JPH0839798A - Ink-jet recording head - Google Patents

Abstract

PURPOSE:To reduce distance error in an auxiliary scanning direction of adjacent lines which are printed by a recording head provided with three or more rows oh nozzle openings. CONSTITUTION:A plurality of nozzle openings are formed in an auxiliary scanning direction and nozzle opening rows A, B, C, D, E, F, which are divided into three groups 201, 202, 203 at certain intervals in a main scanning direction, are provided on a nozzle plate 130, and the nozzle openings of the groups 202, 203 disposed on the opposite sides of the middle group 201 compensate for the interval between the nozzle openings of the group 201 and one of the openings of the group 201 is located at the uppermost end or at the lowermost end. And lines printed by the groups 202, 203 on both sides are printed on the opposite sides of a line printed by the group 201 in the vertical direction, so that intervals between the nozzle openings in the main scanning direction can be made smaller, and hence error between the lines due to the inclination of a head can be reduced.

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 provided with three or more nozzle opening rows in the main scanning direction, each nozzle opening row having a plurality of nozzle openings in the paper feeding direction for ejecting ink droplets by pressure from a pressure generating source. More specifically, it relates to an array structure of nozzle openings.

[0002]

2. Description of the Related Art Ink jet recording heads are widely used because of their high recording density, adjustable dot size to some extent, and relatively low noise. Such ink jet recording heads include what is called a bubble jet type that uses heat energy from a heater,
Piezoelectric vibrator-driven type that uses displacement of the piezoelectric vibrator is roughly divided into two types. The latter one uses longitudinal vibration of the piezoelectric vibrator and flexural vibration of the piezoelectric vibrator. There are two types.

In the recording head utilizing the longitudinal vibration, the contact area of the piezoelectric vibrator with the vibration plate can be made small, so that the interval between the nozzle opening rows can be easily made small, but the assembly process becomes complicated. There is an inconvenience.

On the other hand, the one utilizing flexural vibration can be constructed by laminating a piezoelectric vibrating plate and other plate members constituting the flow path, so that the assembling process can be simplified, while the piezoelectric vibrating plate is used. Since the size of the diaphragm is larger than that of the former, there is a disadvantage that the distance between the nozzle opening rows becomes large.

Not only that, when the distance between the nozzle opening rows becomes large, if three or more rows of nozzle opening rows are formed in order to improve the printing quality, an error between dots in the sub-scanning direction printed on the recording paper may occur. There is a problem in that the print quality tends to be large and the print quality is degraded.

That is, in a recording head in which a plurality of nozzle opening rows are arranged, the nozzle openings at the uppermost end and the lowermost end of the recording head are printed because dots at specific positions in the sub-scanning direction are printed by each nozzle opening row. Are arranged at one end and the other end in the main scanning direction. Therefore, if the distance between the nozzle opening rows at one end and the other end in the main scanning direction is G, if there is an inclination θ between the direction of the nozzle opening rows of the recording head and the paper feeding direction, the paper feeding An error of G × sin θ occurs between the front and rear lines in the sub-scanning direction to generate a white line or a black line, which causes a problem that print quality deteriorates.

In order to solve such a problem, the applicant of the present invention has found that, as previously disclosed in European Patent Publication No. 554907, a plurality of nozzle openings are provided in the paper feeding direction at a pitch corresponding to the number of nozzle opening rows. We proposed an ink jet recording head in which four nozzle opening rows, which are arranged in a straight line, are arranged so that the positions in the main scanning direction differ from the physical arrangement order and are displaced by a constant pitch. According to this, the distance in the sub-scanning direction between the nozzle opening at the uppermost end and the nozzle opening at the lowermost end of the recording head is reduced, and white lines or black lines caused by the misalignment angle θ between the nozzle opening row and the paper feeding direction. It becomes possible to prevent the generation of lines.

However, this is limited to the case where the number of nozzle opening rows is 4, and there is a disadvantage that the applicable range is narrow.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to be applicable to a recording head having three or more rows of nozzle openings. Make the distance error between lines as small as possible,
An object of the present invention is to provide an ink jet recording head capable of performing high quality printing.

[0010]

In order to solve such a problem, according to the present invention, a plurality of nozzle openings are formed in the sub-scanning direction and divided into three groups at regular intervals in the main scanning direction. Nozzle openings of different groups are provided on the same substrate, and the nozzle openings of other groups arranged on both sides of the group located in the central portion in the main scanning direction complement the nozzle openings of the group arranged in the central portion. And the nozzle openings of the group arranged in the central portion are located at the uppermost end or the lowermost end, and the line printed by the groups arranged on both sides is defined by the group arranged in the central portion. Printing was performed with the line to be printed sandwiched.

[0011]

Since the lines printed by the groups arranged on both sides are printed so as to sandwich the line printed by the group arranged in the central portion, the distance in the main scanning direction of the nozzle openings for printing the adjacent lines. However, it becomes about half of the maximum distance between the nozzle opening rows, the position error between lines due to the inclination of the recording head becomes small, and the error between lines in the sub-scanning direction at the band break before and after one line feeding becomes small.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. 2 and 3 are an exploded perspective view showing an embodiment of a recording head to which the present invention is applied, and a cross-sectional view showing a structure in the vicinity of a pressure generating chamber connected to one common ink chamber. Medium numbers 100, 100, 100 are
In the piezoelectric vibrator driving unit, a piezoelectric vibrating plate 1 made of PZT is formed on the surface of a vibrating plate 102 made of a thin plate of zirconia with a thickness of about 10 μm so as to face a pressure generating chamber 103 described later.
04, 104, 104 ... Are fixed.

Reference numeral 105 denotes a spacer, which is the pressure generating chamber 103.
Of the pressure generating chamber 1 on a ceramic plate of zirconia (ZrO2) or the like having a thickness suitable for forming
Through holes 10 conforming to the shapes of 03, 103, 103 ...
6, 106, 106 ... Are drilled at a constant pitch.

Reference numeral 108 denotes a substrate for sealing the other surface of the pressure generating chamber 103, and the nozzle openings 131, 131, 131, ...
, Which are larger than the nozzle openings for connecting 103, 103, ..., And the pressure generating chambers 103, 103, 103, ... And a common ink chamber 110 are provided on the other end side. Connecting holes 111, 111, 11 to be connected
1 is provided.

These three members 100, 105, 108
Have the same structure as each unit, and are attached to a unit fixing plate 112 described later.

Reference numeral 112 is a unit fixing plate on one surface of which each unit described above is fixed at a predetermined position with an adhesive.
In this embodiment, it also serves as a flow path limiting plate, and the conduction hole 111
And a common ink chamber 110 are provided with a flow path limiting hole 113 having a flow path resistance substantially equal to that of the nozzle opening, and nozzle openings 131, 1 are provided at positions facing the through hole 109.
31, 131 ... Pressure generating chambers 103, 103, 103.
A conduction hole 114 for connection with is provided.

Reference numeral 115 denotes a heat-welding film for joining a common ink chamber constituting plate 118 and a unit fixing plate 112, which will be described later, to the window 11 corresponding to the common ink chamber 110.
6 and nozzle holes 131, 131, 131, ... And through holes 117, 117, 117, ... Which connect the pressure generating chambers 103, 103, 103 ,.

Reference numeral 118 denotes the above-mentioned common ink chamber forming plate, which has a thickness suitable for forming the common ink chamber 110, for example, a plate material having corrosion resistance such as stainless steel having a thickness of 150 μm. ..., pressure generating chambers 103, 103, 103, ..., and nozzle openings 131, 1 corresponding to the shape.
Nozzle openings 131, 13 for connecting with 31, 131, ...
1, 131 ... Larger through holes 121, 121, 1
21 are formed by drilling.

Reference numeral 130 denotes a nozzle plate, which is the pressure generating chamber 1.
Nozzle openings 131, 131, 131 on one side of 03.
Are fixed to the common ink chamber forming plate 118 by the heat-welding film 133, and the conductive holes 109,
114, 121 via the pressure generating chambers 103, 103,
103 ... In addition, reference numeral 134 in the drawing is
The through-hole which connects the nozzle opening 131 and the conduction hole 121 is shown.

From the pressure generating chamber 103 to the nozzle opening 1
The flow path of the ink to 31 is the through hole 10 of the spacer 105.
6, the through hole 109 of the substrate 108, and the unit fixing plate 1
Ink is discharged from the pressure generating chamber 103 located on the back surface side of the recording head body toward the nozzle opening 131 on the front surface side by the communication holes 114 of 12 and the communication holes 121, 121 ... Of the common ink chamber forming plate 118. It is formed so as to flow from the horizontal direction to the vertical direction.

By adopting such a laminated structure, the conductive hole 109 of the substrate 108, the conductive hole 114 of the unit fixing plate 112, and the conductive hole 1 of the common ink supply chamber forming plate 118.
The nozzle openings 131 can be moved by ΔL by sequentially shifting the positions of the nozzles 21 while maintaining the communication state with each other, as shown in FIG. That is, when the tip end side of the pressure generating chamber 103 is displaced as shown in FIG. 4A, the nozzle opening can be positioned in front of the pressure generating chamber 103, and FIG.
As shown in (c), the pitch of the nozzle openings 131 adjacent to each other can be arbitrarily adjusted by sequentially shifting the through holes 109, 114, 121 in either direction with respect to the axis of the pressure generating chamber 103. it can.

In the apparatus thus configured, when a drive signal is applied to the piezoelectric vibrating plate 103, the vibrating plate 102 bends so that the pressure generating chamber 103 side is convex, and the pressure generating chamber 103 is contracted. As a result, the pressure generating chamber 103
Of the ink reaches the nozzle opening 131 via the conduction holes 109, 114, 121, and is ejected from there as an ink droplet.

When the drive signal is removed after ink droplet formation, the piezoelectric vibrating plate 104 returns to its original position and the pressure generating chamber 103 expands. As a result, the ink consumed by the formation of the ink droplets passes from the common ink chamber 110 through the flow path restriction hole 113 and the conduction hole 111, and the pressure generation chamber 10
Inflow to 3. Thereafter, ink droplets necessary for printing are ejected by repeating such a process.

FIG. 1 shows an embodiment of the arrangement of the nozzle openings of the above-mentioned laminated type ink jet recording head. In the figure, reference numeral 130 is the above-mentioned nozzle plate, and six nozzle opening rows A, B, C, D, E, F are formed and the first
Nozzle openings in rows Nozzle openings 1, 7, 13, 19, in rows A,
25 are arranged closest to the center line of the nozzle plate 130, and the nozzle openings 2 of the second nozzle opening row B are
8, 14, 20, 26, ... Are arranged at one end of the nozzle plate 130 on one side, that is, at the left end in the drawing in this embodiment, and the nozzle openings of the third nozzle opening row C are closest to this. 3, 9, 15, 21, 27, ... Are arranged.

On the other side of the nozzle opening row A of the first row, the nozzle openings 4, 10, 16 ... 28 of the nozzle opening row D of the fourth row are provided.
However, the nozzle openings 5 and 1 of the nozzle opening row E of the fifth row are
29 are arranged at the other end of the nozzle plate on the other side, that is, at the right end in the drawing in this embodiment, and further toward the center of the fifth nozzle opening row E, the nozzle openings 6 of the sixth nozzle opening row F, 12, 18, ..., 30 are arranged.

In these nozzle opening rows, the first nozzle opening row A and the fourth nozzle opening row D are the first group 201.
And the second and third nozzle opening rows are the second group 2
02, and the fifth and sixth nozzle opening rows E and F form a third group 203. Each group 201, 20
As described above, the nozzle openings 2 and 203 may be configured to communicate with the piezoelectric vibrating plate, the vibrating plate, and the substrate, which are unitized, and to be supplied with the ink to be ejected.

The nozzle openings 1, 4, 7, ... 22, 25, 28 formed as the first group 201 are arranged so as to have a pitch of 3 dots in the sub-scanning direction, that is, in the vertical direction in the drawing. ing.

Nozzle openings 2, 3 of the second group 202,
21, ..., 26, 27 are between the odd dots and the even dots of the first group, that is, 1-4, 7-10 ,.
In order to complement 28, it is arranged at a pitch of 1 dot, and this pitch is repeated at a cycle of 5 dots.

Nozzle openings 5, 6 of the third group 203,
11 ... 30 are the first not complemented by the second group
Between the nozzle openings of the group 201, that is, the even and odd dots 4-7, 10-13, ...
They are arranged at a dot pitch, and this pitch is repeated at a cycle of 5 dots.

Next, the printing operation when such an arrangement of nozzle openings is adopted will be described with reference to FIG. Note that FIG. 5A is a diagram for associating the nozzle openings printed with the positions of the horizontal lines and showing the distance between the nozzle openings printed with the lines printed adjacent to each other in an easy-to-understand manner. The enclosed numbers correspond to the numbers of the nozzle openings in FIG. The nozzle openings 1, 4, 7, ... 22, 25, 28 of the nozzle opening rows A and B of the first group 201
Prints lines at intervals of 3 dots. And the second
Nozzle openings 2, 38 of the nozzle opening rows B, C of the group
.., 21, 26, and 27, two lines are printed so as to complement the odd-even lines of the first group, that is, 1-4, 7-10, ... 25-28, and the nozzles of the third group. Nozzle openings 5, 6, 7, ... 2 in the opening rows E, F
4, 29, 30 between the even-odd lines not complemented by the second group 202, that is, 4-7, 10-1
Two lines are printed so as to complement 3, ..., 22-25.

Then, the second and third groups 202, 20
3, that is, the nozzle opening rows B and C arranged on both sides,
Since E and F print so as to sandwich the line printed by the first group arranged in the central portion, the distance in the main scanning direction between the nozzle openings of the lines printed adjacent in the vertical direction is The distance is approximately 1/2 of the distance between the groups arranged on both sides of the nozzle plate 130.

Therefore, even if the arrangement direction of the nozzle opening rows of the recording head is not parallel to the paper feeding direction but is attached to the carriage with a slight inclination, that is, the adjacent line An error amount G × sin θ when the distance in the main scanning direction between the nozzle opening rows at both ends of the main scanning direction for printing is G and the tilt angle of the head is θ.
However, it is almost half.

In this embodiment, the first group,
That is, the nozzle opening rows A and D arranged in the central portion are located at the uppermost line, and the second or third group 2
Since the nozzle openings of Nos. 02 and 203 are arranged so that the bottommost line is printed, the nozzle openings for printing the upper and lower lines before and after the paper feeding (see FIG. 5).
In (a), the nozzle opening 30 corresponds to the nozzle opening 1)
The distance in the main scanning direction between the two is also half the distance of the groups at both ends, the error in the distance between the lines before and after paper feeding is halved, and the occurrence of white and black lines that tend to occur during paper feeding is prevented. be able to.

That is, as shown in FIG. 5B, in the conventional printer that prints lines based on the arrangement order of the nozzle opening rows, the nozzle openings arranged at both ends (nozzle row A in the figure). For the vertically adjacent lines printed by'and the nozzle opening row F ', for example, by 6 and 7) surrounded by ◯, the distance in the main scanning direction is the distance between both ends of the nozzle opening row, so the error due to the inclination is Also, since the lines before and after feeding one line are also printed by the nozzle openings arranged at both ends, the error in the interval between the lines becomes large for the same reason.

FIG. 6 shows a second embodiment of the present invention with an arrangement of nozzle opening rows, which is designated by reference numeral 204 in the drawing.
Reference numerals 205 and 206 denote groups of nozzle opening rows formed on the nozzle plate 130, respectively.
No. 04 nozzle opening row A has a pitch of 4 dots per row in the paper feed direction, two nozzle opening rows B and C are formed in the second group 205, and one row in the third group 206. Nozzle opening row C is formed.

Nozzle openings 1, 5, 9, 13, ... 21, 2 are arranged at a 4-dot pitch in the nozzle opening row A of the first group.
No. 5 has nozzle openings 2, 4, 6, 10, ... 26, 28 with a 2-dot pitch in the second group, and nozzle openings 3, 7, 11, ... 2 with a 4-dot pitch in the third group.
3, 27 are formed, and the first and third groups 204 and 206 arranged on both sides are configured to alternately complement the nozzle openings of the second group 205 arranged in the central portion.

Also in this embodiment, the nozzle openings 2, 4, ...
The first group 204 so as to sandwich the line by 28
Nozzle openings 1, 5, ... 21, 25, 3rd group 2
Since the lines of the nozzle openings 3, 7, ... 23, 27 of No. 06 are printed, the nozzle opening rows A and D arranged at both ends even if the distance between the nozzle opening rows for printing the vertically adjacent lines is the maximum. Since the nozzle opening 1 of one of the groups, which is half the distance and is arranged on both sides, in this embodiment, the nozzle opening 1 of the group 204 is located at the uppermost end, and the nozzle opening 28 of the group 205 located in the center is located at the lowermost end. ,
The distance between the nozzle opening rows that print vertically adjacent lines before and after the paper feed is almost half the maximum distance between the nozzle opening rows, and the distance error between the lines is reduced.

As shown in FIG. 7, the second group 2
It is obvious that the same operation can be achieved even if the arrangement of the two nozzle opening rows B and C forming 05 is reversed.

Further, in the above-mentioned embodiment, the nozzle opening row of the group 205 arranged in the central portion is constituted by the two nozzle opening rows B and C, but as shown in FIG. Arranged nozzle openings 2, 4, 6, ...
The group 211 provided with 24, 26, 28 and the nozzle openings 1, 5, ... Having a pitch of 4 dots which complement the nozzle openings 2, 4, 6 ,.
... Group 210 of nozzle opening row A consisting of 21, 24
, And a group 212 of nozzle openings C composed of the nozzle openings 3, 7, ..., 23, 27 can be arranged.

The group 21 arranged in the central portion
When the nozzle openings are arranged on the same straight line with extremely high density like the nozzle opening row B of No. 1, the position where the nozzle openings should be arranged as shown in FIG. 9 (line indicated by L-L in the figure)
Of the pressure generating chambers 10 in two rows by bringing their ends as close to each other as possible.
3, 103, 103 ... 103 ', 103', 10
3 '... are arranged facing each other, and the pressure generating chamber 1 on one side
03 and the nozzle opening 131 connect the conducting holes 109, 1
14, 121, and conducting holes 109 ', 114' for connecting the pressure generating chamber 103 'on the other side and the nozzle opening 131',
It can be realized by displacing 121 'toward the line LL and guiding the ink flow path on this line.

Also in this embodiment, the nozzle openings 2 of the nozzle opening row B arranged in the central portion, as in the above-mentioned embodiments,
Nozzle openings 1, 5, of groups A, C having lines printed by 4, 6 ,.
9 ... 21, 24 and nozzle openings 3, 7, 11 ... 2
Alternately complemented by the lines printed by 3, 27,
Further, since the nozzle openings 1 of the groups 210 and 212 arranged on both sides are located at the uppermost end and the nozzle openings 28 of the group 211 arranged in the central portion are located at the lowermost end, the error between the lines becomes small.

Incidentally, in the above-described embodiments of FIGS. 6, 7 and 8, the nozzle openings of the nozzle opening rows belonging to the central groups 205 and 211 are located at the lowermost end of the recording head. , Central group 205, 21
It is obvious that the same effect can be obtained even if the nozzle openings of the nozzle opening row belonging to No. 1 are located at the uppermost end of the recording head.

For example, when the embodiment shown in FIG. 6 is taken as an example, the nozzle opening row A belonging to the group 204 on the left side of the drawing is shifted downward by 4 dots, that is, the nozzle opening 1
Is set at the position of the nozzle opening 5, and thereafter, the order of the numbers of the nozzle openings currently being shaken, that is, 2, 3, 4, 5, ...
It may be printed as 27, 28.

Also in FIGS. 7 and 8, the uppermost nozzle opening 1 of the nozzle opening row A of the groups 204 and 210 on the left side of the drawing is omitted or is not used in the central portion in the same manner as described above. It is obvious that printing may be performed in the order of the nozzle numbers from the nozzle openings 2 of the nozzle opening row of the group.

As described above, when the number of nozzle openings in the nozzle opening rows of the groups other than the central group is reduced, that is, the nozzle openings of the group 204 of FIG. 7 and the nozzle opening row A of the group 210 of FIG. The number becomes 6, which is one less than the other groups that complement the dots in the center, that is, group D in FIG. 7 and group C in FIG.
The nozzle openings belonging to No. 1 are located at the uppermost end and the lowermost end of the recording head.

As a result, the nozzle opening for printing the last line of one row and the nozzle opening for printing the first line of the next row belong to the same group, which further improves the printing quality. It becomes possible.

FIG. 10 shows an embodiment of the ink jet recording head which positively utilizes the fact that the uppermost and lowermost nozzle openings belong to the above-mentioned central group. Particularly, a large number of, for example, 64 nozzle openings are formed in the same nozzle plate, and this is a preferred embodiment for a recording head capable of printing with extremely high density.

In the nozzle opening row of the group 214 arranged in the central portion of the recording head, the nozzle opening 1 located at the uppermost end of the recording head and the nozzle opening 64 located at the lowermost end,
The dots are arranged at the same pitch as in FIG. 1 described above, and accordingly, one of the other groups, that is, the dot that will print the last line if printed in order, in this embodiment, on the right side of the drawing. Number of nozzle openings in group 215 located 6
This is a reduction of 5, 66.

According to this embodiment, the bottommost line of one row is printed by the nozzle opening 64 in the central part, and the topmost printing of the next row is printed by the nozzle opening 1 which also belongs to the central group 214. Not only is it possible to minimize the error in the line spacing before and after feeding the paper due to the tilt of the head, but also when printing the last line of a solid image such as graphics, the upper side of the recording head Even when printing using a part of
Since the nozzle opening 64 that prints the last line of the row immediately preceding the last row and the nozzle opening 1 that prints the uppermost line of the last row belong to the central group 214, the whole is printed with high print quality. be able to.

In the above-mentioned embodiment, the group is formed by one or two rows of nozzle openings, but if one group can be managed as a group, three or more rows of nozzle openings are provided. It is clear that the same effect can be obtained even if the housing is housed.

Further, in the above-described embodiment, the recording head using the flexural vibration of the piezoelectric vibrating plate, which tends to increase the distance between the nozzle opening rows, has been described as an example, but the intervals between the nozzle opening rows are compared. It is obvious that the same effect can be obtained even when applied to a recording head using a longitudinal vibration mode of a piezoelectric vibrator that can be set to a relatively small value.

[0052]

As described above, in the present invention,
A plurality of nozzle openings are formed in the sub-scanning direction, the nozzle opening row divided into three groups at regular intervals in the main scanning direction is provided on the same substrate, and the group of nozzles located at the center in the main scanning direction is provided. The nozzle openings of the other groups arranged on both sides complement the space between the nozzle openings of the group arranged in the central portion, and the nozzle openings of the group arranged in the central portion are located at the uppermost end or the lowermost end. Since the lines printed by the groups arranged on both sides are printed so as to sandwich the lines printed by the group arranged in the central portion, three or more nozzle opening lines are formed. It can be applied regardless of the number of nozzle opening rows as long as it is managed in three groups, so that the lines printed by the groups arranged on both sides are arranged in the central part. It is possible to print by sandwiching the lines printed by a group, and the distance in the main scanning direction of the nozzle openings that print adjacent lines is reduced to about half the maximum distance between the nozzle opening rows to reduce the distance between the lines due to the tilt of the recording head. The print quality can be improved by reducing the positional error and the error between the lines in the sub-scanning direction at the band break before and after the line feed.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an inkjet recording head of the present invention with an array of nozzle openings.

FIG. 2 is a perspective assembly view showing an embodiment of the ink jet recording head of the present invention.

3A and 3B are a cross-sectional view of an inkjet recording head of the present invention and a cross-sectional view showing another embodiment in which the positions of nozzle openings are changed.

4 (a), (b), and (c) show pressure generation by adjusting the positions of the nozzle openings and the positions of the conduction holes that connect the pressure generating chambers in the inkjet recording head of the present invention. It is a figure which shows the Example which changed the position of the nozzle opening with respect to a chamber.

5A and 5B are respectively a print pattern by a recording head adopting an arrangement of nozzle openings of the present invention,
It is a figure which shows the printing pattern by the recording head which took the conventional nozzle opening arrangement.

FIG. 6 is a diagram showing another embodiment of the present invention with an array of nozzle openings.

FIG. 7 is a view showing another embodiment of the present invention with an array of nozzle openings.

FIG. 8 is a diagram showing another embodiment of the present invention with an array of nozzle openings.

FIG. 9 is a diagram showing an arrangement form of the conductive holes suitable for forming the arrangement pitch of the nozzle openings in the same embodiment.

FIG. 10 is a view showing another embodiment of the present invention with an array of nozzle openings.

[Explanation of symbols]

 A to F Nozzle opening row 1 to 30 Nozzle opening 102 Vibrating plate 103 Pressure generating chamber 104 Piezoelectric vibrating plate 109 Conducting hole 110 Common ink chamber 114 Conducting hole 121 Conducting hole 130 Nozzle plate 131 Nozzle opening 201, 202, 203 Nozzle opening row Group of

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B41J 2/13 2/255 B41J 3/04 104 D 3/10 106 K

Claims (6)

[Claims] 1. A plurality of nozzle openings are formed in the sub-scanning direction, and a nozzle opening row divided into three groups at regular intervals in the main scanning direction is provided on the same substrate, and a central portion in the main scanning direction is provided. Nozzle openings of the other group arranged on both sides of the group located in, complement the nozzle openings of the group arranged in the central portion, and the nozzle opening of the group arranged in the central portion is the uppermost end, Alternatively, an ink jet recording head, which is located at the lowest end and is printed by the lines printed by the groups arranged on both sides, sandwiching the line printed by the groups arranged in the central portion. 2. Each group has two rows of nozzle openings, the nozzle openings of the group arranged in the central portion have a pitch of 3 dots in the sub-scanning direction, and another group has the central portion. The ink jet recording head according to claim 1, which has two types of pitches of 1 dot and 5 dots so as to alternately complement the nozzle openings of the group. 3. The nozzle openings of the group arranged in the central portion have a pitch of 2 dots, and the other groups are composed of one nozzle opening row, and the nozzle opening rows of the central portion are arranged between the nozzle opening rows. Nozzle opening is 4 to complement
The ink jet recording head according to claim 1, wherein the ink jet recording head has a dot pitch. 4. The ink jet recording head according to claim 3, wherein the group arranged in the central portion is composed of two rows of nozzle openings. 5. The ink jet recording head according to claim 3, wherein the group arranged in the central portion is constituted by a single nozzle opening row. 6. A plurality of nozzle openings are formed in the sub-scanning direction, and nozzle opening rows divided into three groups at regular intervals in the main scanning direction are provided on the same substrate, and a central portion in the main scanning direction is provided. Nozzle openings of the other group arranged on both sides of the group located in, complement the nozzle openings of the group arranged in the central portion, and the nozzle opening of the group arranged in the central portion is the uppermost end, And an inkjet recording head which is located at the lowermost end and in which lines printed by the groups arranged on both sides are printed with the lines printed by the group arranged in the central portion sandwiched therebetween.