JPH08142336A - Ink jet recording apparatus and method and reliability recovery method - Google Patents

Abstract

PURPOSE: To eliminate clogging and to facilitate the washing of an energy acting part by constituting an energy acting substrate having the energy acting part formed thereon and a common ink supply part for supplying ink in a separable manner. CONSTITUTION: An opening 11 is provided to a first substrate 8 and ink is guided to the ink supply liquid chamber 12 formed by laminating the first substrate 8, a second substrate 9 and a spacer 10 through the opening 11. The spacer 10 is not provided to the region near to an energy acting substrate 1 but provided to the outer peripheral part of the first substrate 8 in order to form a gap (cavity region) becoming the ink supply liquid chamber 12. By making the energy acting substrate 1 and an ink supply part 7 separable, even if a phenomenon losing reliability such as the adhesion of waste refuse or the drying of ink is generated in the energy acting substrate 1, the substrate 1 can be easily separated to be washed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called ink jet recording apparatus for ejecting and recording ink, a recording method therefor, and a reliability recovery method, and more particularly, it is simple in a large-scale large array ink jet system. The present invention relates to a recording apparatus, a recording method, and a reliability recovery method having a novel structure and a highly reliable novel principle and structure.

[0002]

2. Description of the Related Art The non-impact recording method has recently attracted interest in that noise generation during recording is negligibly small. Among them, the so-called inkjet recording method, which enables high-speed recording and can perform recording on so-called plain paper without requiring a special fixing process, is an extremely powerful recording method, and various recording methods have been used so far. Some methods have been proposed and improved, and some have been commercialized, while others have been making efforts to put them into practical use.

Such an ink jet recording method is one in which droplets of a recording liquid, which is so-called ink, are ejected and adhered to a recording member to perform recording. It is proposed in Japanese Examined Patent Publication No. 56-9429. In this publication, the ink in the liquid chamber is heated to generate bubbles to cause a pressure increase in the ink, and the ink is ejected from a fine capillary nozzle for recording.

Since then, many inventions have been made utilizing this principle. For example, in the invention described in Japanese Patent Publication No. 3-5992, a substrate on which a heating element that generates thermal energy for ejecting a liquid is formed, and the heating element of the substrate is bonded to the substrate. A plurality of inkjet head blocks having an orifice for discharging the liquid and a liquid guide portion forming a liquid chamber for supplying the liquid to the heating element portion are common to each of the plurality of inkjet head blocks. It is provided on the upper and lower surface of the plate. When such a configuration is adopted, by arranging the inkjet head blocks so as to cover the entire recording paper width, a so-called full line type multi-nozzle head is realized, and several 1 / minute is achieved.
A high speed printer such as 0 sheets is realized.

[0005]

However, in the conventional full-line type ink jet recording apparatus, the number of nozzles becomes very large. For example, when considering an example of covering the short side direction of A4 size paper, 400 dpi When the array density is used, the number of nozzles is 3000 or more, and a problem in reliability, such as measures against nozzle clogging, becomes a problem. Further, as another problem, there is a problem in image quality that white streaks (white spots) and black streaks are generated due to insufficient accuracy of joints of the inkjet head blocks.

The problem of such white stripes and black stripes is that a full-line type multi-nozzle head is formed by a so-called large-scale large array method as disclosed in Japanese Patent Laid-Open No. 3-58848. You can solve it. However, this method still
The problem of nozzle clogging cannot be solved.

The present invention has been made in view of the above circumstances. First, in a large-scale large array type ink jet system, firstly, an ink jet recording head having a novel constitution which has not been hitherto proposed is proposed. To propose an ink supply unit with a simple structure of such a novel inkjet recording head, and third, to clarify the structure of the connection unit of the ink supply unit with the energy acting substrate. Fourth, to increase the ink flying efficiency of such a novel inkjet recording head,
First, to prevent damage to the barrier in the vicinity of the energy acting portion of the ink jet recording head or the ink supply portion with improved ink flying efficiency. Sixth, from the ink supply portion of such a novel ink jet recording head. Preventing the supplied ink from moving to unnecessary areas, 7th, ensuring the prevention of the movement, 8th, recording using such a novel inkjet recording head The purpose of the present invention is to propose a method for carrying out the method, ninthly, to propose a reliability recovery method in such a novel recording method, and tenthly, to propose another reliability recovery method. Is.

[0008]

In order to solve the above problems, the present invention has the following constitution. First
In the ink jet recording head, the energy acting substrate is formed with a plurality of energy acting portions and a common ink supply portion that presses against the substrate to supply ink to the energy acting portion. The ink supply unit is separable from the ink supply unit. Secondly, in the first ink jet recording head, the ink supply unit is formed by stacking two substrates with a gap therebetween, and the gap serves as an ink supply liquid chamber. Third
In the second ink jet recording head, the two substrates were laminated by shifting the positions of the end portions of the two substrates so that only one of the two substrates was in contact with the energy acting substrate. Fourthly, in the inkjet recording head of 1 or 2 or 3, a barrier is provided between the adjacent energy action portions of the energy action. Fifthly, in the fourth inkjet recording head, the barrier is
The height is set so that it does not come into contact with the one of the two substrates of the ink supply unit that does not come into contact with the energy acting substrate. Sixthly, in the ink jet recording head described in the paragraph 2 or 3 or 5, water-repellent or oil-repellent treatment is applied to a region of the energy-applying substrate which is in contact with one of the two substrates of the ink supply unit. . Seventh
In the ink jet recording head according to the second or third or fifth or sixth aspect, in the vicinity of a region of the energy acting substrate which is in contact with one of the two substrates of the ink supply unit, the substrate is A barrier for preventing outflow of unnecessary ink is provided in the area opposite to the energy acting portion by sandwiching. Eighth, in the ink jet recording method, the ink supply means is pressed against the energy application substrate on which the energy application part is formed, the ink is supplied from the ink supply means to the energy application part, and the energy application part responds to the image information. Then, a signal is input to drive the energy acting portion to cause a part of the ink in the vicinity to fly and adhere to the recording medium for recording. Ninth, it comprises an energy acting substrate having a plurality of energy acting parts and a common ink supply part which is pressed against the substrate to supply ink to the energy acting part. In a method for recovering the reliability of an inkjet recording head that is separable from the supply unit,
The ink supply unit was moved from the energy application substrate, and the cleaning liquid was applied to the energy application unit. Tenth, it comprises an energy acting substrate having a plurality of energy acting portions and a common ink supply portion pressed against the substrate to supply ink to the energy acting portions, the energy acting substrate and the ink. In the method of recovering the reliability of an ink jet recording head that is separable from the supply unit, the ink supply unit is moved from the energy application substrate and the energy application unit is immersed in a cleaning liquid.

[0009]

The present invention provides an ink jet recording head in which an energy acting portion and an ink supplying portion can be separated without using a nozzle, which is free from clogging and in which the energy acting portion can be easily washed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of an ink jet recording head according to an embodiment of the present invention.
Reference numeral 1 denotes a heating element substrate, and the heating element substrate 1 is composed of a first electrode (control electrode) 2, a second electrode (earth electrode) 3, a heating element 4, bonding pads 5, 6 and the like. Further, 7 is an ink supply unit, which is composed of a first substrate 8, a second substrate 9, a spacer 10 and the like.
FIG. 3 is a perspective view showing a state in which the ink supply unit 7 and the ink supply unit 7 are separated, but when actually ejecting ink, as shown in FIG.
The heating element substrate 1 is used while being pressed against the first substrate 8 of the ink supply unit 7.

FIG. 2 is a sectional view showing a state of use of the ink jet recording head shown in FIG. 1. As shown in FIG.
The substrate 8 is provided with an opening 11, and the ink passes through the opening 11 to form an ink supply liquid chamber 12 formed by stacking a first substrate 8, a second substrate 9 and a spacer 10.
Be led to. The spacer 10 is provided in the outer peripheral portion of the first substrate 8 rather than in the region close to the heating element substrate 1 in order to form a gap (hollow region) which becomes the ink supply liquid chamber 12.

Next, the heating element substrate 1 and the heating element 4 will be described. FIG. 3 is an enlarged view of a section AA in FIG. 1 and is a sectional view near the heating element. In FIG. 3, 31 is a substrate (Si), 32 is a heat storage layer (SiO ₂ ), 33 is a heating element (HfB ₂ ), 34 is an electrode (Al), 35 is a protective layer (SiO ₂ ), and 36 is an electrode protective layer. (Resin), 37 is a cavitation-resistant protective layer (Ta), 38 is a heat generating portion, 39
Is an electrode part, and each heating element can be driven independently. The second electrode 3 is composed of a plurality of heating elements (first electrodes).
However, it is also possible to use one common second electrode. For example, 3072 such heating element rows are provided with an array density of 400 dpi, and have a printing width that can cover the lateral direction of A4 size paper.

The heating element substrate 1 having such a large size
Is manufactured, for example, by making full use of a thin film forming technique such as sputtering and a pattern forming technique such as photolithography etching on an alumina substrate provided with a grace layer used when manufacturing a thermal head or the like. In recent years, S
Since an i-wafer having a diameter of 8 inches or more can be manufactured, a Si wafer can also be used. Therefore, here, a method of manufacturing such a heating element substrate using a Si wafer will be briefly described.

First, the Si wafer 31 is, for example, 800 to 1000 while flowing O ₂ and H ₂ O gases in a diffusion furnace.
Exposed to a high temperature of ℃, thermal oxide film SiO ₂ on the surface 1-2
Grow μm. This SiO ₂ acts as a heat storage layer 32, and prevents heat generated by a heat generating element described later from escaping to the substrate, so that heat can be efficiently transmitted in the direction of the ink.

Next, a method of forming the heating element 33, the electrodes 34, etc. will be described. FIG. 3 is a detailed cross-sectional view of the vicinity of the heating element part, in which the heating element layer 33 is formed on the heat storage layer (SiO ₂ ) 32.
However, useful materials for the heating element 33 include tantalum-SiO ₃ mixture, tantalum nitride, nichrome, silver-palladium alloy, silicon semiconductor, or hafnium, lanthanum, zirconium, titanium, tantalum. , Tungsten, molybdenum, niobium,
Examples thereof include borides of metals such as chromium and vanadium. Among the metal borides, hafnium boride has the most excellent properties, followed by zirconium boride, lanthanum boride, tantalum boride, vanadium boride, and niobium boride.

The heating element 33 can be formed by using a method such as electron beam evaporation or sputtering using the above-mentioned materials. The film thickness of the heating element is determined according to the area and material, the shape and size of the heat-acting portion, and the actual power consumption so that the heat generation amount per unit time is as desired. However, in the normal case, 0.001-
The thickness is 5 μm, preferably 0.01 to 1 μm. In the embodiment of the present invention, an example was shown in which HfB ₂ was sputtered at 2000Å.

As the material forming the electrode 34, many of the commonly used electrode materials are effectively used.
Specifically, for example, Al, Ag, Au, Pt, Cu
Etc., and these are used to provide a predetermined size, shape, and thickness at a predetermined position by a technique such as vapor deposition. In the present invention, Al is formed to a thickness of 1.4 μm by sputtering.

The characteristic required of the protective layer 35 is that the heating element is protected from the recording liquid without hindering effective transfer of the heat generated by the heating element to the recording liquid. The useful material for the protective layer 35 includes:
Examples thereof include silicon oxide, silicon nitride, magnesium oxide, aluminum oxide, tantalum oxide, zirconium oxide, and the like, which can be formed by a method such as electron beam evaporation or sputtering. Also,
Ceramic materials such as silicon carbide and aluminum oxide (alumina) are also preferably used materials. The thickness of the protective layer is usually 0.01 to 10 μm, preferably 0.1 to 5 μm.
m, most preferably 0.1 to 3 μm. In the present invention, SiO ₂ is formed to a thickness of 1.2 μm by sputtering. Further, in the present invention, in order to protect the heating element region from the cavitation destruction due to the generation of bubbles, Ta was formed as the cavitation resistant protective layer 37 by sputtering by 4000 Å. Further, a resin layer having a thickness of 2 μm is formed as the electrode protection layer 36.

Next, the manner in which the ink jets by the ink jet recording head of the present invention is ejected, as shown in FIGS.
This will be described with reference to (h). In the figure, 4 is a heating element, 13 is ink, 14 is a bubble, 15 is a grown ink column, and 16 is flying ink. FIG. 4A shows a steady state,
The ink 13 supplied from the ink supply unit is in the state of forming a meniscus held by surface tension near the heating element 4. Next, a signal pulse is input to the heating element 4 connected to the image signal generating means (not shown) according to the image information, and the surface of the heating element is heated.
As shown in (b), micro bubbles 14 are generated. Further, by continuing to energize the heating element 4, the minute bubbles 1
4 becomes one united bubble 14 (FIG. 4 (c)). Further, when the energization is continued, the bubble 14 becomes the maximum size as shown in FIG. 4D, and the surface of the ink meniscus rises accordingly, and the grown ink column 1
5 (FIG. 4 (e)). At this point, the heating element 4 is de-energized, and the bubbles 14 are deprived of heat by the surrounding ink and the heating element substrate, and begin to contract. As a result, the ink column 15 has a constriction at its root portion, and the ink column 15 is eventually cut off at that portion to become flying ink 16 (FIG. 4 (f)). After that, the ink meniscus is once retracted (dented, the state shown in FIG. 4G), and then becomes the original steady state (FIG. 4H).

Here, the energization time of the signal pulse to the heating element 4 of the ink jet recording head of the present invention is several μs to 1 μs.
0 μs is desirable, and at most 30 μs is set.
This is because, in part, the heating element is instantly heated to 300 to 400 ° C. to obtain a so-called film boiling state, so that stable bubble generation-growth-contraction-disappearance is achieved and stable ink flight is performed. This is because the boiling and boiling at 100 [deg.] C. usually does not allow stable generation and disappearance of bubbles.
Another reason is that if the heating element 4 is energized for too long, the heating element 4 will be damaged.

Next, another feature of the present invention will be described. In principle, the ink flying of the present invention is performed as described above, but the present invention does not have a nozzle such as a so-called conventional ink jet, and the pressure due to the bubbles that are the driving force of the ink flying is dispersed in the surroundings. It has the property that the efficiency of flight is rather low. Further, there is also a property that the pressures of bubbles caused by the adjacent heating elements influence each other (crosstalk), and the ink flying becomes unstable. Therefore, an example in which a barrier for preventing pressure dispersion and a barrier for preventing crosstalk is provided in order to improve such properties will be described below.

FIG. 5 shows a heating element substrate 1 as shown in FIG.
6A to 6 are perspective views in the case where the barrier 40 is formed in FIG.
6C is a diagram for explaining the step of forming the barrier 40, FIG. 6A is a sectional view of the heating element substrate, FIG. 6B is a diagram showing an exposed state, and FIG. In the figure, 41 is a substrate (Si or alumina), and 42 is a state after development.
Is a heating element, 43 is a thin film such as a protective film, 44 is a photoresist, 44a is a barrier formed after development by exposure, 4
Reference numeral 5 is a photomask, and 46 is a flow path formed after exposure and development.

FIG. 6A shows a heating element substrate (as seen from the direction of the arrow B in FIG. 1), and in the next step shown in FIG. 6B, it is shown in FIG. 6A. For example, a photoresist 44 of 1000 to 2000 cp is coated on the heating element substrate by spin coating, dip coating, or roller coating to have a thickness of about several tens of μm to 30 μm. This thickness will ultimately be the height of the barrier. To obtain a resist layer having a thickness of 30 μm or more, a dry film type photoresist may be used instead of a liquid photoresist. If a dry film type photoresist is used, the thickness is 100 μm.
It is possible to form even a resist layer. In that case, a resist layer is formed by applying heat and pressure to laminate on the substrate.

Subsequently, as shown in FIG. 6B, a photomask 45 having a predetermined pattern is superposed on the photoresist 44 provided on the surface of the heating element substrate, and then the photomask 45 is removed from above. Expose. At this time, the heating element 4
It is necessary to align the installation position of No. 2 and the pattern. FIG. 6C is a diagram for explaining a step after the unexposed portion of the exposed photoresist 44 is dissolved and removed by an alkali developing solution such as an aqueous solution of sodium carbonate, and the photo remaining on the substrate 41. In order to improve ink resistance of the exposed portion 44a of the resist 44, heat curing treatment (for example, heating at 150 to 250 ° C. for 30 minutes to 60 hours) or ultraviolet irradiation (for example, 50 to 200 mW / cm ^2).
Or more (ultraviolet intensity) to sufficiently advance the polymerization and curing reaction. It is also effective to use both the heat curing and the ultraviolet curing.

As described above, in the case where the barrier is formed, compared with the case where the barrier is not formed (see FIGS. 1 and 2).
There is an advantage that the meniscus formation of the ink supplied from the ink supply unit 7 in the vicinity of the heating element can be performed stably and with good reproducibility, and thus an advantage that the ink flying is stable and performed with good reproducibility. Furthermore, since the pressure of bubbles generated by this barrier contributes efficiently to ink flying without being dispersed, the ink flying speed is fast, the flying ink droplets (or ink columns) are stable, and the recording medium (for example, Can be accurately driven to the desired position on the
There are advantages that the dot position accuracy is improved and high image quality is obtained.

Another advantage is that the presence of this barrier is a phenomenon often seen in ordinary ink jets when adjacent heating elements are driven at about the same time.
This means that there is almost no phenomenon called so-called crosstalk that interferes with each other. This is barrier 4
This is because 0 serves to prevent the pressure of the generated bubbles from affecting each other. By eliminating crosstalk in this way, adjacent jets (ink columns, ink droplets) do not affect each other, so that the flight directions of each jet are stable, the dot position accuracy is improved, and high image quality is obtained. is there. Further, in the conventional inkjet, when there is crosstalk, a method of ejecting one of the adjacent jets without ejecting the adjacent jets at the same time, and then the other effect is suppressed However, in the present invention, since it is possible to prevent the crosstalk by providing a barrier, it is not necessary to fly the ink at a time lag and the adjacent jets Since it is possible to fly at almost the same time, there is an advantage that the printing speed does not decrease.

Next, another feature of the present invention will be described. In the present invention, as described above, the energy acting substrate (heating element substrate) 1 and the ink supply unit 7 are separable. This cannot solve the problem of clogging of nozzles when a full line type multi-nozzle head is constructed in an inkjet system of the conventional type having nozzles as disclosed in Japanese Patent Laid-Open No. 3-58848. In view of this, the so-called conventional nozzle is eliminated to solve the problem of clogging, or even if a problem equivalent to conventional clogging occurs, it can be immediately solved. It has such a configuration. This will be specifically described with reference to the drawings.

FIG. 7A shows an example in which the ink jet recording head of the present invention is mounted on the supporting member 20. Here, 21 is an ink supply unit holding unit, and 22 is an energy acting substrate holding unit. Reference numeral 23 denotes a heating element substrate (energy acting substrate) chuck portion, which is connected to the energy acting substrate holding portion 22 by a shaft 24 and is rotatable there. Incidentally, 25 is a cleaning liquid recovery container. FIG. 7A shows a positional relationship between the heating element substrate (energy acting substrate) 1 and the ink supply unit 7 in a normal printing state. Usually, when used in such a state, foreign matter such as dust floating in the air, paper dust, etc. adhere to the vicinity of the heating element 4, or the ink dries and solidifies. Sometimes fall into. However, according to the present invention, even in such a state, as shown in FIG.
As shown in (b), the heating element substrate 1 is connected to the ink supply unit 7
The cleaning liquid is sprayed from the cleaning liquid spray nozzle 26 for cleaning to remove foreign matter and dry ink as described above, and the vicinity of the heating element 4 can be kept clean, for example. It is possible to perform stable ink flight. The cleaning method will be briefly described.

First, FIG. 7A shows a state at the time of printing. When an abnormality occurs in ink flight due to adhesion of foreign matter, ink drying, or the like (this can be detected by observing the printing state), as shown in FIG. The part 23 is rotated around the shaft 24 and placed inside the cleaning liquid recovery container 25. Next, the cleaning liquid jet nozzle 26 and the air jet nozzle 27 are moved to the vicinity of the heating element 4 by a moving device (not shown), and the cleaning liquid is jetted to remove foreign matter.
After that, the cleaning liquid is wiped off by wiping clean air that has been filtered through the filter, and the vicinity of the heating element 4 of the heating element substrate 1 is cleaned. Then, the cleaning liquid injection nozzle 26
Then, the air jet nozzle 27 is retracted, the heating element substrate 1 again comes into contact with the ink supply portion 7 by the rotational movement of the shaft 24, and is returned to the original state as shown in FIG. It is ready for copying.

The cleaning liquid used here is composed of one to a plurality of components, but at least one composition is the same as the composition constituting the ink. Specifically, for example, when the ink having a composition such as glycerin: 30 wt%, ethyl alcohol: 4.8 wt%, water: 63 wt%, direct black 154 (dye): 2.2 wt% is used, The cleaning liquid is water: 96 wt%, ethyl alcohol: 3 wt%, surfactant (BT12): 1
A composition such as wt% may be used. Needless to say, without being limited to this composition, for example,
Water: A cleaning liquid of 100 wt% may be used. If the cleaning liquid contains a large amount of components other than water (for example,
(80 parts of water and 20 parts other than that), two cleaning liquid injection nozzles are provided, the cleaning liquid is first injected, and then,
It is advisable to spray water to flush out the cleaning liquid.
Further, the above example shows an example in which water is used as the ink, but in the case of solvent-based ink, it is preferable that the cleaning liquid is also solvent-based. At that time, a device for sealing and recovery is required so that the generated solvent vapor does not drift around. As the cleaning air, air filtered with a filter of about 1 to 5 μm is used. Further, the injection pressure of the cleaning liquid and the air is set to 1 to 3 kg / cm ² .

FIG. 8 is a diagram showing another example of the method for cleaning the heating element portion 4. In this case, instead of wiping the cleaning solution, the heating element substrate 1 is jabbed in the cleaning solution in the cleaning container 28. The attached example is shown. Also in this case, after the cleaning, the heating element substrate 1 is lifted from the cleaning container 28 by rotational movement, and before contacting with the ink supply unit 7, clean air is wiped by an air jet nozzle (not shown) and the cleaning liquid is wiped off. Is done. Such cleaning with a jab has the effect that the cleaning liquid is surely spread over the portion to be cleaned (dirt). In the cleaning container 28, the heating element substrate 1
If the ultrasonic wave is swung or an ultrasonic oscillator is attached to the cleaning container 28 and ultrasonic cleaning is performed, more reliable cleaning is performed. Further, when the cleaning with the cleaning liquid jet nozzle shown in FIG. 7B is combined with this jabing cleaning, the most reliable cleaning can be performed.

Next, another feature of the present invention will be described. As shown in FIGS. 1 and 2, the ink supply unit of the present invention is basically configured such that the ink is carried through the narrow gap by the capillary phenomenon and a meniscus is formed in the vicinity of the heating element. A specific method of making the same will be described below. FIG. 9 is an exploded perspective view of the ink supply unit 7 shown in FIG. 1, and the first substrate 8 made of a material such as alumina ceramics or Pyrex glass is formed by a technique such as ultrasonic processing, laser processing, or etching. An opening 11 for introducing ink is formed therein. Next, the spacer 10 is formed in order to form a gap (ink supply liquid chamber 12) for moving the ink by the capillary phenomenon. This is achieved, for example, by using the photolithography technique used to form the barrier on the heating element substrate described above. The thickness of the spacer region (= the gap for ink movement due to the capillary phenomenon) is, for example, 50 to 20.
It is set to 0 μm and can be obtained by using a dry film type photosensitive resin. Next, by stacking a material such as Pyrex glass as the second substrate 9, the ink supply unit is completed. Here, the spacer 1
The 0 and the second substrate 9 can be joined by utilizing the tackiness of the semi-cured state before the photosensitive resin is completely cured. In addition, the joining becomes stronger by heating and pressurizing as needed. Alternatively, the second substrate 9
A photosensitive resin layer may be provided as a bonding layer on the side, and bonding may be performed by the bonding force between the photosensitive resins. It is also a good method to use an adhesive.

When formed by the above method, the thickness of the first substrate 8 is preferably larger than 0.5 mm in consideration of the mechanical strength of the entire ink supply section 7. Further, the thickness of the second substrate 9 needs to take into consideration the size of the meniscus region when the meniscus of the ink is formed by contacting with the heating element substrate.
A thickness of 1 mm is desirable. If the thickness is smaller than this, the meniscus region is easily destroyed in manufacturing or handling, and if the thickness is thick, the formed meniscus region becomes too large (wide), and the meniscus is not optimal for flying ink.

Next, another feature of the present invention will be described. The ink supply unit of the present invention is formed by the method as described above, but the ink supply unit shown in FIG. 1, FIG. 2, FIG. 4, FIG.
As is apparent from FIG. 9, the first substrate 8 and the second substrate 9
The end portions of the sheets are stacked with the positions thereof shifted. This is shown in Figure 4.
This is because the meniscus of the supplied ink is preferably formed and the heating element region is covered with an appropriate amount of ink, as is apparent from FIG. The preferable deviation amount Δ (see FIG. 10) depends on the printing density, the size of the heating element, etc., but the printing density is 400 μm to 800 dpi, and the size of the heating element is 30 μm × 160 μm. (400
dpi) ~ 16μm x 80μm (800dpi)
In that case, the thickness is about 120 μm to 30 μm. or,
As described above, in the case where the barriers 40 are formed on both sides of the heating element 4, the deviation amount Δ needs to take the height of the barriers 40 into consideration. That is, as shown in FIG. 11, it is necessary to make a gap G so that the barrier 40 and the second substrate 9 are not in contact with each other while the ink supply unit 7 is in contact with the heating element substrate 1. is there. The specific value of the gap G is at least about 20 μm, or more, so that when the ink supply unit 7 and the heating element substrate are brought into contact with each other, the second substrate 9 and the barrier 4 are provided.
The situation where 0s collide and are damaged is avoided.

Next, another feature of the present invention will be described. In the present invention, as described above, the ink supply unit 9 and the heating element substrate 1 can be separated, and they are separated or contacted (connected) when necessary. At that time, the ink in the ink supply unit may adhere to an undesired region of the heating element substrate (for example, an electrical connection unit such as a bonding pad) and cause an unexpected failure. Therefore,
According to the present invention, even if extra ink in the ink supply unit is attached to the original position of the heating element substrate 1, that is, a portion other than the vicinity of the heating element 4, the ink still flows to other areas. In order to prevent the ink from flowing into or penetrating into the heating element substrate in the vicinity S (see FIG. 12) of the area where the first substrate 8 of the ink supply unit 7 is in contact with the heating element substrate 1, Water or oil repellent treatment is applied. Specific water and oil repellency treatments are carried out, for example, by applying a toluene solution of silicone resin, an aqueous solution of gum arabic-phosphoric acid, a Teflon dispersion, or the like by spray coating.

As another countermeasure against the similar problem,
It can also be obtained by forming a barrier so that unnecessary ink does not flow to other areas. FIG. 13 shows an example thereof, and a barrier 50 is formed in place of the above-mentioned water repellent and oil repellent treatment so that unnecessary ink does not flow. Such a barrier 50 can be formed by the same method as the barrier 40 formed in the vicinity of the heating element 4 for preventing pressure dispersion, that is, the photolithography technique. Particularly, if it is formed at the same time as the barrier for preventing the pressure dispersion, it is not necessary to separately manufacture the barrier for preventing the ink flow in a separate process, and the cost can be reduced. Further, by combining both the water-repellent and oil-repellent treatments and the formation of the barrier, it is possible to surely prevent the unnecessary ink from flowing out.

Concrete Example 1 Heat generating substrate: 80 μm × 400 μm (resistance value 110
Ω) -sized heating element formed on an alumina substrate in 1 row at an array density of 200 dpi-Barriers on both sides of the heating element: None-Water repellent treatment near the heating element substrate and ink supply section: None- Ink supply part: First substrate ... Pyrex glass with a thickness of 1.6 mm Second substrate ... Pyrex glass with a thickness of 0.2 mm Gap between the first and second substrates ... 0.2 mm Edge of the second substrate Ink amount: glycerin; 45 wt%, ethyl alcohol; 4.8 wt%, water; 48 wt%, direct black 154 (dye); 2.2 wt% ・ Heating element drive condition: drive voltage V ₀ = 28 V, drive pulse width Pw = 7 μs, drive frequency F ₀ = 1 kHz

When the ink was ejected under the above conditions, the ink ejection speed was Vj = 8.5 m / s, and Φ was obtained by using Mitsubishi Paper Matt Coated Paper NM as the recording paper.
A pixel having a size of 178.4 μm could be obtained. Next, when the drive frequency was increased from F ₀ = 1 kHz to F ₀ = 3 kHz, ink flight became unstable, and the dot position accuracy on the paper surface deteriorated. Next, when two adjacent heating elements were driven at the same time, it was observed that the flying inks repel each other and the flying direction deteriorates.

Next, when this apparatus was left for 10 days, the ink in the vicinity of the heating element part was partially dried and solidified,
Further, it was observed that dust was attached. Therefore, when the heating element substrate and the ink supply section are separated and pure water is applied to the heating element section, the dried and solidified ink and dust can be easily washed away to restore the original clean state. It was
After that, when the heating element substrate and the ink supply section were brought into contact with each other and ink was ejected under the above conditions, almost the same ink ejection as before could be obtained. When the ink supply section was re-contacted, it was observed that the ink was slightly protruding near the contact section.

Specific Example 2 Heating substrate: 80 μm × 400 μm (resistance value 110
Ω) -sized heating element formed on an alumina substrate in 1 row at an array density of 200 dpi-Barriers on both sides of the heating element: Yes, barrier height: 80 μm-In the vicinity of the heating element substrate and the ink supply section Water repellent treatment: None ・ Ink supply part: first substrate ... Pyrex glass with a thickness of 1.6 mm Second substrate ... Pyrex glass with a thickness of 0.2 mm Gap between first and second substrates ... 0.2 mm 2) Substrate edge shift amount: 0.15 mm-Ink: glycerin; 45 wt%, ethyl alcohol; 4.8 wt%, water; 48 wt%, direct black 154 (dye); 2.2 wt% -heating element driving conditions : Drive voltage V ₀ = 28 V, drive pulse width Pw = 7 μs, drive frequency F ₀ = 1 kHz

When the ink was ejected under the above conditions, the ink ejection velocity was Vj = 10.8 m / s,
A matte coated paper NM manufactured by Mitsubishi Paper Mills was used as a recording paper, and a pixel with a size of φ182.5 μm could be obtained.
Next, the driving frequency was increased from F ₀ = 1 kHz to F ₀ = 3 kHz, but the ink flying was stable and the ink flying state hardly changed. Next, two adjacent heating elements were driven simultaneously, but stable flight was obtained with both flying inks.

Concrete Example 3 Heating element substrate: 30 μm × 160 μm (resistance value 105
Ω) -sized heating elements formed on a Si wafer in an array density of 400 dpi in 512 rows.-Barriers on both sides of the heating element: Yes, barrier height; 30 μm-In the vicinity of the heating element substrate and ink supply part Water repellent treatment: None-Ink supply part: First substrate ... Pyrex glass with a thickness of 1.6 mm Second substrate ... Pyrex glass with a thickness of 0.1 mm Gap between first and second substrates ... 0.1 mm Amount of deviation of the edge of the substrate of No. 2 ... 0.06 mm-Ink: glycerin; 45 wt%, ethyl alcohol; 4.8 wt%, water; 48 wt%, direct black 154 (dye); 2.2 wt% -heating element driving conditions : Drive voltage V ₀ = 26V, drive pulse width Pw = 5 μs, drive frequency F ₀ = 4 kHz

When the ink was ejected under the above conditions, the ink ejection speed was Vj = 11.6 m / s,
Pixels with a size of φ100.3 μm could be obtained by using matte coated paper NM manufactured by Mitsubishi Paper Mills as recording paper.
Next, two adjacent heating elements were driven simultaneously, but stable flight was obtained with both flying inks. When the ink supply unit and the heating element substrate were attached and detached many times, it was observed that the ink was widely bleeding and smeared in the vicinity of the contact portion of the heating element substrate.

Concrete Example 4 Heating element substrate: 30 μm × 160 μm (resistance value 105
Ω) -sized heating elements formed on a Si wafer in an array density of 400 dpi in 512 rows.-Barriers on both sides of the heating element: Yes, barrier height; 30 μm-In the vicinity of the heating element substrate and ink supply part Water repellent treatment: Yes (Teflon resin coating) -Ink supply part: First substrate ... Pyrex glass with a thickness of 1.6 mm Second substrate ... Pyrex glass with a thickness of 0.1 mm Gap between the first and second substrates … 0.1 mm Displacement of edge of second substrate… 0.06 mm ・ Ink: glycerin; 45 wt%, ethyl alcohol; 4.8 wt%, water; 48 wt%, direct black 154 (dye); 2.2 wt% Heating element driving condition: driving voltage V ₀ = 26 V, driving pulse width Pw = 5 μs, driving frequency F ₀ = 4 kHz

When the ink is ejected under the above conditions, the ink ejection velocity is Vj = 11.5 m / s,
A matte coated paper NM manufactured by Mitsubishi Paper Mills was used as a recording paper, and pixels with a size of φ100.6 μm could be obtained.
When the ink supply unit and the heating element substrate were attached and detached many times, it was observed that the ink was attached in the vicinity of the contact portion of the heating element substrate. It didn't spread any further.

Specific Example 5 Heating element substrate: 30 μm × 160 μm (resistance value 105
Ω) -sized heating elements formed on a Si wafer in an array density of 400 dpi in 512 rows.-Barriers on both sides of the heating element: Yes, barrier height; 30 μm-In the vicinity of the heating element substrate and ink supply part Water repellent treatment: Yes (Teflon resin coating) A barrier was formed so as to surround the ink supply section in the region where the heating element substrate and the ink supply section were in contact. This barrier is formed by photolithography at the same time when the heating element and the barriers on both sides are formed. Ink supply unit: First substrate ... Pyrex glass with a thickness of 1.6 mm Second substrate ... Pyrex glass with a thickness of 0.1 mm Gap between first and second substrates ... 0.1 mm Edge of second substrate Ink: Glycerin; 45 wt%, Ethyl alcohol; 4.8 wt%, Water; 48 wt%, Direct Black 154 (dye); 2.2 wt% ・ Heating element drive condition: Drive voltage V ₀ = 26 V, drive pulse width Pw = 5 μs, drive frequency F ₀ = 4 kHz

When the ink was ejected under the above conditions, the ink ejection speed was Vj = 11.2 m / s,
Pixels with a size of φ100.1 μm could be obtained by using matte coated paper NM manufactured by Mitsubishi Paper Mills as a recording paper.
When the ink supply unit and the heating element substrate were attached and detached many times, it was observed that ink was attached near the contact portion of the heating element substrate, but due to the effect of the water repellent treatment, There was no way the ink could spread any further, blocked by the barrier.

Concrete Example 6-Heating element substrate: A heating element having a size of 18 μm × 76 μm (resistance value 96 Ω) formed on a Si wafer in an array density of 800 dpi in a row, and 256 barriers on both sides of the heating element: Yes, barrier height: 10 μm ・ Water repellent treatment in the vicinity of the heating element substrate and the ink supply section: Yes (Teflon resin coating) A barrier is formed so as to surround the ink supply section in the contact area between the heating element substrate and the ink supply section did.
This barrier is the above heating element, when forming the barrier on both sides,
At the same time, it is formed by photolithography. Ink supply unit: First substrate ... Pyrex glass with a thickness of 1 mm Second substrate ... Pyrex glass with a thickness of 0.05 mm Gap between first and second substrates ... 0.05 mm At the end of the second substrate Displacement amount ... 0.03 mm-Ink: glycerin; 45 wt%, ethyl alcohol; 4.8 wt%, water; 48 wt%, direct black 154 (dye); 2.2 wt% -Heating element drive condition: drive voltage V ₀ = 18 V , Drive pulse width Pw = 3 μs, drive frequency F ₀ = 5 kHz to 30 kHz
z

When ink is ejected under the above conditions, the ink ejection speed is Vj = 9.1 m / s-10.5.
m / s, and stable ink flight was obtained. Also, using Mitsubishi Paper Mills' set coated paper NM as the recording paper, the pixel diameter φ46.3 μ when the driving frequency F ₀ = 10 kHz.
I was able to obtain m. When the ink supply unit and the heating element substrate were attached and detached many times, it was observed that ink was attached near the contact portion of the heating element substrate, but due to the effect of the water repellent treatment, There was no way the ink could spread any further, blocked by the barrier.

[0050]

As is apparent from the above description, the present invention has the following effects. Effect corresponding to claim 1: Separation of the energy action part and the ink supply part may cause the energy action part to lose reliability such as dust adhesion and ink drying. However, since it can be easily separated and washed, an extremely reliable inkjet device can be realized. In particular, in the case of a general inkjet having a so-called nozzle, defects related to reliability such as clogging significantly increase with an increase in the number of nozzles, whereas as in the present invention, the energy acting portion is easily separated and washed. Reliability can be easily restored by adopting such a configuration,
It is most suitable for use in a multi-nozzle which conventional ink jets are not good at, especially in a large array page printer type ink jet recording apparatus which covers the entire printing width. Effect corresponding to claim 2: Since the ink supply unit is simply laminated on two substrates with a gap therebetween, the ink supply unit can be easily manufactured at an extremely low cost. Effect corresponding to claim 3: By stacking the two substrates of the ink supply section by shifting the positions of the ends thereof,
Therefore, the ink meniscus, which is a necessary requirement of the present invention, can be easily formed. Effect corresponding to claim 4: By providing a barrier between the adjacent energy acting portions, ink flying efficiency can be improved. As a result, it is possible to fly with low energy, moreover, high-speed ink flight is obtained, the jet is stable, the dot position accuracy on the paper surface is high, and high image quality recording is realized. Furthermore, since crosstalk between adjacent jets can be prevented, not only can jet instability and image quality deterioration due to crosstalk be prevented, but also adjacent energy action parts can be driven simultaneously without worrying about crosstalk. It also improves speed (conventional,
When there is crosstalk, the adjacent nozzles are not driven at the same time, and they are driven with a time delay, which causes a sacrifice in printing speed). Effect corresponding to claim 5: Since the amount of deviation between the ends of the first substrate and the second substrate of the ink supply unit is made larger than the height of the barrier near the heating element, the ink supply unit contacts the heating element substrate. When it is made to, it can prevent mutual damage. Effect corresponding to claim 6: Since the heating element substrate in the vicinity of the contact of the ink supply portion with the heating element substrate is water-repellent or oil-repellent treated,
During repeated attachment and detachment, the ink in the ink supply part may scatter around and permeate to stain the neighborhood, and the ink may move, causing an unexpected accident (permeation of ink into electrical contacts, etc.). Can be prevented. Effect corresponding to claim 7: This is another approach to the problem of the above 6, and since a barrier is provided to prevent unnecessary ink from moving and penetrating, the effect becomes more certain. . Effect corresponding to claim 8: A novel ink jet recording method different from the ink jet recording having a conventional nozzle that supplies ink from a separable ink supply section to an energy acting section to form an ink meniscus and ejects the ink. I was able to propose. Since it is a method without a nozzle,
It is advantageous for reliability such as clogging. Effect corresponding to claim 9: The above-mentioned novel ink jet reliability recovery method, in which the energy acting part and the ink supply part are separable, and the fact that no nozzle is provided as in the conventional case, The energy acting portion can be easily separated and can be easily cleaned by applying a cleaning liquid from the surface thereof, and extremely high reliability can be maintained. Effect corresponding to claim 10: Since the energy acting part is completely immersed in the cleaning liquid (jab attached state), the cleaning liquid can be surely spread to all parts, and the cleaning can be completed, High reliability can be maintained.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram for explaining an embodiment of an inkjet recording head according to the present invention.

FIG. 2 is a cross-sectional view of a main part for explaining an example of use of the inkjet recording head according to the present invention.

FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 is a diagram for explaining the operation principle of the inkjet recording head according to the present invention.

FIG. 5 is a perspective view illustrating an example of a heating element substrate having a barrier.

6A and 6B are views for explaining a method of forming the barrier 40 shown in FIG.

FIG. 7 is a diagram for explaining an example of a method of cleaning the heating element 4 section.

FIG. 8 is a diagram for explaining another example of the method for cleaning the heating element 4 section.

FIG. 9 is an exploded perspective view of an ink supply unit.

FIG. 10 is a diagram showing an arrangement example of the ink supply unit 7 and the heating element substrate 1.

11 is a diagram showing another example of the arrangement of the ink supply unit 7 and the heating element substrate 1. FIG.

FIG. 12 is a diagram for explaining an example of water repellent or oil repellent treatment.

FIG. 13 is a diagram for explaining another example of the water repellent or oil repellent treatment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heating element substrate (energy acting substrate), 2 ... Control electrode, 3 ... Ground electrode, 4 ... Heating element, 5, 6 ... Bonding pad, 7 ... Ink supply part, 8 ... First substrate, 9 ... Second Substrate, 10 ... Spacer, 11 ... Ink supply port, 12
... Ink supply liquid chamber, 13 ... Ink, 14 ... Bubbles, 15 ...
Ink columns, 16 ... Ink droplets, 20 ... Ink jet recording head support member, 21 ... Ink supply section holding section, 22 ... Heating element substrate holding section, 23 ... Chuck section, 24 ... Shaft,
25 ... Cleaning liquid recovery container, 26 ... Cleaning liquid injection nozzle, 27
... Air injection nozzle, 28 ... Cleaning container, 40, 50 ... Barrier.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B41J 3/04 103 B

Claims (10)

[Claims] 1. An energy acting substrate having a plurality of energy acting portions, and a common ink supply portion for pressing the energy acting portions to supply ink to the energy acting portions. An ink jet recording head characterized by being separable from an ink supply unit. 2. The ink jet recording head according to claim 1, wherein the ink supply unit is formed by stacking two substrates with a gap therebetween, and the gap serves as an ink supply liquid chamber. 3. The two substrates are stacked by shifting the positions of the end portions of the two substrates so that only one of the two substrates is in contact with the energy acting substrate.
The inkjet recording head according to 1. 4. The ink jet recording head according to claim 1, wherein a barrier is provided between adjacent energy acting portions of the energy acting. 5. The inkjet according to claim 4, wherein the barrier is set to a height that does not come into contact with one of the two substrates of the ink supply unit that does not come into contact with the energy acting substrate. Recording head. 6. The water-repellent or oil-repellent treatment is applied to the vicinity of a region of the two substrates of the ink supply section of the energy-applying substrate which is in contact with one of the two substrates. The inkjet recording head described. 7. The energy acting substrate is not required in a region near a region in contact with one of the two substrates of the ink supply unit, the region opposite to the energy acting unit sandwiching the substrate. The ink jet recording head according to claim 2, 3 or 5 or 6, further comprising a barrier for preventing ink from flowing out. 8. An ink supply means is pressed against an energy application substrate having an energy application part, ink is supplied from the ink supply means to the energy application part, and a signal is input to the energy application part according to image information. Then, the ink jet recording method is characterized in that the energy acting portion is driven to fly a part of the ink in the vicinity of the energy acting portion so that the ink adheres to a recording medium to perform recording. 9. An energy acting substrate having a plurality of energy acting portions, and a common ink supply portion for pressing the energy acting portions to supply ink to the energy acting portions, the energy acting substrate and the energy acting substrate. In a method for recovering the reliability of an inkjet recording head that is separable from an ink supply unit, the reliability of the inkjet head is characterized in that the ink supply unit is moved from the energy application substrate and a cleaning liquid is applied to the energy application unit. Recovery method. 10. An energy acting substrate having a plurality of energy acting portions, and a common ink supply portion for pressing the energy acting portions to supply ink to the energy acting portions, the energy acting substrate and the energy acting substrate. In a method for recovering the reliability of an inkjet recording head that is separable from an ink supply unit, the reliability of the inkjet head is characterized in that the ink supply unit is moved from the energy application substrate and the energy application unit is immersed in a cleaning liquid. Sex recovery method.