 309, a carriage motor (CR motor) 310, a recording head 1, and an actuator in a cutting device for cutting the recording medium. , 308 are connected. Further, the main control unit 300 is connected to the host computer PC 312 via the interface circuit 311.

(Data generation processing)
FIG. 3 is a flowchart of a recorded data generation process used for recording executed by the CPU 301 according to the control program in the present embodiment. This control program is stored in ROM 302 in advance.

The input image data is an 8-bit RGB signal for each color having a resolution of 600 dpi and 256 gradations per pixel. This data is first sent to the color correction processing unit 401, and is subjected to processing for associating a color space such as sRGB represented by the host PC 312 with a color space that can be represented by the printer 1000. Specifically, by referring to a three-dimensional look-up table (LUT) stored in ROM 302 in advance, an RGB 8-bit 256-value signal is also converted into an RGB 8-bit 256-value signal.

Next, the ink color separation processing unit 402 converts the data generated by the color correction unit 401 into data corresponding to the ink color used by the recording device 1000. Specifically, by referring to the three-dimensional LUT stored in the ROM 302 in advance, the RGB 8-bit 256-value signal is converted into the 8-bit density signal of each ink color.

The data decomposed into ink colors is input to the γ correction processing unit 403, and the density value is corrected for each ink color. The γ correction is a correction for making the density of the input data and the optical density of the image represented by the recording medium have a linear relationship. Specifically, the one-dimensional LUT stored in the ROM 302 in advance is referred to, and the 8-bit 256-value density data of each ink color is also converted into the 8-bit 256-value density data.

After that, the 8-bit 256-value density data corresponding to each ink color is quantized by the quantization processing unit 404, and 2-bit 4-value quantization data corresponding to each ink color is generated. In the present embodiment, the quantization processing method is not particularly limited, and a dither method, an error diffusion method, or the like can be adopted.

Next, the quantization data is sent to the index expansion processing unit 405, where it is converted into 1-bit binary data. Specifically, an index pattern is used in which the number and position of ink ejected for a total of 4 pixels of 2 pixels × 2 pixels according to the value of the quantization data for one pixel group consisting of 2 pixels × 2 pixels are used. Binary data is generated that defines the ejection or non-ejection of ink to the pixels. The index pattern is stored in ROM 302 in advance.

After that, the binary data is sent to the distribution processing unit 406, and the binary data is distributed to a plurality of scans with respect to the unit area. Specifically, a plurality of mask patterns corresponding to a plurality of scans and defining the permissible or non-permissible ink ejection for each pixel are used to generate 1-bit binary recording data used in each of the multiple scans. To do. The plurality of mask patterns are stored in the ROM 302 in advance. Further, when recording is performed by the one-pass recording method, the processing in the distribution processing unit 406 is omitted.

Further, although the mode in which the CPU 301 in the printer 1000 executes all the processes in 401 to 406 is described here, even if the CPU (not shown) in the PC 312 executes some or all the processes in 401 to 406. good.

(Ink hue and brightness)
In this embodiment, recording is performed using light blue ink in addition to cyan ink, magenta ink, yellow ink, and black ink.

The light blue ink used in the present embodiment has a hue relatively close to the blue hue reproduced when the same amount of cyan ink and magenta ink are mixed, and a relatively high brightness (low density). is there. Specifically, the light blue ink used in the present embodiment satisfies the condition that the hue is between the cyan ink and the magenta ink and the brightness is higher than that of the cyan ink and the magenta ink.

By using light blue ink that satisfies these conditions, it is possible to reproduce the blue hue without superimposing cyan ink and magenta ink when recording an image having a low density (small ink ejection amount). .. Therefore, it is possible to record an image with less graininess in the blue hue.

Hereinafter, the hue angle of cyan ink is h1, the brightness is L1, the hue angle of magenta ink is h2, the brightness is L2, the hue angle of light blue ink is h3, the brightness is L3, the hue angle of black ink is h4, and the brightness is L4. , The hue angle of the yellow ink is h5, the brightness is L5, and the hue angle and the brightness of the inks of each color used in this embodiment are shown in (Table 1).

As can be seen from (Table 1), in the light blue ink used in the present embodiment, the hue angle h3 is between the hue angle h1 of the cyan ink and the hue angle h2 of the magenta ink, and the brightness L3 is the brightness L1 of the cyan ink. It satisfies the condition that it is higher than both the brightness L2 of magenta ink and.

(How to use ink of each color)
The method of using the above-mentioned inks of each color is described below.

FIG. 4A shows the ejection amount (recording rate) of the ink of each color used for reproducing each density gradation from white to black via blue in the present embodiment, the so-called blue line.

First, in a low density region close to white, the density is increased by increasing the ejection amount of the light blue ink in order to avoid a decrease in graininess due to the superimposition of cyan ink and magenta ink. After that, when it approaches blue and reaches the intermediate density region, the density cannot be reproduced with the light blue ink. Therefore, the ejection amount of the cyan ink and the magenta ink is increased while the ejection amount of the light blue ink is decreased to increase the density. .. Then, in the high density region close to black, the density close to black is reproduced by increasing the ejection amount of black ink while decreasing the ejection amount of cyan ink or magenta ink.

Further, FIG. 4B shows the ejection amount (recording rate) of the ink of each color used for reproducing each density gradation from white to black via yellow in the present embodiment, the so-called yellow line. ..

In the low to intermediate density range from white to yellow, the amount of yellow ink ejected is increased to increase the density. In addition, when starting to move toward black from the intermediate density region, if yellow with high brightness and black with low brightness are used at the same time, the image quality may deteriorate. Therefore, while reducing the ejection amount of yellow ink, cyan ink, magenta ink, etc. Use light blue ink to increase the density. Finally, the ejection amount of black ink is increased to reproduce a density close to black.

(Recording head)
FIG. 5 is a perspective view showing a recording head used in the present embodiment.

In the recording head 1 of the present embodiment, the ink supply unit 2 and the ink ejection unit 3 are integrally configured. The ink supply unit 2 is provided with a holding body 2A that holds an ink tank (not shown) for supplying ink.

The ink ejection unit 3 is provided with a chip (Bk chip) 10 for ejecting black pigment ink and a chip (Cl chip) 20 for ejecting dye ink, which will be described later. In the following description, the Cl chip 20 will be focused on.

FIG. 6 is an enlarged view of the Cl chip 20 in the recording head 1 in the present embodiment. Further, FIG. 7 is a diagram for explaining the internal configuration of each discharge port row group in the present embodiment.

A total of eight common liquid chambers 21 connected to the ink supply unit 2 are formed in the Cl chip 20 of the present embodiment, and one ejection port row group LG1 is formed in one common liquid chamber 21. There is. Each discharge port row group LG1 is composed of a plurality of discharge port rows, and the diameters of the discharge ports (discharge port diameters) arranged in the discharge port rows are different for each discharge port row group.

Each discharge port in the Cl chip 20 is open to a nozzle plate connected to a member forming the common liquid chamber 21 (hereinafter, also referred to as a common liquid chamber forming member). An electric heat conversion element (hereinafter, also referred to as a heater) is arranged at a position facing each discharge port in the common liquid chamber forming member.

Each discharge port row group LG1 in the Cl chip 20 will be described in detail below.

1. 1. Yellow Ink Discharge Port Row Group The Cl chip 20 in the present embodiment is provided with only one yellow ink discharge port row group (LG1 (Y)). The yellow ink ejection port row group LG1 (Y) is composed of two ejection port rows.

FIG. 7A is a diagram showing details of the yellow ink ejection port row group LG1 (Y).

In the yellow ink discharge port row group LG1 (Y), the discharge ports 22 having a diameter of about 16 μm and a relatively large ink droplet size of about 5 pl are provided on both sides of the common liquid chamber 21. Two rows of discharge ports are provided. In each of these discharge port rows, 264 discharge ports 22 are arranged in the Y direction at intervals of 600 dpi (about 42.3 μm). Further, these discharge port rows are arranged so as to be spaced apart from each other by 1200 dpi (about 21.2 μm) in the Y direction.

Further, as described above, the heater 28 is provided at a position facing the discharge port 22. Further, the foam chamber 25 is provided so as to surround the heater 28, and the ink flow path 26 is provided so as to connect between the foam chamber 25 and the common liquid chamber 21. Further, a foreign matter blocking column 27 is provided to prevent foreign matter in the ink from entering the ink flow path 26. Since the configurations of the heater 28, the foam chamber 25, the ink flow path 26, and the foreign matter obstructing column 27 are the same in the other discharge port row groups, the description thereof will be omitted below.

2. Black ink, cyan ink, and magenta ink ejection port rows The Cl chip 20 in the present embodiment is provided with two black ink ejection port rows (LG1 (K1) and LG1 (K2)). The black ink ejection port row groups LG1 (K1) and LG1 (K2) are each composed of two ejection port rows.

FIG. 7B is a diagram showing details of the black ink ejection port row group LG1 (K1).

In the black ink ejection port row group LG1 (K1), the diameter of the ejection port on one side (left side) of the common liquid chamber 21 is about 16 μm, and the size of the ink droplets ejected is relatively large, about 5 pl. One discharge port row having a discharge port 22 is provided. Further, on the other side (right side) of the common liquid chamber 21, there is one discharge port row having a discharge port diameter of about 12 μm and a medium discharge port 24 having a size of about 2 pl of ink droplets to be discharged. It is provided. In these discharge port rows, 264 discharge ports 22 and 24 are arranged in the Y direction at intervals of 600 dpi (about 42.3 μm), respectively. Further, these discharge port rows are arranged so as to be spaced apart from each other by 1200 dpi (about 21.2 μm) in the Y direction.

The black ink discharge port row group LG1 (K2) also has a discharge port row having a diameter of about 16 μm and a discharge port row having a diameter of about 12 μm, similarly to the discharge port row group LG1 (K1). have. However, the two discharge port rows LG1 (K1) and LG1 (K2) are different in that the arrangement of the two discharge port rows arranged in each in the X direction is reversed. Further, the two discharge port rows having the same diameter in the discharge port rows LG1 (K1) and LG1 (K2) are positioned so as to be separated from each other by an interval of 1200 dpi (about 21.2 μm) in the Y direction. It is provided as follows.

The cyan ink ejection port row group LG1 (C1) and the magenta ink ejection port row LG1 (M1) each have the same configuration as the black ink ejection port row group LG1 (K1). Further, the cyan ink ejection port row group LG1 (C2) and the magenta ink ejection port row LG1 (M2) each have the same configuration as the black ink ejection port row group LG1 (K2).

3. 3. Light blue ink ejection port row group The Cl chip 20 in the present embodiment is provided with one light blue ink ejection port row group (LG1 (LB)). The light blue ink ejection port row group LG1 (LB) is composed of four ejection port rows.

FIG. 7C is a diagram showing details of the light blue ink ejection port row group LG1 (LB).

As shown in FIG. 7C, in the light blue ink discharge port row group LG1 (LB), two discharge port rows are provided on one side (left side) of the common liquid chamber 21. One is a discharge port row having a discharge port diameter of about 12 μm and a medium discharge port 24 having a size of about 2 pl of ink droplets to be discharged, which is provided at a position closer to the common liquid chamber 21. ing. The other is a discharge port row having a discharge port 23 having a diameter of a discharge port of about 9 μm and a relatively small size of ink droplets of about 1 pl, which is provided at a position far from the common liquid chamber 21. ing. The same applies to the other side (right side) of the common liquid chamber 21, and two discharge port rows having a discharge port diameter of about 12 μm and a discharge port row having a discharge port diameter of about 9 μm are provided. As described above, in the light blue ink discharge port row group, there are two discharge port rows having a discharge port diameter of about 12 μm and two discharge port rows having a discharge port diameter of about 9 μm, for a total of four discharge port rows. Is provided.

In these discharge port rows, 264 discharge ports 23 and 24 are arranged in the Y direction at intervals of 600 dpi (about 42.3 μm), respectively. Further, the two discharge port rows (the discharge port row having a discharge port diameter of about 16 μm and the discharge port row having a discharge port diameter of about 12 μm) located on the same side with respect to the common liquid chamber 21 are 1200 dpi in the Y direction. They are arranged at intervals of (about 10.6 μm).

4. Arrangement order of ejection port rows in the chip As shown in FIG. 6, the chip 20 in the present embodiment has cyan ink ejection port row group LG1 (C1) and magenta ink ejection port row group LG1 (M1) from the left side. , Light blue ink ejection port row group LG1 (LB), black ink ejection port row group LG1 (K1), yellow ink ejection port row group LG1 (Y), black ink ejection port row group LG1 (K2), Each ejection port row group is arranged in the order of the magenta ink ejection port row group LG1 (M2) and the cyan ink ejection port row group LG1 (C2).

The reason for the arrangement order of each discharge port row group will be described.

In the present embodiment, the arrangement order of each ejection port row group is determined in consideration of the two points of reducing the color difference between the reciprocating scans and suppressing the deterioration of the image quality due to the displacement of the ink landing position. First, the color difference between the reciprocating scans and the image quality deterioration due to the ink landing position shift will be described.

(1) Color difference between reciprocating scans Fig. 8 (a) shows two discharge port rows: the discharge port row group LG (Color1) of Color1 and the discharge port row group LG (Color2) of Color2 having a color different from Color1. It is a figure which shows the recording head which consists of a group. Further, FIG. 8B is a diagram for explaining a state after landing of ink droplets when recording is performed by reciprocating scanning using the recording head of FIG. 8A.

When the recording head shown in FIG. 8A is used, ink is ejected in the order of Color2 and Color1 in the forward scanning and in the order of Color1 and Color2 in the rescanning for the same position on the recording medium in the scanning direction. Ink is ejected.

Here, if the amount of ink ejected from Color1 and Color2 is small and the inks from Color1 and Color2 are not ejected to the same region on the recording medium P, Color1 is as shown in FIG. 8B. Dot 33 and Dot 34 of Color2 do not overlap. Therefore, even if the ink application order is different between the forward scan and the reverse scan, the appearance of the dots after landing is the same, so that the reproduced colors are almost the same.

However, when the amount of ink ejected from Color1 and Color2 is large and the inks from Color1 and Color2 are ejected to the same region, the colors reproduced in the forward scan and the rescan are different. As shown in FIG. 8B, in the forward scan, the color 2 ink is applied onto the recording medium to form the dots 34, and then the color 1 ink is applied onto the dots 34. Since the dye ink wraps around the previously formed dots and is fixed, the dots 33 of Color 1 are formed in the lower layer of the dots 34 of Color 2. Therefore, at the time of forward scanning, an image in which Color2, which is the color of dots 34 formed on the upper layer on the recording medium, is dominant is recorded. On the other hand, during the rescanning, the ink is applied in the order of Color1 and Color2, so that the dots 33 of Color1 are formed in the upper layer, so that Color1 becomes the dominant color.

As described above, when the amount of ink ejected is large, Color 2 becomes the dominant color in the forward scanning and Color 1 becomes the dominant color in the rescanning. This dominant color difference causes a color difference between reciprocating scans.

(2) Image quality deterioration due to ink landing position deviation When the recording head is mounted at an angle with respect to the recording device or when the scanning of the recording head is inclined, the longer the distance between the ejection port rows, the more of them. The landing position of the ink ejected from the ejection port row group shifts.

FIG. 9A shows a recording head having two ejection port rows LG (1), LG (2), and LG (3) for ejecting inks of different colors, and the above-mentioned inclination does not occur. It is a schematic diagram for demonstrating the landing position of the ink from each discharge port row group LG (1), LG (2), LG (3) of the case. Further, FIG. 9B shows the ink landing positions from the respective ejection port row groups LG (1), LG (2), and LG (3) when the above-mentioned inclination occurs in the recording head of FIG. 9A. It is a schematic diagram for demonstrating.

In FIG. 9, the two discharge port row groups LG (2) are between the two discharge port row groups LG (1), and the two discharge port row groups LG (2) are between the two discharge port row groups LG (2). A recording head in which each discharge port row group is arranged in the X direction so that (3) is located is shown. In other words, the distance between the discharge port row group LG (1) is the longest, and the distance between the discharge port row group LG (3) is the shortest.

Further, in FIG. 9, the ink landing position from the ejection port row group LG (1) is 30, the ink landing position from the ejection port row group LG (2) is 31, and the ink from the ejection port row group LG (3). The landing position of is shown in 32 respectively. Here, among a plurality of discharge ports arranged in the Y direction for each of the discharge port row groups LG (1), LG (2), and LG (3), the discharge ports 8 are composed of ruled lines or black-painted discharge ports. The landing position of the ink ejected from the ejection port row is described.

As shown in FIG. 9A, if no inclination has occurred, the two discharge port row groups LG (1), the two discharge port row group LG (2), and the two discharge port row group LG (3). In any of the above, the ink droplets land at the same interval as the arrangement interval of the ejection port. Therefore, the landing position of the ink is the same regardless of the distance between the ejection port rows.

On the other hand, when the inclination is generated as shown in FIG. 9B, the degree of the ink landing position deviation in the Y direction differs depending on the distance between the ejection port rows. For example, with respect to the ejection port row group LG (3) in which the distance between the ejection port row groups is relatively short, when the inclination occurs, the ink landing position shifts as shown in 32 of FIG. 9B, but FIG. 9 ( As can be seen from the comparison with 32 of a), it is not so large. However, in the ejection port row group LG (1) in which the distance between the ejection port row groups is relatively long, the ink landing position shift when the inclination occurs as shown in FIG. 9 (b) 30 is shown in FIG. 9 (b). It will be larger than 30 in a).

As described above, the longer the distance between the ejection port rows, the greater the degree of deviation of the ink landing position when the ink is tilted, which greatly affects the deterioration of image quality.

In consideration of the above (1) color difference between reciprocating scans and (2) deterioration of image quality due to ink landing position deviation, the arrangement order of the ejection port rows in the present embodiment is determined.

First, in order to reduce the color difference between the reciprocating scans described in (1), the cyan ink ejection port row group LG1 (C1), LG1 (C2), and magenta ink ejection port row group in the chip 20 shown in FIG. LG1 (M1), LG1 (M2), yellow ink discharge port row group LG1 (Y), black ink discharge port row group LG1 (K1), LG1 (K2) are each discharge ports so as to be symmetrical. The columns are arranged.

Specifically, two magenta ink ejection port rows LG1 (M1) and LG1 (M2) are arranged inside the two cyan ink ejection port rows LG1 (C1) and LG1 (C2). Further, two black ink ejection port rows LG1 (K1) and LG1 (K2) are arranged inside the two magenta ink ejection port rows LG1 (M1) and LG1 (M2). Further, one yellow ink ejection port row group LG1 (Y) is arranged inside the two black ink ejection port row groups LG1 (K1) and LG1 (K2).

Therefore, for cyan ink, magenta ink, yellow ink, and black ink, the order of applying ink can be made equal in forward scanning and rescanning. In other words, since ink can be applied in the order of cyan, magenta, black, yellow, black, magenta, and cyan in either of the reciprocating scans, cyan ink, magenta ink, yellow ink, and black ink can be applied between reciprocating scans. It is possible to reduce the color difference.

On the other hand, as can be seen from FIG. 6, the light blue ink ejection port row group LG1 (LB) includes the cyan ink ejection port row group LG1 (C1), LG1 (C2) and the magenta ink ejection port row group LG1 ( It is arranged so as to be a target system for M1) and LG1 (M2), but it is a non-target system for the black ink ejection port row groups LG1 (K1) and LG1 (K2). Have been placed.

Specifically, the light blue ink ejection port row group LG1 (LB) is inside the two cyan ink ejection port rows LG1 (C1) and LG1 (C2), and the two magenta ink ejection port rows It is arranged at a position inside the groups LG1 (M1) and LG1 (M2). Therefore, for example, focusing on light blue ink and cyan ink, the ink can be ejected in the order of cyan, light blue, and cyan in both reciprocating scanning. Therefore, for light blue ink and cyan ink, or light blue ink and magenta ink, the color difference between reciprocating scans can be reduced.

On the other hand, the light blue ink ejection port row group LG1 (LB) is arranged outside the two black ink ejection port row groups LG1 (K1) and LG1 (K2). In other words, focusing only on the light blue ink and the black ink, from the left side, the light blue ink ejection port row group LG1 (LB), the black ink ejection port row group LG1 (K1), and the black ink ejection port row group LG1 ( They are arranged in the order of K2). Therefore, ink is ejected in the order of black, black, and light blue in the forward scanning and ink is ejected in the order of light blue, black, and black in the rescanning at the same position in the X direction on the recording medium. .. Therefore, when the discharge amount of the light blue ink and the black ink is large, there is a possibility that a color difference may occur between the reciprocating scanning between the light blue ink and the black ink.

However, as described with reference to FIG. 4, in the present embodiment, the recording rate (ejection amount) of the inks of each color is determined so that the light blue ink and the black ink are not ejected at the same time. In other words, there are few colors that can be reproduced using both light blue ink and black ink in this embodiment.

For example, as shown in FIG. 4A, light blue ink is used at low to intermediate densities on the blue line, but black ink is rarely used. In addition, black ink is used at intermediate to high concentrations, but light blue ink is not used.

Further, as shown in FIG. 4B, although both the light blue ink and the black ink may be used at high density on the yellow line, the ejection amount is small.

As described above, in the present embodiment, a large amount of light blue ink and black ink are not discharged to the same region. Therefore, the overlap of the dots of the light blue ink and the black ink as described with reference to FIG. 8B is extremely small. Therefore, even if the light blue ink ejection port row group LG1 (LB) is arranged so as to be asymmetrical with respect to the black ink ejection port row group LG1 (K1) and LG1 (K2), the light blue ink and the light blue ink are used. Color differences between the reciprocating scans of black ink are unlikely to actually occur.

On the other hand, as can be seen from FIG. 4A, light blue ink and cyan ink may be used in a large amount at the same time at an intermediate density or the like on the blue line. In other words, there are many colors that can be reproduced using both light blue ink and cyan ink in this embodiment.

Therefore, since a color difference may occur between the reciprocating scanning between the light blue ink and the cyan ink, the light blue ink ejection port row group LG1 (LB) is the cyan ink ejection port row group LG1 (C1), LG1 (C2). Arrange so that the system is symmetrical with respect to. The same applies to light blue ink and magenta ink.

Here, if only the reduction of the color difference between the reciprocating scans described in (1) is considered, as shown in FIG. 6, the light blue ink ejection port row group LG1 (LB) has two black ink ejection port rows. The arrangement does not have to be asymmetric with respect to the groups LG1 (K1) and LG1 (K2). In other words, even if the light blue ink ejection port row group LG1 (LB) is arranged symmetrically with the two black ink ejection port row groups LG1 (K1) and LG1 (K2), that is, inside the book. Similar to the embodiment, no color difference between the light blue ink and the black ink occurs between the reciprocating scans.

However, if the light blue ink ejection port row group LG1 (LB) is arranged inside the two black ink ejection port row groups LG1 (K1) and LG1 (K2), the light blue ink ejection port row LG1 The distance between the two black ink ejection port rows LG1 (K1) and LG1 (K2) becomes longer by the amount of (LB). Therefore, as described in (2), the landing position shift of the black ink generated can be large. As shown in (Table 1), since black ink has the lowest brightness and is easily visible, the image quality deteriorates significantly when the landing position shift occurs.

In view of this point, in the present embodiment, the light blue ink ejection port row group LG1 (LB) is arranged outside the two black ink ejection port row groups LG1 (K1) and LG1 (K2). As a result, the distance between the black ink ejection port rows LG1 (K1) and LG1 (K2) is shortened. According to this configuration, the landing position shift of the black ink, which is easily visible, can be made small to some extent, and the deterioration of the image quality can be suppressed. As described above, since the light blue ink and the black ink are rarely used at the same time, even if they are arranged in this way, the color difference between the light blue ink and the black ink does not occur between the reciprocating scans.

According to this configuration, it is possible to perform recording while suppressing a deterioration in image quality due to an ink landing position shift while reducing a color difference between reciprocating scans.

In the first embodiment described above, the two magenta ink ejection port rows LG1 (M1) and LG1 (M2) are inside the two cyan ink ejection port rows LG1 (C1) and LG1 (C2). Although the form in which is arranged is described, other forms can also be implemented. The two black ink ejection port rows LG1 (K1) and LG1 (K2) are inside the two cyan ink ejection port rows LG1 (C1) and LG1 (C2), and the two magenta ink ejection ports The light blue ink ejection port row group LG1 (LB) is arranged at a position inside the row group LG1 (M1) and LG1 (M2), and the light blue ink ejection port row group LG1 (LB) is two cyan ink ejection port row group LG1 (C1). , Inside LG1 (C2) and inside two magenta ink ejection port rows LG1 (M1) and LG1 (M2), two black ink ejection port rows LG1 (K1), LG1 If it is arranged at a position outside (K2), the effect of this embodiment can be obtained. For example, from the left side, cyan ink ejection port row group LG1 (C1), magenta ink ejection port row group LG1 (M1), light blue ink ejection port row group LG1 (LB), and black ink ejection port row group LG1 ( K1), yellow ink ejection port row group LG1 (Y), black ink ejection port row group LG1 (K2), magenta ink ejection port row group LG1 (M2), cyan ink ejection port row group LG1 (C2) It may be arranged in the order of. Even in this case, in the relationship between the light blue ink and the cyan ink and the light blue ink and the magenta ink, which can increase the ejection amount at the same time, the color difference between the reciprocating scans can be reduced, and the two black inks Since the distance between the ejection port row groups LG1 (K1) and LG1 (K2) can be shortened, the ink landing position shift can be suppressed. However, two magenta ink ejection port rows LG1 (M1) and LG1 (M2) are arranged inside the two cyan ink ejection port rows LG1 (C1) and LG1 (C2), or two magenta ink ejection ports are arranged. When two cyan ink ejection port rows LG1 (C1) and LG1 (C2) are arranged inside the ink ejection port rows LG1 (M1) and LG1 (M2), the cyan ink and magenta ink are arranged. It is more preferable because the color difference between reciprocating scans can be further reduced.

(Second Embodiment)
In the first embodiment described above, the cyan ink discharge port row group and the magenta ink discharge port row group are composed of a discharge port row having a large discharge port diameter and a discharge port row having a medium discharge port diameter, respectively. Described.

On the other hand, in the present embodiment, the cyan ink and magenta ink discharge port rows are the discharge port rows having a large discharge port diameter, the discharge port rows having a medium discharge port diameter, and the discharge port rows having a small discharge port diameter, respectively. A form composed of a total of three discharge port rows will be described.

The description of the same part as that of the first embodiment described above will be omitted.

FIG. 10 is an enlarged view of the Cl chip 20 in the recording head 1 in the present embodiment. Further, FIG. 9 is a diagram for explaining the internal configuration of the cyan ink ejection port row group in the present embodiment.

As can be seen by comparing the Cl chip shown in FIG. 8 used in the present embodiment with the Cl chip shown in FIG. 5 used in the first embodiment, the Cl chips in the present embodiment are arranged in the arrangement order of each discharge port row group and. The first embodiment describes the configurations of the light blue ink ejection port row group LG2 (LB), the black ink ejection port row group LG2 (K1), LG2 (K2), and the yellow ink ejection port row group LG2 (Y). It is the same as the Cl chip in.

In the Cl chip used in this embodiment, each of the cyan ink ejection port row groups LG2 (C1) and LG2 (C2) and the magenta ink ejection port row group LG2 (M1) and LG2 (M2) has a large ejection port. It is used in the first embodiment in that it further includes a discharge port row consisting of outlets 22, a discharge port row consisting of discharge ports 24 having a medium discharge port diameter, and a discharge port row consisting of a discharge port 23 having a small discharge port diameter. It is different from the Cl chip.

The details will be described below.

1. 1. Cyan ink and magenta ink ejection port rows The Cl chip 20 in the present embodiment is provided with two cyan ink ejection port rows (LG2 (C1) and LG2 (C2)). Each of these cyan ink ejection port rows LG2 (C1) and LG2 (C2) is composed of three ejection port rows.

As shown in FIG. 11, in the cyan ink ejection port row group LG2 (C1), the diameter of the ejection port on one side (left side) of the common liquid chamber 21 is about 16 μm, and the size of the ink droplets ejected. Is provided with one discharge port row having a relatively large discharge port 22 of about 5 pl. On the other hand, two discharge port rows are provided on the other side (right side) of the common liquid chamber 21. One is a discharge port row having a discharge port diameter of about 12 μm and a medium discharge port 24 having a size of about 2 pl of ink droplets to be discharged, which is provided at a position closer to the common liquid chamber 21. ing. The other is a discharge port row having a discharge port 23 having a diameter of a discharge port of about 9 μm and a relatively small size of ink droplets of about 1 pl, which is provided at a position far from the common liquid chamber 21. ing.

In these discharge port rows, 264 discharge ports 22, 23, and 24 are arranged in the Y direction at intervals of 600 dpi (about 42.3 μm), respectively. Further, the discharge port row consisting of the discharge port 22 having a discharge port diameter of about 16 μm and the discharge port row consisting of the discharge port 24 having a discharge port diameter of about 12 μm are displaced by an interval of 2400 dpi (about 10.6 μm) in the Y direction. Is arranged. Further, the discharge port row consisting of the discharge port 24 having a discharge port diameter of about 12 μm and the discharge port row consisting of the discharge port 23 having a discharge port diameter of about 9 μm are displaced by an interval of 1200 dpi (about 21.2 μm) in the Y direction. Is arranged.

By ejecting cyan ink droplets of three different sizes of 5pl, 2pl, and 1pl in this way, it is possible to make the graininess inconspicuous in a wide range of density gradations. In the first embodiment, only two sizes of ink, 5pl and 2pl, could be ejected. Therefore, even when reproducing a low density, 2pl of cyan ink droplets must be used, and the formed dots are not so small. Therefore, there is a risk that a grainy feeling may be visually recognized. However, in the present embodiment, when reproducing a low density, 1 pl of cyan ink droplets can be used, so that the size of the dots becomes small and the graininess can be made inconspicuous.

Similarly to the discharge port row group LG2 (C1), the cyan ink discharge port row group LG2 (C2) also has a discharge port row having a discharge port diameter of about 16 μm and a discharge port row having a discharge port diameter of about 12 μm. Although it has a discharge port row having a discharge port diameter of about 9 μm, the two discharge port rows LG2 (C1) and LG2 (C2) are in the X direction of the three discharge port rows arranged respectively. The difference is that the arrangement is reversed. Further, the two discharge port rows having the same diameter in the discharge port row groups LG2 (C1) and LG2 (C2) are provided so as to be displaced by 1200 dpi (about 21.2 μm) in the Y direction. Has been done.

Further, the magenta ink ejection port row group LG2 (M1) is the cyan ink ejection port row group LG2 (C1), and the magenta ink ejection port row group LG2 (M2) is the cyan ink ejection port row group LG2 (C2). And each has the same configuration.

2. Arrangement order of ejection port rows in the chip As shown in FIG. 10, the chip 20 in the present embodiment has cyan ink ejection port row group LG2 (C1) and magenta ink ejection port row group LG2 (M1) from the left side. , Light blue ink ejection port row group LG2 (LB), black ink ejection port row group LG2 (K1), yellow ink ejection port row group LG2 (Y), black ink ejection port row group LG2 (K2), Each ejection port row group is arranged in the order of the magenta ink ejection port row group LG2 (M2) and the cyan ink ejection port row group LG2 (C2).

That is, as in the first embodiment, in this embodiment as well, the two black ink ejection port rows LG2 (K1) and LG2 (K2) are the two cyan ink ejection port rows LG2 (C1) and LG2. It is arranged at a position inside (C2) and inside two magenta ink ejection port rows LG2 (M1) and LG2 (M2). Further, the light blue ink ejection port row group LG2 (LB) is inside the two cyan ink ejection port row groups LG2 (C1) and LG2 (C2), and the two magenta ink ejection port row groups LG2 ( It is arranged at a position inside M1) and LG2 (M2) and outside the two black ink ejection port rows LG2 (K1) and LG2 (K2).

Therefore, in the present embodiment as well, the color difference between the reciprocating scans can be reduced in the relationship between the light blue ink and the cyan ink and the light blue ink and the magenta ink, which can increase the discharge amount at the same time. Further, since the distance between the two black ink ejection port rows LG2 (K1) and LG2 (K2) can be shortened, deterioration of image quality due to a large displacement of the landing position of low-brightness ink can be suppressed. It will be possible.

In each of the embodiments described above, the hue angle h3 of the light blue ink is between the hue angle h1 of the cyan ink and the hue angle h2 of the magenta ink, and the light blue ink brightness L3 is the cyan ink brightness L1. An ink satisfying the condition that the lightness is higher than both the magenta ink and the magenta ink L2 was used as the light blue ink. However, as a result of the examination by the inventors, when the same amount of cyan ink and magenta ink are mixed, the hue angle of blue color is h'and the surface brightness of the recording medium used is L'. It was found that it is more preferable to satisfy the conditions of 1), (Equation 2), and (Equation 3).
(Equation 1)
h1 + (h'-h1) / 2 <h3 <h2- (h2-h') / 2
(Equation 2)
L'-L3> L3-L1
(Equation 3)
L'-L1> L2-L1

In order to preferably reproduce the blue hue with the light blue ink, it is preferable that the hue of the light blue ink is not too close to the hue of the cyan ink or the hue of the magenta ink, but is as close as possible to the hue of the blue ink.

Here, h'-h1 corresponds to the difference between the hue angle of blue and the hue angle of cyan. Therefore, the term h1 + (h'−h1) / 2 in (Equation 1) corresponds to a hue shifted from the hue of cyan to the hue side of blue by half the difference between the hue angles of blue and cyan. In other words, the term h1 + (h'-h1) / 2 in (Equation 1) corresponds to an intermediate hue between the cyan hue and the blue hue.

Further, h2-h'corresponds to the difference between the hue angle of magenta and the hue angle of blue. Therefore, the term h2- (h2-h') / 2 in (Equation 1) corresponds to a hue shifted from the hue of magenta to the hue side of blue by half the difference between the hue angles of magenta and blue. In other words, the term h2- (h2-h') / 2 in (Equation 1) corresponds to a hue intermediate between the magenta hue and the blue hue.

Therefore, when the hue angle h3 of the light blue ink satisfies (Equation 1), it means that the hue of the light blue ink is located between the intermediate hues of cyan and blue to the intermediate hues of magenta and blue.

Further, as shown in FIG. 4A, in each embodiment, the blue hue is reproduced by light blue ink at low density to intermediate density, and by cyan ink and magenta ink at intermediate density to high density.

Here, if the lightness of the light blue ink is too high, the lightness of the light blue ink and the lightness of the cyan and magenta inks are separated. As a result, when cyan or magenta ink is applied onto the light blue ink, the graininess of the cyan or magenta ink may become conspicuous. Therefore, it is preferable that the brightness of the light blue ink is closer to the brightness of cyan or magenta ink than the brightness of the surface of the recording medium.

The term L'-L3 of (Equation 2) corresponds to the difference in brightness between the recording medium and the light blue ink, and the term L3-L1 corresponds to the difference in brightness between the light blue ink and the cyan ink. Therefore, when the brightness L3 of the light blue ink satisfies (Equation 2), the brightness difference between the recording medium and the light blue ink is larger than the brightness difference between the light blue ink and the cyan ink, that is, the brightness of the light blue ink is the surface of the recording medium. It means that it is closer to the brightness of cyan ink than the brightness of.

Further, the term L3-L2 of (Equation 3) corresponds to the difference in brightness between the light blue ink and the magenta ink. Therefore, when the brightness L3 of the light blue ink satisfies (Equation 3), the brightness difference between the recording medium and the light blue ink is larger than the brightness difference between the light blue ink and the magenta ink, that is, the brightness of the light blue ink is the surface of the recording medium. It means that it is closer to the lightness of magenta ink than the lightness of.

Further, in each of the above-described embodiments, there is almost no color reproduced using both light blue ink and black ink, and there is a color reproduced using both light blue ink and cyan ink and light blue ink. Although many forms of color to be reproduced using both magenta inks have been described, other forms are also possible. The number of colors reproduced using both light blue and black inks is less than the number of colors reproduced using both light blue and cyan inks, and both light blue and magenta inks. If the condition that the number of colors is less than the number of colors to be reproduced by using is satisfied, the effect can be obtained by adopting the same configuration as that of the present embodiment. If the above conditions are met, color differences between light blue ink and black ink are less likely to occur between reciprocating scans than between light blue ink and cyan ink or between light blue ink and magenta ink. is there.

Further, in each of the above-described embodiments, although each discharge port row group is composed of a plurality of discharge port rows, the discharge port row group may be composed of only one discharge port row. .. For example, all the ejection port rows may be composed of only one ejection port row consisting of ejection ports for ejecting 5 pl of ink droplets.

However, in the discharge port row group having two or more discharge port rows having a large discharge port diameter, for example, the yellow ink discharge port row group LG1 (Y) shown in FIG. 6, a large amount of ink droplets having a large size of 5 pl is discharged. Therefore, there is a possibility that a strong airflow may be generated in the vicinity of the discharge port row group. Then, when a discharge port row group having a discharge port row having a small discharge port diameter at a position adjacent to the discharge port row group, for example, a light blue ink discharge port row group LG1 (LB) shown in FIG. 6 is provided. Since ink droplets having a size as small as 1 pl are strongly affected by the air flow, the ink landing position may shift in the ejection port row having a small ejection port diameter, and the image quality may deteriorate.

However, according to the arrangement of each discharge port row group in the first and second embodiments, the discharge port row group LG1 (Y) is not adjacent to the discharge port row group LG1 (LB) as shown in FIG. Since the discharge port row group LG1 (K1) is provided between them, the deterioration of image quality due to the above-mentioned air flow can be suppressed. This is because the discharge port row group LG1 (K1) has only one discharge port row having a large discharge port diameter, so that strong airflow is unlikely to occur in the vicinity and the discharge port row has a small discharge port diameter. Therefore, even if a strong airflow is generated by the ejection from the ejection port row group LG1 (Y), the ink droplets ejected from the ejection port row group LG1 (K1) are not easily affected by the airflow.

LG1 (C1), LG1 (C2) Cyan ink ejection port group LG1 (M1), LG1 (M2) Magenta ink ejection port row group LG1 (K1), LG1 (K2) Black ink ejection port row group LG1 ( LB) Light blue ink discharge port row group

Claims (17)

A plurality of recording units including a discharge port row in which a plurality of discharge ports are arranged along the first direction are provided along a second direction intersecting the first direction, and the first A recording head that records an image by moving in two directions.
A first recording unit and a second recording unit that eject ink of a first color having a hue angle of h1 and a brightness of L1 and
A third recording unit and a fourth recording unit that eject ink of a second color having a hue angle of h2 larger than h1 and a brightness of L2, and
A fifth recording unit that ejects ink of a third color, which has a hue angle of h3 larger than h1 and smaller than h2, and a brightness of L3 larger than either L1 or L2.
A sixth recording unit and a seventh recording unit that eject ink of a fourth color whose brightness is L4, which is smaller than either L1 or L2.
Have,
In the second direction, the fifth recording unit, the sixth recording unit, and the seventh recording unit are provided between the first recording unit and the second recording unit in this order. ,
Moreover, the fifth recording unit, the sixth recording unit, and the seventh recording unit are provided between the third recording unit and the fourth recording unit.
Further, the recording head is characterized in that the recording unit for ejecting the ink of the third color is not provided on the opposite side of the sixth recording unit with the seventh recording unit interposed therebetween. When the hue angle of the color reproduced by mixing the ink of the first color and the ink of the second color in the same amount with each other is h',
h1 + (h'-h1) / 2 <h3 <h2- (h2-h') / 2
The recording head according to claim 1, wherein the recording head satisfies. About the color brightness L'on the surface of the recording medium
L'-L3> L3-L1 and L'-L1> L2-L1
The recording head according to claim 1 or 2, wherein the recording head satisfies. The recording head according to any one of claims 1 to 3, wherein the first color is cyan and the second color is magenta. The recording head according to any one of claims 1 to 4, wherein the third color is light blue. The recording head according to any one of claims 1 to 5, wherein the fourth color is black. Claim 1 is characterized in that, in the second direction, the third recording unit and the fourth recording unit are provided between the first recording unit and the second recording unit. 6. The recording head according to any one of 6. Claim 1 is characterized in that, in the second direction, the first recording unit and the second recording unit are provided between the third recording unit and the fourth recording unit. 6. The recording head according to any one of 6. Further having an eighth recording unit including an ejection port row for ejecting a fifth color ink of h5 having a hue angle smaller than h1 and L5 having a brightness greater than L4.
Any one of claims 1 to 8, wherein in the second direction, the eighth recording unit is provided between the sixth recording unit and the seventh recording unit. The recording head described in. The recording head according to claim 9, wherein the fifth color is yellow. The first recording unit, the second recording unit, the third recording unit, the fourth recording unit, the fifth recording unit, the sixth recording unit, the seventh recording unit, and the above. In addition to the eighth recording unit, ink of any one of the first color, the second color, the third color, the fourth color, and the fifth color is ejected. The recording head according to claim 9 or 10, wherein the recording unit is not provided. The eighth recording unit is provided with two rows of discharge ports having a first diameter of discharge, and is not provided with rows of discharge ports having a diameter smaller than that of the first diameter.
Each of the sixth recording unit and the seventh recording unit is provided with a discharge port row having a second diameter whose discharge port diameter is smaller than the first diameter, and the discharge port diameter is the second diameter. There is no outlet row with a smaller diameter than
The fifth recording unit is provided with a discharge port row having a third diameter whose discharge diameter is smaller than that of the second diameter.
Each of the first recording unit, the second recording unit, the third recording unit, and the fourth recording unit is provided with a discharge port row having a discharge port diameter of the third diameter. The recording head according to any one of claims 9 to 11. Each of the first recording unit, the second recording unit, the third recording unit, and the fourth recording unit has a discharge port row having a discharge port diameter of the third diameter and a discharge port diameter. However, only three rows of discharge port rows are provided, one is a row of discharge ports having the second diameter and the other is a row of discharge ports having a discharge port diameter of the first diameter.
The fifth recording unit has only four rows of discharge ports: a two-row discharge port row having a discharge port diameter of the third diameter and a two-row discharge port row having a discharge port diameter of the second diameter. Is provided,
Each of the sixth recording unit and the seventh recording unit has a discharge port row having a discharge port diameter of the second diameter and a discharge port row having a discharge port diameter of the first diameter. Only two rows of outlets, ,, are provided,
The recording head according to claim 12, wherein the eighth recording unit is provided with only two rows of discharge ports having a discharge port diameter of the first diameter. The first recording unit, the second recording unit, the third recording unit, the fourth recording unit, the fifth recording unit, the sixth recording unit, and the seventh recording unit The recording head according to any one of claims 1 to 13, wherein the recording head is provided on one chip. The number of colors reproduced using both the third color ink and the fourth color ink is the number of colors reproduced using both the first color ink and the third color ink. Claim 1 characterized in that it is less than the number of colors reproduced and less than the number of colors reproduced using both the ink of the second color and the ink of the third color. The recording head according to any one of 14 to 14. A first recording unit and a second recording unit that ejects cyan ink, a third recording unit and a fourth recording unit that ejects magenta ink, a fifth recording unit that ejects light blue ink, and black. A recording head in which a sixth recording unit and a seventh recording unit for ejecting ink are arranged in a predetermined direction and move in a direction intersecting the predetermined direction with respect to the recording medium to record an image. ,
In the predetermined direction, the fifth recording unit, the sixth recording unit, and the seventh recording unit are provided between the first recording unit and the second recording unit in this order.
Moreover, the fifth recording unit, the sixth recording unit, and the seventh recording unit are provided between the third recording unit and the fourth recording unit.
Further, the recording head is characterized in that a recording unit for ejecting light blue ink is not provided on the opposite side of the sixth recording unit with the seventh recording unit interposed therebetween. The recording head according to any one of claims 1 to 16.
A control means for controlling the recording operation of ejecting ink from the recording head during reciprocating movement by the moving means equipped with the recording head, and
An inkjet recording device characterized by having.

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