JP2001219562A - Ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head in which nozzle pitch can be decreased without sacrifice of image quality. SOLUTION: This ink jet recording head comprises a plurality of pressure chambers 2, a plurality of nozzle openings 3 communicating with the plurality of pressure chambers 2, respectively, and a plurality of pressure generating elements 6 for generating pressure in the plurality of pressure chambers 2 to eject ink from the plurality of nozzle openings 3, respectively. The plurality of nozzle openings 3 are arranged in arrays such that at least three arbitrary adjacent nozzle openings 3 eject different inks.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head for generating pressure in a pressure chamber by a pressure generating element to discharge ink from nozzle openings.

[0002]

2. Description of the Related Art Generally, an ink jet recording head (hereinafter, referred to as a "recording head") to which a piezoelectric vibrator of a flexural vibration mode is attached has a plurality of pressure chambers 2 as shown in FIGS. Actuator unit 10 in which piezoelectric vibrator 6 is arranged corresponding to each pressure chamber 2
0, a nozzle opening 3 and an ink storage chamber 4 are formed,
A flow path unit 105 adhered to the lower surface of the actuator unit 100, wherein a pressure is generated in the pressure chamber 2 by the flexural vibration of the piezoelectric vibrator 6, and an ink droplet is ejected from the nozzle opening 3. .

The actuator unit 100 includes a pressure chamber forming substrate 10 in which a space for forming the pressure chamber 2 is formed,
A diaphragm 11 is located on the upper surface of the pressure chamber forming substrate 10 and closes an upper surface opening of the space. The pressure chamber 2 is formed in a long hole shape, and has one end communicating with the ink storage chamber 4 and the other end communicating with the nozzle opening 3.

The flow path unit 105 includes a storage chamber forming substrate 16 in which a space for forming the ink storage chamber 4 is formed, a nozzle plate 17 having a nozzle opening 3 formed therein and located on the lower surface of the storage chamber forming substrate 16. And a supply port forming plate 18 located on the upper surface of the storage chamber forming substrate 16. A nozzle communication port 9 communicating with the nozzle opening 3 is formed in the storage chamber forming substrate 16. In addition, an ink supply port 15 for supplying ink from the ink storage chamber 4 to the pressure chamber 2 is formed in the supply port forming plate 18, and the pressure chamber 2 communicates with the nozzle communication port 9 and the nozzle opening 3. A communication port 8 is formed. In FIGS. 10 and 11, reference numeral 24 denotes an ink inlet for introducing ink from an ink cartridge (not shown) into the ink storage chamber 4.

In this example, a recording head that performs printing using six color inks is shown. In this recording head, three sets of actuator units 100 each having two rows of pressure chambers 2 arranged in the recording paper feed direction are provided, and the actuator units 100 are arranged in the width direction of the recording paper, that is, the scanning of the recording head. Direction (main scanning direction). In the channel unit 105, six ink storage chambers 4 corresponding to each row of the pressure chambers 2 are provided so as to be arranged in the width direction of the recording paper (main scanning direction). And
Different colors of ink are ejected from the six rows of nozzle openings 3 corresponding to the respective rows of the pressure chambers 2.

The diaphragm 1 of the actuator unit 100
A plurality of lower electrodes 19 are formed on the upper surface of 1, and each of these lower electrodes 19 is formed above the pressure chamber 2. The plate-shaped piezoelectric vibrator 6 is formed on the upper surface of the lower electrode 19, and the upper electrode 20 is formed on the upper surface of the piezoelectric vibrator 6.

As shown in FIG. 10, each piezoelectric vibrator 6 is provided at both ends of the upper surface of the actuator unit 100.
A terminal 21 that is electrically connected to the upper electrode 20 is formed.
The flexible circuit board 22 is provided on the upper surface of the terminal 21.
Are extended so that a drive signal is applied to the piezoelectric vibrator 6 via the terminal 21 and the upper electrode 20.

In the recording head, when a drive signal is applied to the piezoelectric vibrator 6, the piezoelectric vibrator 6 contracts in the horizontal direction as shown in FIG. At this time, the lower surface side of the piezoelectric vibrator 6 fixed to the vibration plate 11 does not contract but only the upper surface side contracts, so that the piezoelectric vibrator 6 and the vibration plate 11 bend downward and compress the pressure chamber 2. When the pressure in the pressure chamber 2 rises, the ink in the pressure chamber 2 is ejected from the nozzle openings 3 as ink droplets 23, and dots are formed on recording paper or the like to perform printing. Next, when the piezoelectric vibrator 6 is discharged and returns to the original state, the pressure in the pressure chamber 2 is reduced, and new ink is supplied from the ink storage chamber 4 to the pressure chamber 2 through the ink supply port 15.

[0009]

In the recording head, the nozzle pitch in the row of the nozzle openings 3 has recently been narrowed. By narrowing the nozzle pitch, there are many advantages that the size of the recording head can be reduced, accuracy in assembling the recording head also decreases, and image quality decreases when paper feeding becomes unstable. Because.

However, narrowing the nozzle pitch makes it difficult to fill a blank between the nozzle pitches with dots of a constant pitch, and a boundary between dot lines is generated, which tends to lower the image quality. The problem arises.

That is, as shown in FIG. 13A, the nozzle pitch n is equal to the dot line pitch (print pitch) p.
8 times (for example, n = 8/720 inch, p = 1/7)
20 inches), the paper feed amount is mx
Assuming that n ± p (m is an integer equal to or greater than 0, m × n−p is a positive number, and the same applies hereinafter), 2 follows the dot line of the first pass (reference numeral 1 in the drawing; dots are indicated by oblique lines) The dot line of the pass is printed, then the third pass, the fourth pass, and so on are printed sequentially, and the dot line of the eighth pass is printed immediately before the dot line of the first first pass. Will fill in the blanks.

However, when dot lines are sequentially printed in this way, an error in the paper feed amount is accumulated between the dot lines in the eighth pass and the first pass, and it is not possible to sufficiently fill the space. 8 on pass ink dry
The problem that the boundary is visible when the path is printed is likely to occur.

Therefore, as shown in FIG. 13 (b), by setting the paper feed amount to m × n ± 3p (or m × n ± 5p), blank spaces between nozzle pitches can be filled at regular intervals. Has been done.

Here, by narrowing the nozzle pitch n, the nozzle pitch is made six times as large as the dot line pitch n (for example, 6/720 inc.
h), as shown in FIG. 14A, assuming that the paper feed amount is m × n ± 2p (or m × n ± 4p),
The dot line in the fourth pass overlaps the dot line in the first pass, and it is not possible to fill the space between the nozzle pitches (even if the paper feed amount is m × n ± 3p, the dot line in the third pass is A similar result is obtained by overlapping with the dot line of the eye). Therefore, when the nozzle pitch n is designed to be narrow, as shown in FIG. 14 (b), it is necessary to sequentially print the dot lines, and as described above, it is not possible to sufficiently fill the space or to make the boundary visible. Problem easily occurs.

Further, in the recording head, six ink storage chambers 4 are formed on one storage chamber forming substrate 16, and the ink storage chambers 4 pass through the pressure chambers 2 from the six rows of the nozzle openings 3 to form ink from the rows of the nozzle openings 3. Is discharged. As described above, since the six ink storage chambers 4 are arranged in the scanning direction (main scanning direction) of the recording head, there is a problem that the size of the recording head in the main scanning direction necessarily increases. In recent years, it has been considered to increase the number of ink colors in order to further improve print quality.However, if the number of colors is increased beyond the current level, the size of the recording head becomes larger and the accuracy is also reduced. At present, it has not been realized because it is not preferable. Further, one row of pressure chambers 2 is divided into a plurality of blocks, and a plurality of ink storage chambers 4 are arranged in the same row.
There is also proposed a recording head that ejects a plurality of colors of ink by providing a plurality of ink storage chambers 4 on a single storage chamber forming substrate. There are limits to what you can do.

The present invention has been made in view of such circumstances, and has as its object to provide an ink jet recording head and an ink jet recording apparatus which can narrow a nozzle pitch without deteriorating image quality.

[0017]

According to another aspect of the present invention, there is provided an ink jet recording head comprising: a plurality of pressure chambers; a plurality of nozzle openings communicating with each of the plurality of pressure chambers; A plurality of pressure generating elements for generating pressure in each of the pressure chambers to discharge ink from each of the plurality of nozzle openings, wherein the plurality of nozzle openings are arranged in a row, and At least three of the nozzle openings are configured to eject different types of ink.

Preferably, the plurality of nozzle openings are arranged so that the arrangement pitch between the nozzle openings for discharging the same type of ink is constant.

Preferably, the plurality of nozzle openings are arranged such that the nozzle openings for discharging each type of ink are arranged in a repetitive pattern in a predetermined order.

Preferably, there is provided a flow path unit in which at least three ink storage chambers for storing ink to be supplied to the plurality of pressure chambers are formed, and the flow path unit has a space corresponding to the ink storage chamber. Are formed by laminating a plurality of storage chamber forming plates on which a plurality of storage chamber forming plates are formed.

Preferably, the flow path unit is
It has at least two storage chamber forming plates, and at least one of the at least two storage chamber forming plates has the two ink storage chambers formed therein.

Preferably, the two ink storage chambers formed on at least one of the at least two storage chamber forming plates each have a storage extending along an arrangement direction of the plurality of nozzle openings. A space portion, and a plurality of protruding flow paths extending in a direction transverse to the arrangement direction of the plurality of nozzle openings from the storage space portion and forming a comb-like shape as a whole, and including one of the storage space portions. The plurality of protruding flow paths and the plurality of protruding flow paths of the other storage space extend in directions facing each other and are alternately arranged.

According to another aspect of the present invention, there is provided an ink jet recording apparatus according to any one of the above ink jet recording heads, wherein the same number of nozzle openings are formed for each type of ink. A head and feed control means for feeding the recording medium in the sub-scanning direction at the stage when one scan in the main scanning direction of the ink jet recording head is completed, wherein And a feed control unit whose feed amount is a value obtained by multiplying the number of the nozzle openings per ink type by a print pitch.

[0024]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 and FIG. 2 are views showing an ink jet recording head according to the present embodiment and an ink jet recording apparatus provided with this recording head. This print head is similar to the conventional print head shown in FIGS. 9 to 11 in terms of the basic configuration for ejecting ink droplets. Hereinafter, the portions having the same functions as the conventional print head will be described. Will be described with the same reference numerals.

As shown in FIG. 1, the recording head according to the present embodiment has an actuator unit 1 in which a plurality of pressure chambers 2 are formed, and a piezoelectric vibrator 6 is disposed in correspondence with each pressure chamber 2, and a nozzle opening. 3 and ink storage chambers 4A, 4B,
4C, 4D, and a flow path unit 5 attached to the lower surface of the actuator unit 1. Then, a pressure is generated in the pressure chamber 2 by the flexural vibration of the piezoelectric vibrator 6, and an ink droplet is ejected from the nozzle opening 3.

The actuator unit 1 includes a pressure chamber forming substrate 10 in which a space for forming the pressure chamber 2 is formed, a vibrating plate 11 located on the upper surface of the pressure chamber forming substrate 10 and closing the upper opening of the space. And a piezoelectric vibrator 6 arranged corresponding to each pressure chamber 2. Each of the pressure chambers 2 is formed in an elongated hole shape, and one end of the pressure chamber 2 has an ink storage chamber 4.
A, 4B, 4C, and 4D, and the other end is a nozzle opening 3
It is designed to communicate with Further, the pressure chambers 2 are provided so as to form two rows in a line in the recording paper feed direction.

A lower electrode 19 is formed on the upper surface of the vibration plate 11 of the actuator unit 1, and these lower electrodes 19 are formed above the pressure chamber 2, respectively. The plate-shaped piezoelectric vibrator 6 is formed on the upper surface of the lower electrode 19, and the upper electrode 20 is formed on the upper surface of the piezoelectric vibrator 6.

The flow path unit 5 includes the ink storage chambers 4A and 4A.
Two storage chamber forming substrates 16A and 16B in which spaces for forming B, 4C and 4D are formed, and these storage chamber forming substrates 1
6A, 16B, the ink storage chambers 4A, 4B,
A partition plate 12 for sealing the openings of 4C and 4D, a nozzle plate 17 provided with a nozzle opening 3 and located on the lower surface of the storage chamber forming substrate 16A, and a supply port formed on the upper surface of the storage chamber forming substrate 16B. The plate 18 is laminated. The ink storage chambers 4A and 4C are used as storage chamber forming substrates 16B.
The ink storage chambers 4B and 4D are formed on a storage chamber forming substrate 16A.

Each of the ink storage chambers 4 is provided with a supply port forming plate 18.
A plurality of ink supply ports 15 for supplying ink from A, 4B, 4C, and 4D to a plurality of pressure chambers 2 are formed,
A communication port 8 for communicating each pressure chamber 2 with each nozzle opening 3 is formed. Eight ink inlets 24A, 24B, 24 for introducing ink from ink cartridges (not shown) into the respective ink storage chambers 4A, 4B, 4C, 4D.
C and 24D are provided in a line in the scanning direction (main scanning direction) of the recording head. On the other hand, the nozzle plate 17 has
The plurality of nozzle openings 3 are arranged in two rows so as to correspond to the rows of the pressure chambers 2 of the actuator unit 1.

In the first storage chamber forming substrate 16A, the nozzle communication ports 9 communicating with the nozzle openings 3 are arranged in a row, and the second ink storage chamber 4B and the fourth ink storage chamber 4D are provided.
Is formed. One end of the second and fourth ink storage chambers 4B and 4D has an ink introduction portion 13B,
13D, the ink introduction portions 13B, 13D
Are connected to the ink inlets 24B and 24D through the inlet communication holes 25B and 25D formed in the partition plate 12 and the second storage chamber forming base 16B.

The second ink storage chamber 4B has a storage space 40B extending along the direction in which the plurality of nozzle openings 3 are arranged, and the second ink storage chamber 4B extends from the storage space 40B in a direction transverse to the direction in which the plurality of nozzle openings 3 are arranged. And a plurality of protruding flow paths 41B having a comb shape.
The supply unit supplies the pressure chamber 2 with ink. The fourth ink storage chamber 4D has a storage space 40D extending along the direction in which the plurality of nozzle openings 3 are arranged, and the fourth ink storage chamber 4D extends from the storage space 40D in a direction transverse to the direction in which the plurality of nozzle openings 3 are arranged. A plurality of protruding flow paths 4 having a comb shape
1D. The protruding flow path 41 </ b> D is a supply unit that supplies ink to the pressure chamber 2. The plurality of protruding channels 41D extend in a direction facing the plurality of protruding channels 41B, and are arranged alternately with the plurality of protruding channels 41B. And each said protruding flow path 41B, 41D,
It communicates with the ink supply port 15 and the pressure chamber 2 through a storage chamber communication hole 26A formed in the partition plate 12 and the second storage chamber forming base 16B.

Thus, the ink introduced from the ink cartridge or the like (not shown) into the ink inlets 24B, 24D passes through the inlet communication holes 25B, 25D, and from the ink inlets 13B, 13D to the second and fourth ink inlets. Ink storage room 4
B, 4D. The ink in the second and fourth ink storage chambers 4B and 4D flows from the protruding flow paths 41B and 41D into the pressure chamber 2 through the storage chamber communication hole 26A and the ink supply hole 15.

The partition plate 12 is provided with a first storage chamber forming substrate 16.
A between the first and third ink storage chambers 4B and 4D, and between the upper openings of the second and fourth ink storage chambers 4B and 4D and the lower openings of the first and third ink storage chambers 4A and 4C. It has become. The partition plate 12 has the nozzle communication ports 9 communicating with the respective nozzle openings 3 arranged in line, and as described above, the second and fourth ink storage chambers 4.
B, 4D ink introduction portions 13B, 13D communicate with the ink introduction ports 24B, 24D introduction port communication holes 25B, 25
D and a storage chamber communication hole 26A for connecting the projecting flow paths 41B, 41D of the second and fourth ink storage chambers 4B, 4D to the ink supply port 15 and the pressure chamber 2 are formed.

In the second storage chamber forming substrate 16B, the nozzle communication ports 9 communicating with the respective nozzle openings 3 are arranged in a row, and the first ink storage chamber 4A and the third ink storage chamber 4C are provided.
Is formed. One end of the first and third ink storage chambers 4A and 4C has an ink introduction portion 13A,
13C, and these ink introduction portions 13A, 1
3C are the ink inlets 24A, 24 of the supply port forming plate 18.
It communicates with C.

The first ink storage chamber 4A has a storage space 40A extending along the direction in which the plurality of nozzle openings 3 are arranged, and the first ink storage chamber 4A extends from the storage space 40A in a direction transverse to the direction in which the plurality of nozzle openings 3 are arranged. And a plurality of protruding flow paths 41A having a comb shape.
The supply unit supplies the pressure chamber 2 with ink. The third ink storage chamber 4C has a storage space 40C extending along the direction in which the plurality of nozzle openings 3 are arranged, and extends from the storage space 40C in a direction transverse to the direction in which the plurality of nozzle openings 3 are arranged. A plurality of protruding flow paths 4 having a comb shape
1C. The projecting flow channel 41C is a supply unit that supplies ink to the pressure chamber 2. The plurality of protruding flow paths 41C extend in a direction facing the plurality of protruding flow paths 41A and are arranged alternately with the plurality of protruding flow paths 41A. And each said protruding flow path 41A, 41C,
It communicates with the ink supply port 15 and the pressure chamber 2.

Thus, the ink introduced from the ink cartridge or the like (not shown) into the ink introduction ports 24A, 24C flows from the ink introduction sections 13A, 13C into the first and third ink storage chambers 4A, 4C. It has become. The ink in the first and third ink storage chambers 4A, 4C is supplied from the protruding flow paths 41A, 41C to the ink supply holes
5 and flows into the pressure chamber 2.

Further, the second storage chamber forming substrate 16B includes:
As described above, the second and fourth ink storage chambers 4B, 4B
D ink introduction portions 13B and 13D
Inlet communication holes 25B, 25D communicating with B, 24D
And a storage chamber communication hole 26A for connecting the projecting flow paths 41B, 41D of the second and fourth ink storage chambers 4B, 4D to the ink supply port 15 and the pressure chamber 2. The storage chamber communication hole 26A is connected to the third and fourth ink storage chambers 4C and 4C.
D is located between the projecting flow paths 41C and 41D. That is, the first to fourth ink storage chambers 4A, 4B, 4C, 4D
Are arranged in a repetitive pattern in this fixed order (ABCD...). The first to fourth ink storage chambers 4A, 4A
The nozzle openings 3 communicating with B, 4C and 4D are also arranged in the chestnut lyric pattern in this fixed order (ABCD...).

Then, the first and second storage chamber forming substrates 1
6A, 16B, partition plate 12 and supply port forming plate 1
8. The flow path unit 5 is configured by laminating the nozzle plates 17. As can be seen from FIG. 2, in the flow channel unit 5, the first and second ink storage chambers 4A and 4B and the third and fourth ink storage chambers 4C and 4D are provided so as to substantially overlap on the same projection plane. Can be

In this print head, four ink storage chambers 4A, 4B, 4C, and 4D communicate with one row of pressure chambers 2, and discharge four colors of ink in one row. It is possible to print using the ink. Further, as shown in FIG. 3, the nozzle openings 3 (A, B, C, D) which communicate with the first to fourth ink storage chambers 4A, 4B, 4C, 4D and discharge the respective color inks are fixed. Order (ABCD) repetition pattern (ABCABCD
..), And the nozzle pitches Pa, Pb, Pc, Pd of the nozzle openings 3 for discharging the same color ink are provided so as to be constant. Then, in the same row of nozzle openings 3, any four adjacent nozzle openings 3 eject ink of different colors.

As described above, in the recording head according to the present embodiment, within the same row of nozzle openings 3, any four adjacent nozzle openings 3 discharge ink of different colors (total of four colors). Therefore, even if the nozzle pitch Pn is narrowed, the nozzle pitches Pa, Pb, Pc, Pd of the same color can be made sufficiently large. Therefore, the nozzle pitch Pn can be made sufficiently small, and the size of the recording head can be reduced, so that a decrease in accuracy at the time of assembling the recording head is reduced, and a decrease in image quality when paper feeding becomes unstable is also reduced. In addition, there is no problem that the space cannot be sufficiently filled or the boundary is visible as in the related art.

The flow channel unit 5 is formed by laminating two storage chamber forming plates 16A and 16B in which spaces corresponding to the first to fourth ink storage chambers 4A, 4B, 4C and 4D are formed. Since the first and second ink storage chambers 4A and 4B and the third and fourth ink storage chambers 4C and 4D formed on the respective storage chamber forming plates 16A and 16B are stacked substantially upward in the same projection plane. In addition, the size of the recording head itself can be significantly reduced. Further, even if the number of ink storage chambers is increased by increasing the number of ink colors to be used, the size of the recording head itself does not need to be so large because the ink storage chambers are stacked in the vertical direction.

FIG. 4 is a diagram showing a schematic configuration of an ink jet recording apparatus provided with the ink jet recording head according to the present embodiment. In FIG. 4, reference numeral 200 denotes the recording head shown in FIGS. 1 and 2, and the recording head 200 is attached to the carriage 201. A carriage 201 is reciprocally mounted on a guide member 203 provided in parallel with an axial direction of a platen 202, and is connected to a motor 205 via a timing belt 204.
To drive at a predetermined speed.

In FIG. 4, reference numeral 206 denotes a paper feed motor, which in this example is connected to the platen 202 via a transmission mechanism. The paper feed motor 206 is controlled by the paper feed control means 207 to feed the recording paper (recording medium) in the sub-scanning direction.

The data extracting means 208 expands the data and code data sent from the host (not shown) into bitmap data and converts the data and code data from the bitmap data stored in the image memory 209 based on a command from the print control means 210. Thus, data corresponding to each nozzle opening 3 (FIG. 1) is extracted and output to the head drive circuit 211. The control data storage unit 213 is connected to the print control unit 210.

The head drive circuit 211 includes the print control unit 2
The magnitude of the driving signal applied to the piezoelectric vibrator 6 so that the diameter of the dot formed on the recording paper in accordance with the signal relating to the recording density sent from the nozzle 10 can be adjusted by the volume of the ink droplet ejected from the nozzle opening 3. Also, after the pressure chamber 2 is once expanded and the ink is sucked into the pressure chamber 2, a function of controlling the timing of contracting the pressure chamber 2 for discharging ink is provided.

The print control means 210 outputs a print timing signal every time the feed amount of the print head 200 reaches a predetermined value according to a signal from the carriage control means 212 corresponding to the recording density. The paper feed control means 207 includes the recording head 2
When one scan in the main scanning direction of 00 is completed, the recording medium is fed by a predetermined amount in the sub-scanning direction.

According to this ink jet recording apparatus,
The following effects can be obtained. For convenience of explanation, first, a case of an ink jet type recording apparatus having a recording head having a configuration different from that of the recording head according to the present embodiment will be described with reference to FIGS.

If the plurality of nozzle openings 3 ′ in the recording head were to be set to the respective colors A, B, C, and D as shown in FIG.
When each nozzle row is formed and arranged for each of the nozzles, the A color is used when the main scanning direction (head moving direction) is printed from right to left at any printing position in the sub-scanning direction (paper feed direction).
Printing is performed in the order of B color, C color, and D color. When the main scanning direction is from left to right, printing is performed in the order of D color, C color, B color, and A color. Then, when bidirectional printing is performed using the recording head shown in FIG. 5, the overlapping order of the dots of each color is exactly opposite for each adjacent printing position or for each printing area where a plurality of printing positions are gathered. There is a problem that the difference in color at the border is regularly noticeable.

When printing in one direction is performed using the recording head shown in FIG. 5, the overlapping order of the dots of each color becomes constant, and the color becomes theoretically uniform. However, if a dot flight error, which cannot be avoided in manufacturing, occurs, the error appears regularly in a uniform formation, which again becomes noticeable.

On the other hand, as shown in FIG. 6, a plurality of nozzle openings 3 'in the recording head are arranged in a nozzle opening group (block) for each color A, B, C, D in each nozzle row. At any print position in the sub-scanning direction (paper feed direction), regardless of whether the main scanning direction is printing from right to left or from left to right, the colors A, B, C
Printing is performed in the order of color and D (or in the order of D, C, B, and A). For this reason, when printing is performed using the recording head shown in FIG. 6, errors in both bidirectional printing and unidirectional printing are noticeable for the same reason as in the case of the recording head shown in FIG. turn into.

On the other hand, when printing is performed using a recording apparatus having the ink jet recording head according to the present embodiment, the above problem does not occur as described below.

As shown in FIG. 7, in the recording head according to the present embodiment, four colors of A, B, C, and D are used, and the interval between adjacent nozzle openings 3 is set to two printing pitches (2
p), the intervals between the nozzle openings 3 of the same color are arranged at eight printing pitches (8p). The number of nozzle openings 3 for each color is calculated as a number that is prime to the number of array pitches of the same color (8 in the present example), for example, 8m + 3 (m is an integer).
And 11 is set.

After the recording head has completed one recording pass in the main scanning direction, the paper feed amount in the sub-scanning direction is set to 11 printing pitches equal to the number of nozzle openings 3 of each color. It is assumed that printing is performed by an interlace method in which paper is fed by an amount of 11 print pitches.

FIG. 8 shows how dots of each color are filled when printing is performed by the above-mentioned interlace method. The print positions 1 to 9 in the vertical column in FIG. 8 indicate the print positions in the sub-scanning direction at an arbitrary position in the print area, and the passes 1 to 8 in the horizontal column indicate the order of the recording passes.

As can be seen from FIG. 8, in the first pass, 2
The colors A, B, C, and D arranged at the print pitch interval record print positions 1, 3, 5, and 7, respectively. In the subsequent second pass, the paper is fed by 11 print pitches,
The color A existing on the print pitch records the print position 4. Similarly, the B color records the print position 6, the C color records the print position 8, and the D color records the print position 2.

Here, the overlapping order of each color dot will be considered. For example, if the line at print position 1 traces the side,
A color is recorded in the pass, B color in the third pass, C in the fifth pass
The color D is recorded in the seventh pass. Similarly, the line at the adjacent printing position 2 is D color in the second pass, A color in the fourth pass,
The B color is printed in the sixth pass, and the C color is printed in the eighth pass. further,
The line at the printing position 3 is B color in the first pass and C in the third pass.
The color D is recorded in the fifth pass, and the color A is recorded in the seventh pass.

As described above, since the overlapping order of the dots of each color and the number of passes for printing the same always change for each adjacent line, the uniformity of the printing result as a whole is improved.

The effect of printing by the above-described interlace method is as follows: when printing is performed in a single direction, when printing is performed bidirectionally with an odd pass as a forward direction and an even pass as a backward direction.
It is similarly obtained.

[0060]

As described above, according to the present invention, at least three arbitrary adjacent nozzle openings are configured to eject different types of ink, respectively.
Even if the nozzle pitch is narrowed, the distance between the nozzle openings for discharging the same type of ink can be increased. Therefore, the nozzle pitch can be made sufficiently small, the recording head can be miniaturized, and the accuracy decrease at the time of assembling the recording head decreases, and the image quality decreases when the paper feeding becomes unstable. Moreover, there is no problem that the space between the nozzle pitches cannot be sufficiently filled or the boundary is visible unlike the conventional recording head.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an ink jet recording head according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship between a pressure chamber and an ink storage chamber of the ink jet recording head shown in FIG.

FIG. 3 is an explanatory diagram showing a pitch of nozzle openings of the ink jet recording head shown in FIG.

FIG. 4 is a diagram illustrating a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention.

FIG. 5 is a diagram showing a comparative print head for explaining the operation and effect when printing is performed in an interlaced manner by the ink jet printing apparatus according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a comparative print head for describing the operation and effect when printing is performed in an interlaced manner by the inkjet printing apparatus according to the embodiment of the present invention.

FIG. 7 is a diagram for explaining the function and effect when printing is performed in an interlaced manner by the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 8 is a diagram for explaining the operation and effect when printing is performed in an interlaced manner by the ink jet recording apparatus according to the embodiment of the present invention.

FIG. 9 is an exploded perspective view showing a conventional ink jet recording head.

FIG. 10 is a sectional view of the ink jet recording head shown in FIG.

FIG. 11 is a perspective view showing the ink jet recording head shown in FIG.

FIG. 12 is an explanatory diagram showing the operation of the ink jet recording head shown in FIG.

FIG. 13 is an explanatory diagram showing a printing method of a conventional ink jet recording head.

FIG. 14 is an explanatory diagram showing another printing method of a conventional ink jet recording head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Actuator unit 2 Pressure chamber 3 Nozzle opening 4A, 4B, 4C, 4D Ink storage chamber 5 Flow path unit 6 Piezoelectric vibrator 10 Pressure chamber forming substrate 16A, 16B Storage chamber forming substrate 17 Nozzle plate 40A, 40B, 40C, 40D Storage Spaces 41A, 41B, 41C, 41D Projecting channel 200 Recording head

Claims (7)

[Claims] A plurality of pressure chambers, a plurality of nozzle openings communicating with each of the plurality of pressure chambers, and a pressure generated in each of the plurality of pressure chambers to supply ink from each of the plurality of nozzle openings. A plurality of pressure generating elements for discharging, the plurality of nozzle openings are arranged in a row,
An ink jet recording head, wherein at least three arbitrary adjacent nozzle openings eject different types of ink, respectively. 2. An ink jet type ink jet printer according to claim 1, wherein said plurality of nozzle openings are arranged such that the arrangement pitch between said nozzle openings for discharging the same kind of ink is constant. Recording head. 3. The method according to claim 1, wherein the plurality of nozzle openings are arranged such that the nozzle openings for ejecting each type of ink are arranged in a repetitive pattern in a predetermined order. Inkjet recording head. 4. A flow path unit having at least three ink storage chambers for storing ink to be supplied to the plurality of pressure chambers, wherein the flow path unit has a space corresponding to the ink storage chamber. The ink jet recording head according to any one of claims 1 to 3, wherein the plurality of storage chamber forming plates are laminated. 5. The flow path unit has at least two storage chamber forming plates, and at least one of the at least two storage chamber forming plates has two ink storage chambers formed therein. The ink jet recording head according to claim 4, wherein 6. An ink storage chamber formed on at least one of said at least two storage chamber forming plates, wherein each of said storage chambers extends along a direction in which said plurality of nozzle openings are arranged. A plurality of projecting flow paths extending in a direction transverse to the arrangement direction of the plurality of nozzle openings from the storage space and forming a comb-like shape as a whole, and the plurality of protrusions of one of the storage spaces are provided. 6. The ink jet recording head according to claim 5, wherein the flow path and the plurality of protruding flow paths of the other storage space extend in directions facing each other and are arranged alternately. 7. An ink jet recording head according to claim 1, wherein the same number of nozzle openings are formed for each type of ink; Feed control means for feeding the recording medium in the sub-scanning direction at the stage when one scan of the recording head in the main scanning direction has been completed, wherein the feed amount of the recording medium in the sub-scanning direction per time is one An ink jet recording apparatus comprising: a feed control unit that is a value obtained by multiplying the number of nozzle openings per type by a printing pitch.