JPH03297655A - Ink flying recording method and its device - Google Patents

Abstract

PURPOSE:To obtain stabilized ink flying by enabling high quality printing to be performed under a state without dripping of an ink drop by a method wherein ink is made to fly upward from an ink liquid surface, and the flying ink is made to stick onto a recording part of a material to be recorded positioned above from the ink liquid surface. CONSTITUTION:All areas of a passage are filled by ink 19, and each heater part 9 is also covered by the ink 19. When each heating element layer 14 is electrified individually according to image information, a bubble is generated in ink liquid on the heated heating element layer 14. The ink 19 flies in a direction almost vertical to a surface of a heater part by driving force of this bubble. A recording head 1 is used in a positional relation wherein an ink flying direction is upward below recording paper 22 as a material to be recorded. By arranging the ink liquid surface of the recording head 1 upward thus, dripping of a flying ink drop is not generated, and high quality printing can be carried out. Further, fluctuation in height of the ink liquid surface due to a difference in water head is less, and stabilized ink flying can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ink jet recording method, which is one of the non-impact recording methods, and an apparatus therefor.

The conventional non-impact recording method generates negligible noise during recording, and is attracting attention for use in offices and the like. Among these, the so-called inkjet recording method is an extremely powerful method that enables high-speed recording and can record on so-called plain paper without the need for special fixing processing, and various methods have been proposed or have already been commercialized. It is put into practical use.

In this inkjet recording method, recording is performed by ejecting small droplets of a recording liquid called ink and attaching them to a recording medium. There are several types of methods depending on the control method used to control the direction.

The first method is disclosed, for example, in US Pat. No. 3,060,429. This is Te1e t
ype method, in which droplets of recording liquid are generated by electrostatic attraction, and the generated droplets are controlled by an electric field according to the recording signal to selectively adhere the droplets to the recording medium. It is for recording.

More specifically, by applying an electric field between the nozzle and the accelerating electrode, −
A small droplet of recording liquid electrically charged is ejected from a nozzle, and the ejected droplet is caused to fly between x and y deflection electrodes that are configured to be electrically controllable according to a recording signal, and is selectively deflected by changing the intensity of an electric field. This is to deposit small droplets onto a recording medium.

The second method is disclosed in, for example, US Pat. No. 3,596,275 and US Pat. No. 3,298,030. This is called the Sweet method, and uses a continuous vibration generation method to generate recording liquid droplets with a controlled amount of charge. This is to record on a recording medium by flying the recording medium over a distance.

Specifically, the orifice (discharge port) of a nozzle, which is a part of the recording head to which the piezo vibrating element is attached.
A charged electrode to which a recording signal is applied is placed in front of the orifice at a predetermined distance, and an electric signal of a constant frequency is applied to the piezoelectric vibrating element to mechanically vibrate the piezoelectric vibrating element. A droplet of recording liquid is ejected. At this time, charges are electrostatically induced in the ejected droplet by the charging electrode, and the droplet is charged with an amount of charge corresponding to the recording signal. When the droplet with a controlled amount of charge flies between the deflection electrodes to which a constant electric field 3- is applied, it is deflected according to the amount of charge added, and only the droplet that carries the recording signal is exposed. It will adhere to the recording medium.

The third method is disclosed, for example, in US Pat. No. 3,416,153. This method is called the Hertz method, and is a method in which an electric field is applied between a nozzle and a ring-shaped charging electrode, and small droplets of recording liquid are generated and atomized by a continuous vibration generation method to perform recording. That is, by modulating the electric field intensity applied between the nozzle and the charged electrode in accordance with the recording signal, the atomization state of the droplets is controlled, and the gradation of the recorded image is produced.

The fourth method is disclosed, for example, in US Pat. No. 3,747,120. This is S temm
This method is called the e method, and has a fundamentally different principle from the first to third methods. That is, in each of the first to third methods, the =4- droplets of the recording liquid ejected from the nozzle are electrically controlled while they are flying, and the droplets carrying the recording signal are selectively controlled. In contrast to recording by depositing a recording liquid onto a recording medium, in the STEMME method, recording is performed by ejecting small droplets of recording liquid from an ejection port in response to a recording signal.

In other words, in the STEMME method, an electrical recording signal is applied to a piezoelectric vibrating element attached to a recording head having an ejection port for ejecting recording liquid, and the electrical recording signal is converted into mechanical vibration of the piezoelectric vibrating element. According to the vibration, small droplets of recording liquid are ejected from the ejection port and attached to the recording medium.

Each of these four methods has its own advantages, but at the same time there are also problems that need to be solved.

First, in the first to third methods, the direct energy for generating droplets of recording liquid is electrical energy;
In addition, the deflection control of the droplets is also based on electric field control. Therefore, the first
Although this method is simple in structure, it requires a high voltage to generate droplets, and it is difficult to use a multi-nozzle recording head, making it unsuitable for high-speed recording.

The second method allows the recording head to have multiple nozzles and is suitable for high-speed recording, but it has a complicated structure, and the electrical control of recording liquid droplets is sophisticated and difficult. Satellite dots are likely to occur.

The third method allows recording with excellent gradation by atomizing small droplets of recording liquid, but on the other hand, it is difficult to control the atomization state. Further, there are drawbacks such as fogging occurring in the recorded image and difficulty in forming a recording head with multiple nozzles, making it unsuitable for high-speed recording.

On the other hand, the fourth method has relatively many advantages.

First, the configuration is simple. In addition, in order to perform recording by ejecting the recording liquid from the ejection opening of the nozzle on demand, among the small droplets that are ejected and flying as in the first to third methods,
There is no need to collect droplets that are not needed for image recording. Further, unlike the first and second methods, there is no need to use a conductive recording liquid, and there is an advantage that there is a large degree of freedom regarding the material of the recording liquid. However, on the other hand, it is difficult to make the recording head multi-nozzle because there are problems in processing the recording head and it is extremely difficult to miniaturize a piezoelectric vibrating element having a desired resonance frequency. In addition, because the mechanical energy of the mechanical vibration of the piezo vibrating element is used to eject and fly recording liquid droplets, this, combined with the difficulty of creating multiple nozzles, makes it unsuitable for high-speed recording. There is.

As described above, conventional methods have advantages and disadvantages in terms of structure, high-speed recording, multi-nozzle recording heads, generation of satellite dots, and fogging of recorded images, etc., and there are applications where the advantages can be demonstrated. It is subject to the restriction that it can only be applied to

However, such inconveniences can be almost eliminated by the inkjet recording method disclosed in Japanese Patent Publication No. 56-9429, proposed by the present applicant.

This heats the ink in the liquid chamber and generates bubbles.
This creates a pressure increase in the ink and causes the ink to fly out from a fine capillary nozzle to record.

A similar recording method is also disclosed in Japanese Patent Publication No. 61-59914. This method heats a part of the liquid in the liquid path that communicates with the ejection port to eject the liquid in a predetermined direction, causing film boiling, thereby reducing the flying droplets of the liquid ejected from the ejection port. The liquid droplets are then deposited on a recording medium to perform recording. Specifically, as shown in Figures 1 and 2 in the same publication, the recording liquid undergoes a rapid state change in the heat-acting part provided in the nozzle-shaped liquid path. The recording liquid is ejected from the ejection port by an acting force based on a change in state. According to the explanation in the same publication, a discharge port like this 8- has an inner diameter of 11
By thermally melting a cylindrical glass fiber with a wall thickness of 104 m, a discharge port with a diameter of 60 μm is formed. Furthermore, a method is also described in which the ejection port is formed separately from the liquid path, and then a hole is formed in a glass plate by electron beam processing, laser processing, etc., and then integrated with the liquid path. In any case, it is extremely difficult to industrially stably form such fine discharge ports with high precision. Further, according to the same publication, a recording head having different ejection ports is disclosed in FIGS. 3, 4, and 5 in the same publication,
As a method of forming the discharge port, a fine cutting machine is used to form the discharge port on a glass plate with a width of 60 μm, a depth of 60 μm, and a pitch of 250 μm.
It is described that a groove plate in which micrometer grooves are formed is bonded to a substrate provided with an electric/thermal converter section. However, in this case as well, the discharge ports to be formed are very fine, and when the grooves are formed using a fine cutting machine, chips and cracks often occur, resulting in a low yield. Also,
The end portions of the formed discharge ports cannot be made with high accuracy due to defects or the like. Furthermore, when the groove plate is bonded onto the substrate after the grooves are formed, the adhesive clogs the discharge port, resulting in a decrease in yield.

By the way, there is also an inkjet head described in Japanese Patent Laid-Open No. 62-253456. This is a device in which one slit-shaped nozzle is provided for a plurality of heating elements, instead of providing a nozzle hole for each heating element as in the conventional case. According to this, there is no need to form minute independent nozzles, resulting in a simple configuration.

Furthermore, according to Japanese Patent Application No. 1-225777 proposed by the present applicant, there is no need for a conventional nozzle plate or even the slit-shaped nozzle described in the above-mentioned Japanese Patent Application Laid-Open No. 62-253456. A novel ink jet recording method or device is disclosed. This is achieved by inputting a drive signal according to image information to an energy acting section placed within the ink liquid surface, causing bubbles to be generated in the ink by this energy acting section, and the effect resulting from the instantaneous growth of these bubbles. Ink is ejected from the ink liquid surface by force, and the ejected ink is attached to a recording medium. Structurally, it consists of an ink supply means, an ink level holding means for holding the ink supplied by the ink supply means, and an ink level holding means disposed within the ink surface to hold air bubbles that grow instantaneously in the ink. a signal input means for supplying a drive signal to the energy application section according to image information; and a signal input means located near the energy application section to prevent dispersion of pressure in a direction substantially parallel to the ink liquid surface. It is designed to provide a barrier for people to

With such a configuration, a drive signal corresponding to image information is inputted to the energy application section disposed within the ink liquid surface, and the energy application section generates air bubbles in the ink -11,-. The acting force caused by the instantaneous growth causes the ink to fly from the ink liquid surface, and the flying ink is attached to the recording medium, so it grows instantaneously.
After that, the ink can be ejected from the position corresponding to the energy application part by the force exerted by the bubbles that contract and disappear.Therefore, without using an orifice or slit-shaped nozzle, and without the generation of ink mist due to the bursting of bubbles. Therefore, it is possible to obtain a dot-like, high-quality clear image without fogging or the like. The structure for this purpose includes an ink supply means, an ink level holding means for holding the ink supplied by the ink supply means, and an ink level holding means disposed within the ink surface to prevent bubbles that grow instantaneously in the ink. an energy application section for generating energy, a signal input means for supplying a drive signal to the energy application section according to image information, and a signal input means located near the energy application section to prevent pressure from dispersing in a direction substantially parallel to the ink liquid surface. 12.
- Since there are no fine orifices or slit-shaped nozzles, there is no problem with clogging, and even if the ink dries or foreign matter such as paper dust adheres or gets mixed in, the original flight function can be restored by cleaning with cleaning liquid, etc. In addition, since it does not have minute orifices and does not require a bonding process to form them, it is low cost, and there are no problems with clogging caused by adhesives or defects in the process. Furthermore, by using photolithography to form the energy acting portion, etc., a high-density, high-integration configuration is possible.

Problems to be Solved by the Invention However, such a head without a nozzle (nozzle-less head) proposed by the present applicant and the Japanese Patent Application Laid-Open No. 62-2
Even with the head having a slit-shaped nozzle (slit-shaped nozzle type head) described in Japanese Patent No. 53456, there are many points that need to be improved in order to perform more stable and high-quality printing.

First, compared to conventional heads with independent nozzles (independent nozzle type heads), these heads have a characteristic of having a higher degree of freedom in controlling the ink liquid level (meniscus surface) because they do not have independent nozzles. As a result, it can be said that stability is somewhat low. That is, in the case of a nozzle-less type head or a slit-like nozzle type head, problems arise such as deterioration in image quality, as typified by the falling of flying ink droplets, or contamination of the head and its surroundings due to falling of ink droplets.

In addition, in the case of an independent nozzle type head, the nozzle has a strong force to hold the meniscus, so the meniscus position can be maintained relatively stably, but in the case of a slit nozzle type head or a nozzleless type head, it is difficult to maintain the ink liquid level. The force is weak. For this reason, for example, if the head is tilted significantly, or if the multi-nozzle head is used vertically, such as in a serial printer head with the nozzles arranged in the vertical direction,
Due to the difference in water head, the height of the ink liquid level differs between the upper heating element part and the lower heating element part, resulting in variations in ink flying conditions for each heating element.

Means for Solving the Problem In the invention as set forth in claim 1, a drive signal corresponding to image information is inputted to an energy application section disposed within the ink liquid surface, and this energy application section generates air bubbles in the ink. The ink is caused to fly upward from the ink liquid surface by the acting force caused by the instantaneous growth of the bubbles, and the flying ink is placed on the recording portion of the recording medium located above the ink liquid surface. I tried to attach it.

In the invention as claimed in claim 2, the device includes an ink supply means, an ink level holding means for holding the ink supplied by the ink supply means, and an ink level holding means disposed within the ink surface to momentarily contain the ink. an energy acting section that generates bubbles that grow upward; a signal input means that provides a drive signal to the energy acting section according to image information; and a signal input means located near the energy acting section that controls the ink level. , and a recording medium positioned above the ink liquid surface.

Function: In the above-mentioned ink jet recording method using a nozzle-less head, ink drops are ejected upward from the ink surface and attached to the recording portion of the recording medium positioned above, thereby preventing ink droplets from falling. High-quality printing is possible even when there is no

Further, there is little variation in the ink liquid level due to the difference in water head, and stable ink flight can be obtained.

Structurally, the nozzle-less head is simple, as the arrangement of the recording medium and the direction of ink flight can be modified.

16- Example An embodiment of the present invention will be described based on the drawings.

First, the outline of the above-mentioned nozzle-less type l\t structure already proposed by the present applicant will be explained with reference to Figs. 3 to 5. This recording head 1 is constructed using a trapezoidal manifold 4 having a hollow ink supply chamber 3 connected to an ink supply pipe 2 as a base material.

A heating element substrate 6 in which a slit 5 communicating with the ink supply chamber 3 is formed is fixed to the top of the manifold 4 . On this heating element substrate 6, comb-shaped barriers 7 are formed alternately on both sides of the slit 5, and a flow path 8 is formed between the barriers 7. These channels 8 are connected to the slit 5 in a staggered comb-like shape, contrary to the barrier 7 . Furthermore, heater sections (energy acting sections) 9 are formed on the heating element substrate 6 so as to be located on the innermost side of each flow path 8 . Therefore, when looking at the planar arrangement of the heater portions 9, they are arranged in a staggered manner on both sides of the slit as shown in FIG. Further, a fluid resistance section 10 having the same height as the barrier 7 is formed on the heating element substrate 6 so as to be located in the middle of each flow path 8 .

Furthermore, a frame-shaped holding member 11 that covers the periphery of the heating element substrate 6 is provided.
A film-like conductive lead 12 is provided on the manifold 4 and is held and fixed by the manifold 4.

Here, an example of the structure near the heater section 9 is shown in FIG.

This heater section 9 has a heat storage layer 13 formed on a heat generating body substrate 6, and a heat generating body MI4 on which a control electrode 15 and a ground electrode 1 are placed.
6, and the surface is further covered with a protective layer 17 and an electrode protective layer 18 to avoid direct contact with ink. Each heating element layer 14 has the control electrode 15
It is electrically connected to the thin film conductive lead 12 by wire bonding (not shown) via a ground electrode 16 and a ground electrode 16 . This thin film conductive lead 12 is connected to image information signal input means (not shown).

As a result, first, the ink supply f2 is replaced by the ink supply chamber 3.
The ink 19 (see FIG. 7) supplied to the ink passes through the fine slits 5 due to capillary action and fills the entire comb-shaped channel 8 surrounded by the barrier 7. Note that depending on the dimensions of the slit 5 and the flow path 8, it may not be possible to sufficiently supply and retain the ink 19 to the entire flow path 8 by capillary action alone. By adjusting the height between a certain ink tank (not shown) and the recording head 1, the difference in water head may be utilized.

In a steady state where the height of the ink liquid level is adjusted so that the entire flow path 8 is filled with ink 19 and each heater section 9 is also covered with ink 19, each When the heating element layer 14 is individually energized, bubbles are generated in the ink liquid on the heating element layer 14 that generates heat.

The propulsive force of these bubbles causes the ink 19 to spread to the surface of the heater section 9 (
The object will fly in a direction approximately perpendicular to the surface of the substrate.

This will be explained in detail with reference to FIG. In FIG. 7, the heater section 9 and its surroundings are shown in an enlarged scale, but electrodes and the like are omitted for the sake of simplicity.

FIG. 7(a) shows a steady state, in which ink 1 is distributed throughout the flow path 8.
9 is filled, and the heater section 9 is also covered with ink 19. When the heater section 9 is heated, the surface temperature of the heater section 9 rises rapidly, and the adjacent ink layer is heated until a boiling phenomenon occurs, resulting in a state where minute bubbles 20 are scattered as shown in FIG. .

Adjacent ink layers that are rapidly heated over the entire surface of the heater section 9 are instantaneously vaporized to form a boiling film as shown in FIG. 3(c). In a state where the bubbles 20 have grown in this manner, the surface temperature is 300 to 350°C, which is a so-called film boiling state.

Further, the ink liquid level of the ink layer 19 on the upper part of the heater section 9 rises as shown in the figure due to the driving force of bubble growth. Figure (d) shows a state in which the bubbles 20 have grown to the maximum at =20-, and the ink columns 21 have further grown from the ink liquid surface. The time required to reach the maximum bubble size depends on the structure of the head (heat generating substrate 6), the applied pulse conditions, etc., but usually takes about 5 to 30 psec after the pulse is applied. At the time when the bubbles reach the maximum size, the heater section 9 is already in a non-energized state, and the surface temperature of the heater section 9 is decreasing. The timing when the bubbles 20 reach their maximum is slightly delayed from the timing of the electric pulse application. FIG. 4E shows a state in which the bubbles 20 are cooled by the ink 19 and the like and begin to contract. At the tip of the ink column 21, it moves forward while maintaining the extruded speed, and at the rear end, the ink I9 flows back onto the ink liquid surface as the bubbles 20 contract, so that the ink column 21 is constricted as shown in the figure. arise. When the bubbles 20 further contract, the ink 19 comes into contact with the surface of the heater section 9, and the surface of the heater section 9 is further rapidly cooled, as shown in FIG. The ink column 21 is cut from the ink liquid surface and flies toward a recording medium (not shown) at a speed of 2 to 10+n/s. The flying speed at this time depends on the structure of the head (heating element substrate 6), the physical properties of the ink,
Although it depends on the applied pulse conditions, etc., when the flying speed is relatively slow (2 to 3 m/s), the ink 19 flies in the form of droplets, and when it is relatively fast (7 to 10 m/s), the ink 19 flies. 19 flies in the form of an elongated column. After this, the same figure (g
), the state returns to a steady state similar to that shown in FIG. 3(a), the entire flow path 8 is filled with ink 19, and the air bubbles 20 are also completely eliminated.

According to the flying principle of the present invention, the bubbles 20 for flying the ink 19 contract and disappear without bursting, so generation of ink mist due to bursting of bubbles is prevented, and image quality deterioration due to ink mist is prevented. do not have. Also, unlike recording ink in the form of a mist, recording is performed by flying the ink 19 in the form of droplets or elongated columns (in any case, as a lump of ink), so it appears as a single dot on the recording medium. It adheres and is recorded, resulting in clear images.

Note that in such a nozzle-less recording head 1, the heat generating substrate 6 is one of the important parts. First, the heating element substrate 6 itself is made of glass, alumina (AQ, O,
), those made of materials such as silicon are used. The heat storage layer 13 formed on the substrate 6 is made of, for example, a SiO□ layer, and in the case of a glass or alumina substrate, it is formed by a thin film forming method such as a sputtering method, and in the case of a silicon substrate, it is formed by a thermal oxidation method. Ru. The thickness of the heat storage layer 13 is preferably about 1 to 5 μm.

Further, as the material constituting the heating element layer 14, for example, a mixture of tantalum-3in, tantalum nitride, nichrome,
Silver-palladium alloys, silicon semiconductors, or borides of metals such as hafnium, lanthanum, zirconium, titanium, tantalum, tungsten, molybdenum, niobium, chromium, and vanadium can be used. Among these, metal borides are particularly preferred, and among these, hafnium boride is the most preferred in terms of characteristics, followed by zirconium boride, lanthanum boride, tantalum boride, vanadium boride, and niobium boride. becomes. The heating element layer 14 is formed using such a material by an electron beam method, a vapor deposition method, a sputtering method, or the like. The film thickness is determined based on its area, material, shape and size of the heat acting part, so that the amount of heat generated per unit time is the desired value.
Although it is set appropriately depending on the actual power consumption, etc., it is usually about 0.001 to 5 μm, preferably 0.01 to 1 μm.
The film thickness is approximately m.

The materials for the control electrode 15 and the ground electrode 16 may be the same as ordinary electrode materials, such as AQ, Ag y
A u! Ptl Cu etc. are used. These are formed in a predetermined position with a predetermined size, shape, and film thickness by a vapor deposition method or the like.

24- The protective layer 17 is for protecting the heating element layer 14 without preventing the heat generated in the heating element layer 14 from being effectively transferred to the ink 19 side, and is made of silicon oxide (Sin). ), silicon nitride, magnesium oxide, aluminum oxide, tantalum oxide, zirconium oxide, etc. are used. The manufacturing method is an electron beam method, vapor deposition method, sputtering method, etc. The film thickness is usually 0.01 to 10 μm, preferably 001 to 5 μl (especially 0.1 to 3 pm).
is considered optimal). The protective layer 17 is formed of one or more layers using these materials, and in addition to these layers, a protective layer 17 is made of these materials to protect the heater part 9 from the cavitation effect that occurs when the air bubbles 2o contract and disappear. It is desirable to form a metal layer such as Ta on the surface. Specifically, a metal layer such as Ta may be formed with a thickness of about 0.05 to 111 m.

Examples of materials for the electrode protective layer 18 include polyimide isoindoquinazolinedione (product name: PIQ, manufactured by Hitachi Chemical), polyimide resin (product name: PYRALIN,
DuPont), cyclized polybutadiene (product name: JSR)
-CBR, manufactured by Japan Synthetic Rubber Co., Ltd.), Photonease (trade name: manufactured by Toshisha Co., Ltd.), and other photosensitive polyimide resins are used.

In the case of a recording head l with such a structure or flight principle, as mentioned above, compared to an independent nozzle type head, since there are no nozzles, there is a higher degree of freedom in the ink liquid level, so depending on the conditions, the flying ink droplets may Deterioration in image quality as typified by dropouts, contamination of the head and its surroundings, or variations in ink flying conditions due to differences in liquid level may occur.

In this embodiment, as shown in FIGS. 1 and 2, the recording head 1 having the above-described structure is used in such a manner that the ink flying direction is directed upward under the recording paper 22 as the recording medium. It was designed to do so. That is, the recording head 1 having the structure shown in FIG. 5 and the like is used facing upward, so that the recording portion 23 of the recording paper 22 is positioned above the ink liquid level during recording. Note that the recording paper 22 is a roll paper, and is transported in the left-right direction by a pair of transport rollers 24.

By arranging the ink liquid level of the recording head 1 upward in this manner, the problem of droplets of flying ink droplets does not occur. By the way, if the ink level of the recording head L is not upward as described above but sideways, the ink may be ejected normally as shown in FIG. 13(a), but as shown in FIG. 13(b). In some cases, the ink droplets 25 fly as if they are dripping. In addition, in this embodiment method,
Even if the condition is such that ink droplets fall down due to changes in the ink liquid level, etc., the falling ink droplets 25 as shown in FIG. The image does not reach the recording unit 23, and no image disturbance occurs. Furthermore, even if a falling ink droplet is formed, the droplet that was about to fly upwards will return to the original ink level position due to its own weight. Therefore, since the receiver serves as a plate for ink droplets whose ink liquid surface is in a dripping state that is not suitable for recording, the recording head 1 and its surrounding area are not contaminated.

According to this embodiment, the recording head 1 is driven intermittently in order to perform not only the effect on falling ink droplets but also stable recording (in this case, the driving is performed under non-printing conditions). Even in the case of activating the ink liquid level, since the recording head 1 is oriented upward, the receiver for collecting unnecessary ink that is not used for recording serves as a tray.

Furthermore, if the multi-head of this embodiment is used in an almost vertical state as shown in FIG. hl is low, the height h2 at the bottom is high, and the ink liquid level height 8- is different between the upper and lower positions, so the ink flying conditions vary for each heater section 9, and high-quality printing cannot be expected. The independent nozzle type head is relatively less affected by such water head differences because the ink liquid level can be maintained for each nozzle. However, in the case of a nozzle-less multi-recording head 1, the degree of freedom in the ink liquid level is high, so this is greatly affected. Regarding this point as well, since it is used in an almost upward position as shown in Figures 1 and 2, even if it is a multi-type structure, there is little fluctuation in the liquid level due to the difference in water head, making it extremely stable. .

Regarding the arrangement of the recording head l, as shown in Figs. 1 and 2, due to the constraints at the time of printer design, etc.
Although there are cases where it is not possible to install the recording head 1 in a horizontal state facing upward, experiments have shown that the recording head 1 can be installed at an angle θ of 45° or less with respect to the horizontal plane, as shown in FIGS. 8(a) and (b). A similar effect was obtained even if the device was installed tilted upward.

Note that the above-described embodiment is not limited to the nozzle-less recording head 1 already proposed by the present applicant;
A slit-like nozzle type recording head 3 having a common slit-like droplet flying opening (nozzle) corresponding to a plurality of heater parts (energy acting parts) as shown in Japanese Patent No. 56.
The same applies to the case of 0. That is, FIGS. 9 to 12 show an example of the slit-shaped nozzle type recording head 3o shown in Japanese Patent Application Laid-open No. 1-97654, which is an improved version of the one described in Japanese Patent Application Laid-open No. 62-253456. In the case of the recording head 30 as well, it is preferable to dispose the recording head 30 downwardly and upwardly with respect to the recording paper 22.

Here, an overview of the structure of this recording head 30 and the principle of ink flying will be explained. FIG. 9 is a plan view of the slit nozzle plate 31, and FIG. 10 is a sectional view showing details of the slit nozzle 32 formed on the slit nozzle plate l. Nozzle plate 3
1 has a thickness of approximately several tens of microns, and a slit nozzle 32 having a width W is formed so as to penetrate the nozzle plate 31. The length a of this nozzle 32 is determined in consideration of the printing width. Such a slit nozzle plate 31 serves as the recording head 3.
0, it is attached to the surface as shown in FIGS. 11 and 12. In Figure 11, first,
Electric pulses are applied to the array-shaped heating element layer 14 (the heating element substrate 6 and the like are configured in the same manner as in FIG. Steam bubbles (
bubbles) 33 are generated. The pressure waves generated by this vapor bubble 33 are transmitted isodirectionally. Here, when the gap g between the nozzle plate 31 and the protective layer 18 is large, the fluid resistance becomes isodirectional, so that the flow of the ink 19 due to the volume change caused by the vapor bubble 33 is dispersed in the isodirection. Therefore, by making the above gap g equal to or smaller than the arrangement pitch of the heating elements 14 in the array direction, the heating elements 1
The fluid resistance to the slit nozzle 32 on the top 4 is reduced, and ink is ejected from the slit nozzle 32.

Even in such a slit nozzle type recording head 30, as in the case of the recording head 1, the slit nozzle 3
By setting the second side upward, it is possible to fly and record without ink droplets falling. Further, there is little variation in the ink meniscus position due to the difference in water head, and stable ink flight can be obtained at all positions of the heating elements 14.

In addition to the advantages of the nozzle-less head system, the ink droplet can be ejected in the direction of 32-, and the ejected ink is attached to the recording part of the recording medium located above the ink liquid level. It is possible to perform high-quality printing without dropping, and there is little variation in the ink liquid level due to water head differences, and stable ink flight can be obtained even in a multi-head structure. However, in a nozzleless head, the arrangement of the recording medium and the direction of ink flight can be modified, and a simple one is sufficient.

Effects of the Invention As described above, the present invention inputs a drive signal according to image information to an energy application section disposed within the ink liquid surface, causes this energy application section to generate bubbles in the ink, The force generated by the instantaneous growth of these bubbles lifts the ink from the ink liquid surface.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic sectional view showing the state of ink flying, FIG. 2 is a schematic perspective view showing the overall configuration, and FIG. 3 is a schematic exploded perspective view of the head. Fourth
The figure is an enlarged plan view of a part thereof, FIG. 5 is a sectional view taken along the line A-A in FIG. 4, and FIG. 6 is an enlarged sectional view showing the vicinity of the heater part.
Fig. 7 is a schematic sectional view showing the flight principle in order, Fig. 8 is a schematic sectional view showing a modification of the arrangement state, Fig. 9 is a plan view showing a modification of the recording head, and Fig. 10 is a part of it. 11 is a schematic sectional view showing the entire head, FIG. 12 is a plan view showing the arrangement of the heating elements, and FIGS. 13 and 14 are schematic sectional views showing conventional installation examples. 2... Ink supply means, 7... Barrier, 8... Ink liquid level holding means, 9... Energy acting section, 12...
- Signal input means, 19... Ink, 22... Recorded object 5. 23... Recording section 35 - - Horse 7 Figure q Figure J JO Hidden J J, 1 Figure 1.17 countries! −349=

Claims (1)

[Scope of Claims] 1. A drive signal corresponding to image information is input to an energy application section disposed within the ink liquid surface, and this energy application section generates bubbles in the ink, and the instant of the bubbles is generated. The ink is caused to fly upward from the ink liquid surface by the acting force due to the growth of the ink, and the flying ink is attached to a recording portion of the recording medium located above the ink liquid surface. An ink flying recording method. 2. An ink supply means, an ink level holding means for retaining the ink supplied by the ink supply means, and an ink level holding means disposed within the ink surface to cause bubbles that instantaneously grow in the ink to be directed upward. a signal input means for supplying a drive signal to the energy application section according to image information; and a signal input means located near the energy application section to prevent dispersion of pressure in a direction substantially parallel to the ink liquid surface. 1. An ink jet recording apparatus comprising: a barrier for preventing the ink from flowing; and a recording medium positioned above the ink liquid surface.