JPH0615844A - Ink jet printer - Google Patents

Abstract

PURPOSE:To prevent the color mixture of inks and to miniaturize a multicolor recording head by arranging the nozzle orifice rows of the recording head at least in two rows and alternately supplying water-soluble ink and water- insoluble ink to the nozzle orifice rows. CONSTITUTION:In an ink jet printer, ink is emitted and injected from the nozzle orifices 14 of a recording head to form flying liquid droplets to record a dot image on a recording medium. A recording head is formed by bonding passage sealing substrates 11, 12 to a passage forming substrate 10 and bonding piezoelectric elements to the passage sealing substrate 11 at the positions 13 thereof and bonding piezoelectric elements to the passage sealing substrate 12. Nozzle orifice rows are arranged on the passage forming substrate 10 at least in two rows and, for example, nine nozzle orifices 14 are arranged to each of the rows. Water-soluble ink based on a water-soluble dye and a water-soluble solvent and water-insoluble ink based on an oily dye and a water-insoluble solvent are alternately supplied to the nozzle orifice rows. Further, water-insoluble ink is selected so as not to generate color mixture in matching relation to the physical property control agent added to the water-soluble ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-demand type ink jet printer, and more particularly to a multi-color ink jet printer using colors such as black, yellow, magenta and cyan.

[0002]

2. Description of the Related Art Conventionally, a multi-color ink jet printer has a plurality of recording heads, and the inks of respective colors are not mixed on the recording heads by the means (1) to (3) below. ) Was realized.

(1) In Japanese Patent Laid-Open No. 58-194568, as shown in FIG. 12, a plurality of recording heads 121, 122, 1
23, 124, a plurality of sealing ports 126, 127, 128 for sucking ink into the elastic cap 125,
129 was provided for each recording head.

(2) In JP-A-60-159057, as shown in FIG. 13, a cap 131 and a suction pump 132 are provided.
An electromagnetic valve 133 for preventing color mixing was provided in the middle of the suction path between them.

(3) In Japanese Patent Laid-Open No. 62-251146, a plurality of cleaning brushes 146, 147, 148 corresponding to a plurality of recording heads 142, 143, 144, 145 are arranged along an endless belt 141 as shown in FIG. 149
And a wiping means for dividing the wiping operation range of each cleaning brush for each recording head.

[0006]

However, the above-mentioned conventional technique has a drawback that the recording head becomes large because it has a plurality of recording heads for the purpose of multicoloring of the ink jet printer. Further, in order to prevent color mixture of inks of a plurality of colors, it is necessary to provide a plurality of the above-mentioned members corresponding to the heads for the respective colors, and the size of the multicolor ink jet printer becomes large. .

Therefore, the present invention has been made to solve such a drawback as a result of the extensive researches by the authors over the years, and prevents the color mixture due to the physical properties of the ink, and from this, it is dedicated to each color. An object of the present invention is to provide a multi-colored printer without a head unit and a pump unit, to downsize a recording head, and to provide a smaller inkjet printer.

[0008]

The ink jet printer of the present invention is an ink jet printer for forming ink droplets by ejecting ink from a nozzle hole of a recording head to record a dot image on a recording medium. At least two nozzle hole rows of the head are arranged so that the water-soluble ink and the non-water-soluble ink are alternately supplied to the nozzle hole rows.

An ink jet printer characterized in that inks of different colors are supplied to the at least two or more nozzle hole arrays.

[0010]

According to the above configuration of the present invention, water soluble inks hydrophilic material (hydrophilic group: -OH, -COOH, -NH _2,
A contains many -SO ₃ H), non-water soluble ink is a hydrophobic material (hydrophobic group: -C _n H _{2n + 1} for a a contains many), water-soluble ink is hydrophilic substance Even if the water-insoluble ink, which is a hydrophobic substance, is used on one recording head substrate, it does not mix so as to be so-called “water and oil do not mix”.

[0011]

EXAMPLES The present invention will be described below based on examples.

First, the basic composition of the water-soluble ink used in the present invention is, firstly, a water-soluble dye and secondly a water-soluble solvent. As the water-soluble dye, C.I. I. Di
rect Black (DBk) -19, DBk-
38, DBk-71, DBk-74, DBk-75, D
Bk-90, DBk-112, DBk-117, DBk
-154, Acid Black (hereinafter ABk) -2,
There are ABk-24, ABk-31, ABk-52 and the like.
As a color dye, C.I. I. DirectYell
ow (hereinafter DY) -27, DY-28, DY-33, D
Y-39, DY-58, DY-86, DY-88, DY
-98, Acid Yellow (hereinafter AY) -11,
AY-17, AY-25, Direct Red (hereinafter D
R) -1, DR-2, DR-4, DR-9, DR-1
1, DR-13, DR-17, DR-20, Acid
Red (hereinafter AR) -1, AR-32, AR-51, D
direct Blue (hereinafter DB) -1, DB-8, D
B-71, DB-76, DB-78, DB-80, DB
-86, DB-90, Acid Blue (hereinafter AB)
-9, AB-22, AB-93 and the like, but not limited to these.

As a solvent, a mixture of water (deionized water or pure water) and various water-soluble organic solvents is used as a main liquid medium component. The water-soluble organic solvent does not mix with the main solvent of the non-water-soluble ink, has a low vapor pressure and is difficult to evaporate and dry, polyethylene glycol, polyalkylene glycols such as polypropylene glycol, alkylenes such as ethylene glycol and triethylene glycol. Examples include polyhydric alcohol solvents such as glycols and glycerin.

In addition to the above components, various additives can be used to further optimize the physical properties and improve the properties. For example, it is a viscosity modifier, an antifungal agent and the like.

The content of the water-soluble organic solvent in the ink of the present invention is in the range of 0 to 70% by weight, more preferably 5 to 40% by weight, based on the total weight of the water-soluble ink. or,
The content of water is 10 to 9 relative to the total weight of the water-soluble ink.
It is desirable that the amount is 0% by weight, and more preferably 40 to 85% by weight. The content of the water-soluble dye, which is a colorant, is 0.1 to 10% by weight based on the total weight of the water-soluble ink,
It is more preferably in the range of 0.5 to 5% by weight.

The basic composition of the water-insoluble ink used in the present invention is firstly an oil dye and secondly a water-insoluble solvent. As the oil-based dye, C.I. I. So
lvent Black (hereinafter SBk) -3, SBk-
7, SBk-22, SBk-45, SBk-50 and the like. As a color dye, C.I. I. SolventY
ellow (hereinafter SY) -19, SY-61, SY-8
2, SY-93, Solvent Red (hereinafter SR)
-8, SR-18, SR-49, SR-81, Solv
ent Blue (hereinafter SB) -2, SB-5, SB-
36, SB-70, Solvent Violet (hereinafter referred to as SV) -21, and the like, but are not limited thereto.

Examples of the solvent include aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ether solvents, ketone solvents, ester solvents, fatty acid solvents, nitrogen compound solvents, silicones. Oil, etc.
Any of them can be used alone or in a mixture of two or more kinds. However, it is necessary to select in accordance with the physical property modifier added to the water-soluble ink so that the water-soluble ink and the water-insoluble ink do not mix.

In addition to the above components, various additives can be used in order to further optimize the physical properties and improve the properties. For example, it is a viscosity modifier, an antifungal agent and the like.

In the present invention, the above solvent and oily dye are contained,
Desirably, the content of the solvent is in the range of 50 to 99 wt% with respect to the total weight of the water-insoluble ink, and the content of the oil-based dye as a colorant is in the range of 1 to 30 wt% with respect to the total weight of the water-insoluble ink. Is desirable.

Now, the present invention will be described in more detail with reference to the examples of the ink jet printer using the water-soluble ink and the water-insoluble ink, and the effects will be illustrated together.

[Embodiment 1] FIG. 1 is a view showing an embodiment of an ink jet printer of the present invention, in which two nozzle hole rows are provided.
FIG. 3 is a perspective view of a plastic (polycarbonate) recording head having rows and nine nozzle holes arranged in each row. The array of such nozzle hole rows will be referred to as "2 rows x 1".

In the figure, 10 is a flow path forming substrate A manufactured by molding with polycarbonate, 11 is a flow path sealing substrate a, and 12 is a flow path sealing substrate b. 11 and 12 are sheet-shaped polycarbonates, both having a thickness of 0.15 m
m. 13 is a position where a piezoelectric element (not shown) is adhered when the flow path sealing substrate a is welded to the flow path forming substrate A, and 14 is a nozzle hole. Although not shown, the piezoelectric element is also bonded to the flow path sealing substrate b. The nozzle hole 14 has a trapezoidal shape with a short side of 60 μm, a long side of 70 μm, and a height of 30 μm, and the nozzle pitch is 350 μm. Reference numeral 15 is a cap, which moves in the direction of the arrow and seals the tip of the nozzle hole 14.

Next, the composition of the ink and the manufacturing method thereof will be described.

The water-soluble black ink is prepared by mixing the following components and
The mixture was sufficiently stirred while being heated at 0 ° C., cooled to room temperature, and then pressure-filtered using a membrane filter having a hole diameter of 0.45 μm to manufacture.

Colorant: DBk-19 3.0 wt% Solvent: Glycerin 17.0 wt% Water 80.0 wt% Non-water soluble magenta ink is mixed with the following components at 80 ° C.
The mixture was sufficiently stirred while being heated at room temperature, cooled to room temperature, and then filtered using a membrane filter having a hole diameter of 0.45 μm.

Colorant: SR-49 10.0 wt% Solvent: Oleic acid 40.0 wt% Silicone oil 10.0 wt% n-Dodecane 40.0 wt% The water-soluble ink and the non-water-soluble ink thus produced are The ink was supplied to the inkjet printer of the present invention, and the piezoelectric element was driven to eject and eject ink droplets from the nozzle hole 14 for recording. The driving voltage of the piezoelectric element is 35 V at room temperature and the frequency is 2.0 kHz.

The nozzle hole 1 of the recording head during recording
4 was observed using a microscope, the water-soluble black ink 41 and the non-water-soluble magenta ink 42 did not mix with each other, as shown in FIG. A boundary 43 with the water-soluble magenta ink 42 was formed.

The ink is evenly wet around the nozzle holes 14. Therefore, as shown in the conceptual diagram of the flying state of the ink droplet during recording in FIG.
1. The magenta ink droplet 52 flew without bending vertically to the end surface 54 of the flow path forming substrate A20, the flow path sealing substrate a21, and the flow path sealing substrate b22.

Further, the two colors of ink were not mixed on one recording head substrate, and the result of printing on the recording medium was not mixed.

Further, when printing was performed after cleaning using the cap 15, no color mixture of ink was observed on the recording medium.

[Embodiment 2] FIG. 2 is a view showing another embodiment of the ink jet recording apparatus of the present invention. There are two rows of nozzle holes, and a glass in which 12 nozzle holes are arranged in each row. It is a perspective view of a recording head.

In the figure, reference numeral 20 is a flow path forming substrate B manufactured by etching glass. 21 is a flow path sealing substrate c, 2
Reference numeral 2 denotes a flow path sealing substrate d, both of which are glass plates having a thickness of 0.2 mm. 23, the flow path sealing substrate c is the flow path forming substrate B
Numeral 24 is a nozzle hole at which a piezoelectric element (not shown) is bonded to the nozzle. Although not shown, the piezoelectric element is also bonded to the flow path sealing substrate d. The nozzle holes 24 have a rectangular shape with a width of 50 μm and a height of 30 μm, the number of nozzle holes in one nozzle hole row is 12, and the nozzle pitch is 260 μm. Reference numeral 25 is a cap, which moves in the direction of the arrow and seals the tip of the nozzle hole 24.

Next, the composition of the ink and the manufacturing method thereof will be described.

A water-soluble magenta ink was prepared in the same manner as in Example 1 by mixing the following components.

Colorant: DR-9 2.0 wt% Solvent: Glycerin 6.0 wt% Polyethylene glycol # 200 11.0 wt% Water 81.0 wt% Water-insoluble black ink was mixed with the following components, and Example 1 was used. It was manufactured in the same manner as.

Colorant: SBk-45 15.0 wt% Solvent: Caprylic acid 40.0 wt% Silicone oil 20.0 wt% n-Dodecane 25.0 wt% The water-soluble ink and the non-water-soluble ink thus produced are The ink was supplied to the ink jet printer of the present invention, and the piezoelectric element was driven to eject and eject ink droplets from the nozzle holes 24 for recording. The driving voltage of the piezoelectric element is 110V at room temperature,
The frequency is 2.4 kHz.

The nozzle hole 2 of the recording head during recording
4 was observed using a microscope, the water-soluble magenta ink 61 and the non-water-soluble black ink 62 did not mix with each other, as shown in FIG. A boundary 63 with the water-soluble black ink 62 was formed.

The ink is uniformly wet around the nozzle holes 24. Therefore, as shown in the conceptual diagram of the flying state of the ink droplets during recording in FIG. 7, the ejected magenta ink droplets 61 and the black ink droplets 62 are the flow passage forming substrate B20, the flow passage sealing substrate c21, It flew without bending perpendicularly to the end surface 73 of the flow path sealing substrate d22.

Further, the two colors of ink were not mixed on one recording head substrate, and the result of printing on the recording medium was not mixed.

Further, when printing was performed after cleaning with the cap 25, no color mixture of ink was found on the recording medium.

[Embodiment 3] FIG. 3 is a view showing another embodiment of the ink jet recording apparatus of the present invention. There are two rows of nozzle holes, and nine nozzle holes are arranged in each row. It is a perspective view when two recording heads made of (polysulfone) are arranged. Such an array of nozzle hole rows is “2
Column × 2 ”. Then, by arranging the nozzle hole rows as “2 rows × 2”, three colors or four colors can be obtained.
Colored inks can be used.

The material and the manufacturing method when the two recording heads are lined up may be the same as in this embodiment, or may be different.

In the figure, 30 is a flow path forming substrate C manufactured by molding with polysulfone, 31 is a flow path forming substrate D manufactured by the same material and manufacturing method as 30, and 32 is a flow path sealing substrate. e and 33 are flow path sealing substrates f, 34 is a flow path sealing substrate g, and 35 is a flow path sealing substrate h. The channel sealing substrates 32 to 35 are sheet-like polysulfones, and the thickness of all four sheets is 0.15 mm. 36 is a position to which a piezoelectric element (not shown) is bonded when the flow path sealing substrate e is welded, and 37 and 38 are nozzle holes. Although not shown, the piezoelectric element is also bonded to the flow path sealing substrate f, the flow path sealing substrate g, and the flow path sealing substrate h. The nozzle holes 37 and 38 have a trapezoidal shape with a short side of 60 μm, a long side of 70 μm, and a height of 30 μm. The number of nozzle holes in one nozzle hole row is 9, and the nozzle pitch is 350 μm. Reference numeral 39 is a cap, which moves in the direction of the arrow and seals the tips of the nozzle holes 37 and 38. A spacer 300 is a butyl rubber having a short side of 0.5 mm, a long side of 10.5 mm, and a thickness of 1 mm. The spacer is included in the protruding portion of the recording head, but is not limited to this size as long as it does not hinder the bending of the piezoelectric element. The spacer material may be rubber other than butyl rubber, plastic, glass, or the like. Two
By inserting a spacer 300 between two recording heads to eliminate a space and flatten the surface of the nozzle hole, ink is sucked by one cap that is not divided for each color.

Next, the composition of the ink and the manufacturing method thereof will be described.

A water-soluble black ink was prepared in the same manner as in Example 1 by mixing the following components.

Colorant: ABk-109 3.0 wt% Solvent: Polyethylene glycol # 200 20.0 wt% Water 77.0 wt% The water-soluble magenta ink was mixed with the following components, and Example 1 was used.
It was manufactured in the same manner as.

Colorant: DR-11 3.0 wt% Solvent: Glycerin 20.0 wt% Water 76.5 wt% A water-insoluble yellow ink was prepared in the same manner as in Example 1 by mixing the following components.

Colorant: SY-61 10.0 wt% Solvent: Oleic acid 40.0 wt% Silicone oil 10.0 wt% n-Dodecane 40.0 wt% Non-water-soluble cyan ink was mixed with the following components, 1
It was manufactured in the same manner as.

Colorant: SB-5 10.0 wt% Solvent: Oleic acid 40.0 wt% Silicone oil 10.0 wt% n-Dodecane 40.0 wt% Black ink 81 which is a water-soluble ink produced in this manner,
Each of the magenta ink 83, the yellow ink 82 that is a water-insoluble ink, and the cyan ink 84 was supplied to the four nozzle hole arrays of the recording head.

Further, between the two recording heads, the facing piezoelectric elements do not come into contact with each other (do not energize), and to the facing cavities generated by the deflection of the piezoelectric elements when the ink droplets are ejected. Butyl rubber is used as an insulating pressure absorbing member (not shown in FIG. 3 because it is not visible in FIG. 3) so as to absorb the pressure. As the material of the insulating pressure absorbing member, rubber other than butyl rubber, foam, etc. may be mentioned. It is preferable that the distance between the recording heads is narrow for miniaturization.

Further, the protrusion of the recording head as shown in FIG. 11 and the respective spacers between the two recording heads may be integrated. The spacer 110 is not limited to the shape shown in FIG. 11, and it is sufficient that the nozzle hole surface is flat and the piezoelectric elements facing each other of the two recording heads are not in contact with each other.

Then, the piezoelectric element is driven to drive the nozzle hole 3
Recording was performed by ejecting and ejecting ink droplets from Nos. 7 and 38. The driving voltage of the piezoelectric element is 35 V at room temperature and the frequency is 2.0 kHz.
Is.

The nozzle hole 3 of the recording head during recording
When the periphery of Nos. 7 and 38 was observed using a microscope, FIG.
As shown in a perspective view around the nozzle holes of the recording head, a water-soluble black ink 81 and a water-insoluble yellow ink 82, a water-insoluble yellow ink 82 and a water-soluble magenta ink 83,
Water-soluble magenta ink 83 and water-insoluble cyan ink 84
Of the water-soluble black ink 81 and the water-insoluble yellow ink 8 on the recording head substrate without being mixed with each other.
5. A boundary 86 was formed between the water-soluble magenta ink 83 and the water-insoluble cyan ink 84.

Ink is uniformly wet around the nozzle holes 37 and 38. Therefore, as shown in FIG. 9 showing a conceptual diagram of the flying state of the ink droplet during recording, the ejected black ink droplet 91, yellow ink droplet 92, and magenta ink droplet 9 are ejected.
3, the cyan ink droplet 94 includes the flow path forming substrate C30, the flow path forming substrate D31, the flow path sealing substrate e32, and the flow path sealing substrate f.
33, the flow path sealing substrate g34, and the flow path sealing substrate h35 flew without bending perpendicularly to the end surface 95.

Further, the inks of respective colors were not mixed on one recording head substrate, and the result of printing on the recording medium was not mixed.

Further, as shown in FIG. 10, when printing was performed after cleaning was performed by using one cap 39 which was not divided for each color, no color mixture of ink was found on the recording medium. Similarly to the cap 39, the caps 15 and 25 used in the above-described first and second embodiments are not separated for each color.

In Examples 1 to 3, the number of nozzle holes was 9 or 12 and the nozzle pitch was 350 μm or 260 μm.
However, the present invention is not limited to these. Further, although polycarbonate, polysulfone, and glass are mentioned as the material of the recording head, the recording head is not limited to these, and polyether sulfone, polyallyl sulfone, or the like, or ceramic, metal, or the like may be used as the plastic. Further, as a manufacturing method, the material is molded by molding, etching, laser processing, or the like,
The glass plate may be processed using the photolithography technique, or the photo-curable resin fused or adhered to the glass plate or the metal plate may be processed using the photolithography technique and molded.

The number of nozzle hole rows is “2 rows × 1”.
The number is not limited to “2 rows × 2”, and any number may be provided as necessary.

[0059]

As described above, the present invention has the following excellent effects.

By supplying water-soluble ink and non-water-soluble ink to the recording head to perform recording on one recording head substrate, color mixing of two colors of ink can be prevented, and one integrated small recording. Two colors of ink can be used in the head, and it is not necessary to provide a head unit and a pump unit for each color.

Since the color mixture can be prevented by alternately arranging the nozzle hole rows for water-soluble ink and the nozzle hole rows for non-water-soluble ink, when the inks of more than two colors are used, the distance between the heads is reduced. Can be narrowed.

From the above, it is possible to miniaturize the multicolor recording head, and to provide a smaller multicolor ink jet printer. This has the effect of saving space when using the inkjet printer of the present invention.

Further, the number of parts of the recording head can be reduced, the yield can be improved, the manufacturing process of the ink jet printer can be simplified, and a low cost ink jet printer can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view of a recording head showing an embodiment of the present invention.

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

FIG. 3 is a perspective view of a recording head showing an embodiment of the present invention.

FIG. 4 is a perspective view of a recording head showing an embodiment of the present invention.

FIG. 5 is a top view of the recording head during the ejection of ink droplets showing an embodiment of the present invention.

FIG. 6 is a perspective view of a recording head showing an embodiment of the present invention.

FIG. 7 is a top view of the recording head during the ejection of ink droplets showing an embodiment of the present invention.

FIG. 8 is a perspective view of a recording head showing an embodiment of the present invention.

FIG. 9 is a top view of the recording head during the ejection of ink droplets showing an embodiment of the present invention.

FIG. 10 is a cross-sectional view of a recording head and a cap during cleaning according to an embodiment of the present invention.

FIG. 11 is a perspective view of a recording head showing an embodiment of the present invention.

FIG. 12 is a perspective view of a recording head and a suction device showing an example of a conventional technique.

FIG. 13 is a perspective view of a recording head and a suction device showing an example of a conventional technique.

FIG. 14 is a side view of a recording head and a cleaning device showing an example of a conventional technique.

[Explanation of symbols]

 10 flow path forming substrate A 11 flow path sealing substrate a 12 flow path sealing substrate b 13 piezoelectric element 14 nozzle hole 15 cap 30 flow path forming substrate C 31 flow path forming substrate D 32 flow path sealing substrate e 33 flow path Sealing substrate f 34 Channel sealing substrate g 35 Channel sealing substrate h 36 Piezoelectric element 37 Nozzle hole 38 Nozzle hole 39 Cap 300 Spacer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadaho Murata 3-3-5 Yamato, Suwa City, Nagano Seiko Epson Corporation

Claims (3)

[Claims] 1. An ink jet printer for ejecting ink from a nozzle hole of a recording head to form flying droplets and recording a dot image on a recording medium, wherein at least two nozzle hole rows of the recording head are arranged. An inkjet printer characterized in that a water-soluble ink and a water-insoluble ink are alternately supplied to the nozzle hole array. 2. The ink jet printer according to claim 1, wherein inks of different colors are supplied to the at least two or more nozzle hole arrays. 3. The ink jet printer according to claim 2, wherein the recording head has three rows of nozzle holes capable of ejecting at least three colors of ink, and the three colors are yellow, magenta, and cyan.