JP2001058422A - Ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a long recording head for multi-color printing suppressed in the expansion of a nozzle orifice arranging width in a main scanning direction in a good production yield, and to provide the recording head enabling high speed recording of high quality. SOLUTION: In a recording head wherein n nozzle orifices are arranged in a row at a pitch Po and linear recording head modules of which the width in the direction right-angled to a nozzle row is (t) are provided by the number corresponding to m kinds of colors to be printed to record scanning lines at a scanning pitch Ps with respect to each of colors, the width (t) of the module of each color is set to (n-1)A/2 m<t<=(n/m)A and the nozzle row of the module is inclined by θ=Sin-1(Ps/Po) with respect to a main scanning direction and a plurality of the muldules of the same color are arranged at an interval nPs in the direction vertical to the main scanning direction and the modules of other (m-1) colors are successively arranged in the interval nPs. m and n are a natural number and A is set to A=Ps/Po(Po2-Ps2)1/2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head for an ink jet recording apparatus, and more particularly to a long ink jet recording for multicolor recording capable of recording a wide band of multicolors in a single scan relative to recording paper. About the head.

[0002]

2. Description of the Related Art In a serial scanning type ink jet recording apparatus for continuous paper according to the prior art, multicolor printing is performed in a transverse direction (paper width direction) crossing a continuous direction (sub-scanning direction) of continuous recording paper (hereinafter referred to as continuous paper). (For example, cyan, magenta,
The recording head is moved (main scanning direction) while ejecting ink (yellow and black four colors) to record a band-shaped multicolor image of one line composed of a plurality of multicolor main scanning lines, and then the recording paper is moved in the sub-scanning direction. Is fed a predetermined amount of paper, and then the main scanning is performed to record the band-shaped multicolor image of the next line. Then, a multicolor image is recorded by repeating the main scanning and the sub-scanning.

In order to increase the recording speed in such a serial scanning type ink jet recording apparatus, it is necessary to increase the number of main scanning lines of each color of the band-shaped multicolor recording which can be recorded per main scanning of the recording head. For this purpose, a multicolor recording long recording head in which multicolor nozzle cells including a large number of nozzle holes are arranged is used.

Further, in the case of a high-speed ink jet recording apparatus, a long multi-color recording line recording head in which nozzle cells for each color having nozzle holes for the number of scanning lines required for recording are arranged over the continuous paper in the width direction. Is used.

As a method of realizing such a long recording head, there is a method of forming a large number of nozzle cells for each color in a line for each color, but this method generally has a low production yield. In addition, if even one of the many nozzle cells has a variation in the ink ejection characteristics, there is a high possibility that the recording dots due to this will cause significant deterioration in print quality.

Therefore, as another method of realizing a long recording head, there is a method of arranging and combining short recording head modules having a good production yield. A long recording head according to this method is disclosed in, for example, Japanese Patent Publication No. 03-5992. In the case of multicolor printing, a method of preparing such a long recording head for each color and arranging them in the main scanning direction has been adopted.

[0007]

The above-mentioned method of arranging and combining a plurality of modules of a short recording head can improve the production yield and can reduce the cost, but has the following problems.

FIG. 4 shows a conventional configuration (left diagram), which is a recording head for performing two-color printing. In order to realize continuity of the nozzle holes in the sub-scanning direction of the recording head, a group of sub-recording head modules S in which a plurality of recording head modules 1 are arranged in the width direction of the recording head is grouped and separated from each other by at least the width. A staggered arrangement is adopted. Note that this staggered arrangement is performed individually for each color.

However, in such a zigzag arrangement of the sub print head modules S, the width (Lj) of the print head in the main scanning direction is inevitably large in mounting, and as a result, the nozzle holes in the main scanning direction have to be large. The array width also becomes wide. Particularly, in a recording head for four-color printing, a staggered arrangement is performed for each color, so that the width must be considerably widened. This causes a problem that the landing position of the recording dot varies depending on the fluctuation of the relative moving speed between the continuous paper and the recording head.

On the other hand, in order to obtain a high-resolution recording head, it is necessary to form a sub-recording head module S by combining a large number of recording head modules 1, which increases the width of the sub-recording head module S. Eventually, the array width (Lj) in the main scanning direction increases, and the array interval of the nozzle holes in the main scanning direction also increases.
Variations in the landing positions of the recording dots become even more serious.

Further, the above-described recording head having a wide array of nozzle holes has a problem in recording speed in addition to a problem in landing position variation. This is particularly serious in a serial scanning type printer.

That is, when recording is performed with a predetermined recording paper width by a serial scanning type ink jet printer, especially in order to perform printing properly at both ends of the recording paper width with a recording head having a large arrangement width of nozzle holes in the main scanning direction, the arrangement is required. This is because it is necessary to perform main scanning for the width.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a multicolor recording long recording head in which the arrangement width of nozzle holes in the main scanning direction is suppressed. It is an object of the present invention to provide a recording head which can be realized and capable of high-quality and high-speed recording with a high production yield.

[0014]

According to a first configuration of the present invention for solving the above-mentioned problems, n nozzle holes are arranged in a row at a nozzle pitch Po, and the width in the direction perpendicular to the nozzle row is set. t to print a plurality of linear recording head modules
In a multi-color printing ink jet recording head for recording the scanning lines of the scanning pitch Ps for each color on the recording paper, the width t of each linear recording head module is set to (n -1) A / 2m
<T ≦ (n / m) A, and the nozzle array of the linear recording head module is θ = Sin ⁻¹ (Ps / Po) with respect to the main scanning direction which is the relative movement direction of the recording head and the recording paper.
And a plurality of linear recording head modules of the same color are arranged at an interval nPs in a direction perpendicular to the main scanning direction, and another linear recording head module of another (m-1) color is arranged between the intervals nPs. Are sequentially arranged. Here, m and n are natural numbers, and A = Ps / Po (Po ² −P
s ² ) ^1/2 .

According to a second aspect of the present invention, there is provided an ink pressurizing chamber having a nozzle hole as an opening end, an ink inflow hole for leading ink to the ink pressurizing chamber, and A plurality of nozzle cells having a manifold for supplying ink to the inflow holes are arranged in a row at a nozzle pitch Po;
This nozzle cell row is used as a virtual linear print head module, and the linear print head module is to be printed.
In a multi-color printing ink jet recording head which is provided with a number corresponding to each kind of color and records the scanning line of the scanning pitch Ps for each color on the recording paper, the width t of the virtual linear recording head module for each color is provided. To (n-1)
A / 2m <t ≦ (n / m) A, and the nozzle row of the virtual linear print head module is θ = S with respect to the main scanning direction which is the relative movement direction of the print head and the print sheet.
in ^-1 (Ps / Po), and a plurality of virtual linear recording head modules of the same color are arranged at an interval nPs in a direction perpendicular to the main scanning direction. (M-1) The virtual linear recording head modules of the colors are sequentially arranged.

In the first or second configuration, the nozzle pitch Po is defined as Po = Ps / Po {(k ² +
1) It is good to set Ph ² } ^1/2 where k is a natural number and Ph
Is a predetermined value of the recording dot pitch in the main scanning direction.

In the ink jet recording head according to claim 1 or 2, preferably, the linear recording head module for printing a predetermined color is provided with another (m).
-1) It is preferable that the linear recording head modules for the colors are arranged so as to be shifted by h · Po / m in the inclination direction of θ so that the printing intervals of the respective colors in the main scanning direction are equal.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an ink jet recording head for two-color recording according to the present invention, in which a surface arranged to face a recording sheet is obliquely directed upward.

This recording head has, for example, a linear recording head module 1X for discharging black ink and a linear recording head module 1Y for discharging red ink. A plurality of these two-color linear recording head modules 1 are alternately arranged. A frame 2 is provided which is arranged and held in a predetermined positional relationship. The linear recording head modules 1X and 1Y of the respective colors have the same structure, and n nozzle holes are formed at the nozzle pitch Po.
And nozzle rows 100 arranged in rows.

FIG. 2 is a partially enlarged view of three rows of the linear recording head module 1 arranged in the frame 2, and is a plan view as viewed from the nozzle hole arrangement surface.

Linear recording head module 1X, 1Y
Are n nozzle cells 1 each having a nozzle hole 10 as an opening.
Consists of 50. The nozzle cell 150 has a nozzle hole 10
Pressurizing chamber 20 having an opening end as the ink pressurizing chamber 2
An ink inflow hole 30 for guiding ink to zero and a manifold 40 for supplying ink to the ink inflow hole 30 are provided. A drive element (not shown) such as a piezoelectric element that changes the volume of the ink pressurizing chamber 20 according to the application of a recording signal is attached to the ink pressurizing chamber 20. Each component is arranged and configured in a three-dimensional manner, for example, in the vertical direction of the drawing. The structure of each nozzle cell is the same. Then, black ink is supplied to the linear recording head module 1X, and red ink is supplied to the linear recording head module 1Y.

The operation of each nozzle cell is as follows.

For example, when ink is ejected from the nozzle holes 10a during recording, first, the volume of the ink pressurizing chamber 20a is increased by a driving element (not shown). Thereby, the ink in the manifold 40a supplied along the arrow A flows through the ink pressurizing chamber 2 through the ink inflow hole 30a.
Flow into 0a. Subsequently, the volume of the ink pressurizing chamber 20a is reduced by the driving element. Thereby, the ink pressurizing chamber 20
The ink in a flows toward the nozzle hole 10a in the direction of arrow B, and the ink is ejected from the nozzle hole 10a. The discharged ink lands on the recording paper in the process of scanning the recording head relative to the recording paper, and forms a recorded image. According to the above-described ejection principle, black ink is ejected from the linear recording head module 1X according to the recording signal, and red ink is ejected from the linear recording head module 1Y according to the recording signal. , Two-color recording images are obtained.

FIG. 3 is an explanatory diagram showing the size and arrangement of the linear recording head module of the recording head according to the present invention.

Each of the linear recording head modules 1X and 1Y has a width t, and n (six in FIG. 3) nozzle holes 10 are arranged at a pitch Po. The width t is set as follows. The derivation of this equation will be described later.

[0027]

(Equation 1)

Further, the linear recording head module 1
X and 1Y indicate that the nozzle array direction is an angle with respect to the main scanning direction.
It is arranged at an angle θ. This inclination angle is θ = S
in ^-1(Ps / Po). Here, Ps is the value of the recording head.
With the pitch (resolution) of the scanning line printed in one main scan
is there. In addition, the linear recording
There are N recording head modules 1X, nPs in the sub-scanning direction.
They are arranged at intervals. Furthermore, each linear recording head module
Module 1X, N linear recording head modules
1Y are individually arranged.

According to the recording head of the present invention described above, the black scanning line of the pitch Ps can be recorded by the black discharge ink from each nozzle hole of the linear recording head module 1X. Further, a red scanning line of the pitch Ps can be recorded by red ink discharged from each nozzle hole of the linear recording head module 1Y. The recording width is almost N
× (n × Ps), and a long recording head can be realized by increasing the number N of arrangements of the linear recording head modules 1. As described above, in the present recording head, since the long recording head can be constituted by a small linear recording head module having a relatively small nozzle cell and a good production yield, it can be realized with a high yield as a whole.

FIG. 4 shows a comparison between a recording head according to the present invention and a conventional recording head constructed by arranging linear recording head modules 1 in a conventional manner in order to enable recording at the same scanning pitch Ps. It is shown. The conventional linear recording head modules 1X, 1X,
Y and the head size and ink discharge characteristics of the linear recording head module 1 of the present invention are all the same.

In the figure, two colors (m colors) according to the conventional configuration are shown.
In the recording head for recording, in order to realize the scanning pitch Ps, two recording head modules 1X and 1Y are arranged in the main scanning direction (2m in the case of m color) and are arranged while being shifted in the main scanning direction. Sub-modules S are organized. Then, in order to realize continuity of the nozzle holes in the longitudinal direction of the recording head, the recording head sub-module S is separated in the width direction (main scanning direction) of the recording head from the recording head sub-module in a staggered manner. The nozzles are arranged alternately, and the arrangement width Lj of the nozzle holes in the main scanning direction is large.

On the other hand, in the recording head according to the present invention, the arrangement width Lh of the nozzle holes in the main scanning direction is
Arrangement width of nozzle holes in the main scanning direction of print head of conventional configuration
It is narrower than Lj and can be reduced to about 1/2 at the maximum.

Here, a method for deriving the upper and lower limits of the width t of the recording head module 1 will be described.

First, in FIG. 3, triangles A and B
Is a similar right triangle having an acute angle θ, so that t ₁
/ T ₁ = y / Po. Therefore, T ₁ = t ₁ × Po / y
(Equation 1) is obtained. On the other hand, since the right triangle C having the acute angle θ is similar to the triangle B, t ₂ / T ₂ = y / Po, and T ₂ = t ₂ × Po / y (Equation 2) is obtained.

Here, in a recording head composed of a plurality of colors m, the distance between nozzle holes at the same position in the sub-scanning direction of adjacent recording head modules 1 of the same color is (n / n).
m) Ps, and if this distance is smaller than T ₁ + T _{2 in} FIG. 3, the recording head modules are arranged adjacently, so that T ₁ + T ₂ ≦ (n / m) Ps ( Equation 3) is obtained. From (Equation 1) and (Equation 2), T ₁ +
Since T ₂ = (t ₁ + t ₂ ) × Po / y = t × Po / y, when this is introduced into (Equation 3), t × Po / y ≦ (n
/ M) Ps (Equation 4) is obtained.

Therefore, t is as follows. Note that y
= A (Po ² -Ps ^{2) 1/2.}

[0037]

(Equation 2)

On the other hand, as shown in FIG. 4, in the conventional configuration, the recording head sub-module S has a scanning pitch P with respect to the distance Po between the nozzle holes of the recording head module 1.
The number of Po / Ps is arranged to be s. Further, assuming that the distance from another print head submodule S arranged in a staggered manner is t / 3 for convenience, the total width Lj of the print head of the conventional configuration is 2m × Po / Ps × t (Equation 5). .

On the other hand, in the recording head of the present invention,
The total width Lh is (n-1) (Po ^Two-Ps^Two)^1/2so
is there. This total width Lj is the total width of the recording head having the configuration of the present invention.
Is the configuration of the present invention advantageous when it is larger than Lh?
2m × Po / Ps × t> (n−1) (Po^Two−P
s^Two)^1/2And finally as follows.

[0040]

(Equation 3)

From [Equation 2] and [Equation 3], the upper and lower limits of the width t of the recording head module 1 are as follows.

[0042]

(Equation 4)

That is, at t = (n / m) A, this shortening rate becomes maximum, and at t = (n-1) A / 2m, L _h
= L _j .

In the above description, the distance l between the recording head sub-modules S and the adjacent recording head module S is assumed to be equal to the width t of the head module 1, but when l = 0. However, the effect of the present invention is still obtained.

As described above, according to the recording head of the present invention,
It is possible to realize a recording head in which the arrangement width of the nozzle holes in the main scanning direction is narrow, and it is possible to reduce the problem of variation in landing positions of ink droplets due to fluctuation in the speed of main scanning. Further, in particular, in the case of application to a serial scanning type printer, it is not necessary to perform extra scanning by an amount corresponding to the decrease in the arrangement width of the nozzle holes, so that the recording speed can be substantially improved.

In the above example, in order to make the illustration easy to understand, the recording head module has six nozzle holes, Po and Ps.
Is described as being 4: 1, but this value does not limit the present invention.

FIG. 5 is a modification of the above-described example. In other words, the linear recording head module 1Y is shifted from the linear recording head module 1X in the θ direction by Po / 2 toward the lower left side in the drawing. Conversely, it may be shifted to the upper right.

In this configuration, the red scanning lines recorded by the linear recording head module 1Y are recorded between the black scanning lines recorded by the linear recording head module 1X, and the red and black scanning lines are arranged at a pitch Pr. Will be recorded. Accordingly, it is possible to suppress color mixture at the time of ink ejection of two colors of ink or on recording paper, and to improve recording quality.

FIG. 6 shows a linear recording head module 1X, 1Y having 64 nozzle holes n, a nozzle hole pitch Po = 6/300 inches and a thickness t of 5 mm for θ of about 19.47. This is an example in which a plurality of recording head modules 1X and 1Y are arranged side by side.
A main scanning line can be recorded at 1/150 inch. That is, it is possible to print two colors at 150 dpi in one main scan, and it can also be used for a serial scanning type printer. However, when the recording dot density Pr on the recording paper is 150 dpi, a long recording paper width is required. By configuring the line recording head, it becomes suitable as a long recording head for two-color recording for a high-speed line printer.

Further, by constructing a 300 dpi serial printer, it is easy to devise interlaced scanning, and it is possible to achieve an improvement in image quality.

Further, by setting the nozzle hole pitch Po according to the following formula, when recording is performed at a recording dot density of 300 dpi in the main scanning direction, when the dots are aligned in the sub-scanning direction, the nozzle cell shown in FIG. The drive timings of 150 can be aligned, and the drive timing circuit can be simplified. Here, k is a natural number, Ph
Is a value determined by a predetermined value of the recording dot pitch in the main scanning direction, and is set to about 0.515 mm when k = 6 and Ph = 1/300 inch.

[0052]

(Equation 5)

FIG. 7 shows a linear recording head module 1X, 1Y, 1Y for a three-color recording head according to the present invention.
It is a figure showing the size and arrangement of Z.

In the figure, the linear recording head modules 1X (black), 1Y (red), and 1Z (blue) have a width t.
And n (six in the case of FIG. 3) nozzle holes 10 are arranged at a pitch Po. Further, the width of t is (n
−1) / 3 × A / 2 <t ≦ (n / 3) A Incidentally, A = Ps / Po (Po 2 -Ps 2) ^1/2.

Each linear recording head module 1
X, 1Y and 1Z are arranged such that the direction of the nozzle row is inclined by an angle θ with respect to the main scanning direction. This angle is a value defined by θ = Sin ⁻¹ (Ps / Po).

Of the linear recording head modules 1X, 1Y and 1Z having the same structure arranged as described above, N linear recording head modules 1X are provided in the main scanning direction and the relative moving direction of the recording paper. Are arranged at intervals of nPs. The linear recording head modules 1Y and 1Z are arranged between the linear recording head modules 1X.

According to the recording head of this embodiment, black scanning lines at the pitch Ps can be recorded by discharging black ink droplets from each nozzle of the linear recording head module 1X. Similarly, the linear recording head module 1Y
, And blue scanning lines can be recorded at a pitch Ps by the linear recording head module 1Z.

Further, the linear recording head module 1Z
Are arranged in the lower left direction θ with respect to the linear recording head module 1Y by Po / 3, and the linear recording head module 1X is Po in the upper right direction θ with respect to the linear recording head module 1Y. Are shifted by / 3. As a result, the black scanning lines printed by the linear recording head module 1X, the red scanning lines printed by the linear recording head module 1Y, and the blue scanning lines printed by the linear recording head module 1Z are equally spaced. Recording is performed at the pitch Pr. Accordingly, it is possible to suppress color mixing at the time of ink ejection of three colors of ink or on recording paper, and to improve recording quality.

FIGS. 8 and 9 show another example of the two-color recording head of the present invention.

1 and 2, the recording head modules 1 are not completely separated from each other as in the example shown in FIGS. 1 and 2. For example, the nozzle holes 11 are formed in one long orifice 210, and A nozzle row 110 is formed. Further, the ink pressurizing chamber 120 and the manifold 140 are not formed in a module structure but are formed in a lump of patterned long plates, and the long laminated plate 220 is attached below the orifice plate 210. On the other hand, the drive elements that change the volume of the ink pressurizing chamber 120 in accordance with the recording signal are configured as a black ink discharge drive element module 300X and a red ink discharge drive element module 300Y for each nozzle row 110, 220 and are pasted.

In this example, when the drive element module is configured to be long, the yield is particularly deteriorated. However, even if other functional parts such as the nozzle hole are formed to be long, there is no problem in manufacturing, particularly when the yield is satisfactory. It is suitable.

Although high-quality recording requires high nozzle hole arrangement accuracy, in the present embodiment, for example, etching or press punching on a single plate, or laser processing or electroforming, etc. In some cases, the hole can be formed, which is more advantageous in manufacturing than the above-described configuration in which the recording head module 1 is incorporated into a frame.

In the examples shown in FIGS. 8 and 9, only the driving element has a module configuration. However, the present invention is not limited to this driving element. Only the elements are modularized,
By collectively configuring the other components, it is possible to manufacture the recording head satisfactorily without yield.

In the above example, the case where any of the nozzle components is modularized has been described. The two-color recording heads shown in FIGS. 10 and 11 to be described next show an example in which nozzle components are long and can be produced with high yield, that is, there is no concern about yield without using a module configuration.

A long orifice plate 210 having nozzle holes, which are nozzle components, a long laminated plate 220 in which the ink pressurizing chamber 120 and the manifold 140 are formed, and a long drive element integrated plate 310 are laminated. , A long recording head.

When the configuration of this example is compared with the configuration described above, a virtual linear recording head module 400X in which the nozzle cells 150 having the n nozzle holes 11 as openings are arranged in a row at the nozzle pitch Po, 400Y can be found. This virtual linear recording head module 4
By applying a plurality of arrangement methods in the longitudinal direction to the width t and the inclination θ of the linear recording head module described in the previous example with respect to 00X and 400Y, the nozzle arrangement width in the main scanning direction can be suppressed to be narrow. Thus, the object of the present invention can be achieved.

In the above description, a case has been described in which the nozzle hole rows of the linear recording head module are formed in a single row on a straight line. The objects of the present invention can be achieved if they can be arranged in rows within the width.

In each of the above-described examples, the ink jet recording method has been described as a recording method. However, the recording method is not limited to the ink jet recording method, and other recording methods such as a thermal recording method and a wire dot recording method in which a large number of recording cells are arranged and recorded. It can also be applied to a recording head of the system.

[0069]

According to the present invention, it is possible to realize a recording head for multicolor printing having a narrow arrangement width of the nozzle holes in the main scanning direction with a high production yield, and a variation in landing positions of ink particles due to fluctuations in the speed of main scanning. Problem can be reduced, and high-quality recording becomes possible. Further, when the present invention is applied to a serial scanning type printer, it is not necessary to perform additional scanning by an amount corresponding to the decrease in the arrangement width of the nozzle holes, so that it is possible to substantially improve the recording speed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ink jet recording head as an example of the present invention.

FIG. 2 is an enlarged view of a main part of the recording head of FIG. 1;

FIG. 3 is a conceptual diagram for explaining dimensions and arrangement of a recording head according to the present invention.

FIG. 4 is a configuration comparison diagram of the recording head of the present invention and a conventional recording head.

FIG. 5 is a configuration diagram of a recording head according to another example of the invention.

FIG. 6 is a configuration diagram of a recording head according to another example of the invention.

FIG. 7 is a configuration diagram of a recording head according to another example of the invention.

FIG. 8 is a perspective view of an ink jet recording head as another example of the present invention.

FIG. 9 is an enlarged view of a main part of the recording head of FIG. 8;

FIG. 10 is a perspective view of an ink jet recording head as another example of the present invention.

FIG. 11 is an enlarged view of a main part of the recording head of FIG. 10;

[Explanation of symbols]

1 is a linear recording head module, 2 is a frame, 10, 1
0a and 11 are nozzle holes, 20 is an ink pressurizing chamber, 30 is an ink inlet, 40 and 140 are manifolds, 100 is a nozzle row, 110 is an orifice hole, 120 is an ink pressurizing chamber, 130 is an ink inlet, 150 Is a nozzle cell, 21
Reference numeral 0 denotes an orifice plate, 220 denotes a long laminated plate, 300 denotes a drive element module, and 310 denotes a drive element integrated board. A and B indicate the direction of ink flow.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshitaka Ogawa 1060 Takeda, Hitachinaka, Ibaraki Prefecture Inside Hitachi Koki Co., Ltd. (72) Inventor Satoru Tobita 1060 Takeda, Hitachinaka City, Ibaraki Prefecture Inside Hitachi Koki Co., Ltd. (72) Inventor Osamu Machida 1060 Takeda, Hitachinaka-city, Ibaraki Pref.Hitachi Koki Co., Ltd. (72) Inventor Katsunori Kawasumi 1060 Takeda, Hitachinaka-shi, Ibaraki Pref.Hitachi Koki Co., Ltd. Address Hitachi Koki Co., Ltd. (72) Inventor Mamoru Okano 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi Ltd. 2C056 EA01 EA04 EA11 EA24 EE08 HA07 HA22

Claims (4)

[Claims] An n number of nozzle holes are arranged in a row at a nozzle pitch Po, and a plurality of linear recording head modules whose width in a direction perpendicular to the nozzle row is t correspond to m kinds of colors to be printed. And an ink jet recording head for multi-color printing for recording the scanning line of the scanning pitch Ps for each color on the recording paper, wherein the width t of each linear recording head module is set to (n-1).
A / 2m <t ≦ (n / m) A, and the nozzle row of the linear recording head module is θ = Sin with respect to the main scanning direction which is the direction of relative movement between the recording head and recording paper.
^-1 (Ps / Po), and a plurality of linear recording head modules of the same color are arranged at an interval nPs in a direction perpendicular to the main scanning direction.
-1) An ink jet recording head in which color linear recording head modules are sequentially arranged. However,
m, n are natural numbers, and ^{A = Ps / Po (Po 2} -Ps 2) 1/2. 2. An ink pressurizing chamber having a nozzle hole as an opening end,
N nozzle cells each having an ink inflow hole for guiding ink to the ink pressurizing chamber and a manifold for supplying ink to the ink inflow hole are arranged in a row at a nozzle pitch Po, and this nozzle cell row is virtually linearly recorded. An ink jet recording head for multicolor printing, wherein a head module is provided, and the linear recording head modules are provided in a number corresponding to m kinds of colors to be printed, and a scanning line of a scanning pitch Ps is recorded on recording paper for each color. The width t of the virtual linear recording head module for each color
(n-1) A / 2m <t ≦ (n / m) A, and the nozzle row of the virtual linear print head module is θ with respect to the main scanning direction which is the relative movement direction between the print head and the print sheet. = Sin ^-1 (Ps / Po), and a plurality of virtual linear recording head modules of the same color are arranged at an interval nPs in a direction perpendicular to the main scanning direction. (M-1) virtual linear print head modules are sequentially arranged. Where m and n are natural numbers and A = P
^{s / Po (Po 2 -Ps 2} ) and ^1/2. 3. The ink jet recording head according to claim 1, wherein the nozzle pitch Po is expressed as Po = Ps / Po {(k ² +1).
An ink jet recording head characterized in that Ph ² } ^1/2 . Here, k is a natural number, and Ph is a predetermined value of the recording dot pitch in the main scanning direction. 4. The ink jet recording head according to claim 1, wherein a linear recording head module of another (m-1) color is tilted in the inclination direction of θ with respect to the linear recording head module for printing a predetermined color. An ink jet recording head, wherein the ink jet recording heads are arranged so as to be shifted by h · Po / m at equal intervals in the main scanning direction for each color. Here, h is a natural number.