JPH05201031A - Liquid jet recording device - Google Patents

Abstract

PURPOSE:To perform a high picture quality printing with a rich gradation property by a method wherein an ink jet recording device is driven by a high response frequency to discharge and form micro ink drops stably and efficiently, and at the same time, the flying of the formed micro ink drops is stabilized, and the landing locations of the ink drops on a recording paper surface are kept with a high precision while varying a picture element diameter in response to image density information, concerning a liquid jet recording device. CONSTITUTION:A thermal resistor 1 is provided at a part of a liquid passage which connects to a discharge port 10, and a micro ink drop group 9 in response to the number of inputs is discharged by inputting a driving pulse once to several times in response to image density information to the thermal resistor 1, and stuck to a paper 5 to perform a gradation recording. At the same time, an air stream 8 is forcibly flown along a base plate 2 which constitutes a head 11, to cool the base plate 2, and it is constituted in such a manner that the air stream 8 holding heat is further passed to the paper 5 which is the discharge, flying direction of the ink drop group 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid jet recording apparatus, and more particularly to a liquid jet recording apparatus such as an ink jet printer capable of gradation recording.

[0002]

2. Description of the Related Art Conventionally, non-impact recording methods have been attracting attention because noise during recording is so small that they can be ignored. Among them, high-speed printing is possible, and so-called plain paper is specially fixed. The inkjet recording (liquid jet recording) method, which can perform recording without treatment, is an extremely effective recording method, and various methods have been proposed and improved so far.

In this type of liquid jet recording method, a droplet of a recording liquid such as ink is ejected and adhered to a recording member to perform recording. The method of generating the droplet of the recording liquid and It is roughly classified into several methods described below according to the method of controlling the flight direction of the generated recording liquid droplets. First, the first method is, for example, the one disclosed in US Pat. No. 3.060.429 (Tele type method), in which droplets of the recording liquid are generated by electrostatic attraction, and the generated recording is performed. Recording is performed by controlling the electric field of the liquid droplets according to the recording signal and selectively adhering the recording liquid droplets onto the recording member.

In this system, an electric field is applied between the nozzle and the accelerating electrode, a uniformly charged droplet of the recording liquid is ejected from the nozzle, and the ejected droplet can be electrically controlled according to a recording signal. Recording is performed by flying between the xy deflection electrodes configured as described above and selectively adhering recording liquid droplets onto the recording member due to a change in the strength of the electric field.

The second method is, for example, US Pat. No. 3.596.275.
As disclosed in Japanese Patent Publication (Sweet method), a droplet of a recording liquid whose charge amount is controlled is generated by a continuous vibration generation method, and the droplet is subjected to a uniform electric field. Recording is performed on the recording member by flying between the deflecting electrodes present. In this method, a charging electrode configured to apply a recording signal is provided for a predetermined distance in front of an orifice (hereinafter referred to as an ejection port) of a nozzle that is a part of a recording head provided with a piezoelectric vibrating element. The piezoelectric vibrating element is mechanically vibrated by applying an electric signal having a constant frequency to the piezoelectric vibrating element to eject a small droplet of the recording liquid from the ejection port.

A third method is, for example, US Pat. No. 3.416.153.
It is a method (Hertz method) as disclosed in Japanese Patent Publication, in which an electric field is applied between a nozzle and a link-shaped charging electrode, and a droplet of recording liquid is generated and atomized by a continuous vibration generation method for recording. is there. In this method, by modulating the electric field strength applied between the nozzle and the charging electrode according to the recording signal,
The atomization state of the droplets is controlled so that the gradation of the recorded image is produced and the image is recorded.

The fourth method is, for example, US Pat. No. 3.747.120.
This is as disclosed in Japanese Patent Publication (Stemme method). This method is fundamentally different in principle from the above-mentioned three methods, and each of the above-mentioned methods electrically controls the recording signal while ejecting a small droplet of the recording liquid ejected from the nozzle, thereby recording a recording signal. In contrast to the method of recording by selectively adhering the small droplets on the recording member, this Sweet method ejects and ejects small droplets of the recording liquid from the ejection port according to the recording signal. Record. In other words, in this method, a piezo vibrating element is attached to a recording head having a recording liquid ejection port, an electric recording signal is applied to this piezo vibrating element, and this electric recording signal is transferred to the piezo vibrating element. Recording is performed by changing to mechanical vibration and ejecting and ejecting a small droplet of recording liquid from the ejection port by the mechanical vibration and adhering it onto the recording member.

Although these four conventional methods have their respective characteristics, they still have problems. That is, in the first to third methods, the direct energy for generating a small droplet of the recording liquid is electrical energy, and the deflection control of the small droplet is also electric field control. Therefore, in the first method, , The structure is simple, but it requires a high voltage to generate droplets.
It is not suitable for high-speed recording because it is difficult to make the recording head multi-nozzle.

In the second recording method, the recording head can be multi-nozzle type and is suitable for high-speed recording, but the structure is complicated and it is difficult to electrically control the recording liquid droplets. However, there is a problem that so-called satellite dots are likely to be formed on the recording member. Even in the third recording method, it is possible to record an image with excellent gradation by atomizing the recording liquid droplets, but it is difficult to control the atomized state, and so-called fog occurs in the recorded image. In addition, there is a problem that it is difficult to use a multi-nozzle recording head and it is not suitable for high-speed recording.

The fourth recording method has many advantages over the above-mentioned three methods. That is, since the structure is simple and the recording liquid is ejected from the ejection port of the nozzle on-demand to perform the recording, the droplets ejected and ejected as in the first to third methods are not generated. It is not necessary to collect small droplets that were not required for image recording, and there is no need to use conductive recording liquid as in the first and second methods, and the degree of freedom in terms of the substance of the recording liquid is high. Is big.

However, even in the fourth recording method, there is a problem in processing the recording head, and it is difficult to reduce the size of the piezoelectric vibrating element having a desired resonance frequency, and it is difficult to make the recording head multi-nozzle. In addition, since the recording liquid droplets are ejected and ejected by the mechanical energy of mechanical vibration of the piezoelectric vibrating element, there is a problem that it is not suitable for high speed recording.

As described above, in the conventional liquid jet recording system,
There are merits and demerits in terms of device configuration, high-speed recording, multi-nozzle, and image quality due to occurrence of satellite dots and fog in recorded images, and in reality, it can only be applied to applications that take advantage of those merits. .. Among them, it is practically difficult to increase the density of the nozzles of the recording head and to collectively arrange the nozzles, for example, 16 nozzles / mm or more. The reason for this is that the structure of the recording head requires a large number of auxiliary devices and is complicated, or the limit of fine processing of the constituent elements is a limitation.

However, such an inconvenience can be solved by adopting the ink jet recording system (see Japanese Patent Publication No. 56-9429) previously proposed by the applicant of the present application. In summary, the ink jet recording method is one in which the ink in the liquid chamber is heated to generate bubbles, the ink pressure is increased, and the ink is ejected from the fine capillary nozzles for recording.

Further, Japanese Patent Publication No. 56-9429 discloses that, for example, a Bertier effect element is used as an example of cooling the recording head. Indicates what to do.
In this method, the head structure is considerably simplified, and since the heating element that is the source of the thermal pulse can be used in the semiconductor manufacturing process to perform highly precise processing, A number of inventions utilizing this principle have been proposed.

Further, Japanese Laid-Open Patent Publication No. 55-82663 discloses an ink droplet ejecting operation based on the same principle as the Japanese Patent Publication No. 56-9429, but it does not generate bubbles by a heating element. When ejecting ink droplets, the heat for generating bubbles was made in view of the problem caused by forming bubbles by separating gases such as dissolved oxygen in the recording medium liquid other than that. .. That is, since the bubbles in which the gas such as dissolved oxygen is separated are not the vapor of the recording medium liquid, they tend not to disappear rapidly even when the temperature drops and remain in the liquid chamber forever, and the pulse of the recording medium liquid Since the shock wave due to the vaporization is absorbed, the frequency response of droplet ejection is deteriorated. Therefore, in JP-A-55-82663, in order to suppress the generation of such unnecessary bubbles,
The temperature of the recording medium liquid is lowered by using a Bertier element or a refrigerator.

However, according to the results of the study conducted by the present inventors, it is found that such an unnecessary bubble is not generated by appropriately selecting the method of giving the high-speed heat flux for generating the bubble for discharging. Came. That is, by instantaneously applying an applied pulse to the heating element (within 20 μsec or less), only bubbles for ejecting ink droplets are generated and then instantly disappeared.
Unwanted bubbles do not occur as described in Japanese Patent Laid-Open No. 63, and there is no particular problem caused by them.

Further, in Japanese Patent Application Laid-Open No. 55-82663, the applicant of the present application discloses that a refrigerator is used in addition to the Bertier element described as one example of the cooling device in Japanese Patent Publication No. 56-9429. Although it has been proposed, the device itself has become very large-scale, and it was not always practical in terms of cost and operability. By the way, as described above, in the results of the study by the present inventors, although the problem of unnecessary air bubbles, which has been a problem in JP-A-55-82663, does not occur, heat is generated on the substrate on which the heating element is formed. Since it will be accumulated, wait for that heat dissipation,
Another problem has been found, in which the next pulse has to be applied, which slows down the response speed. However, in JP-A-55-82663, although the substrate temperature is mentioned, the problem is that the generation of unnecessary bubbles is a particular problem. Therefore, the problem that the increase in the substrate temperature causes must be solved (that is, The decrease in response speed due to having to wait for heat dissipation before giving the next pulse) has not been solved at all.

On the other hand, Japanese Patent Laid-Open No. 61-211045 is known. This is to maintain the temperature of the print head portion within an appropriate ink droplet formation range by using a heater and a blower. Generally, in the ink jet recording method, the ink droplet forming conditions greatly change due to changes in the physical properties of the ink (viscosity, surface tension, etc.), and as described in JP-A-61-211045, the ink properties are controlled by controlling the temperature. It is an indispensable technique to keep the value within a proper range.
In that sense, JP-A-61-211045 can be said to be an excellent invention. However, this Japanese Patent Laid-Open No. 61-211045 maintains the temperature of the print head portion within a proper ink droplet forming range by controlling the driving of the heater and the blower as described in the specification. An invention,
No mention is made of improvements to the slow response speed as described above. Also, although cooling the head portion with a blower is disclosed, it is not for increasing the response speed, but for maintaining the temperature of the print head portion within an appropriate ink droplet formation range. , It is not intended to improve the response speed. Further, although the blower is driven, it is not clear in what position the blower is arranged and in what direction the wind is blown.

[0019] Then, looking again at Japanese Patent Application Laid-Open No. 61-211045, it seems as if air is taken in from the side of the apparatus, but this merely shows the concept of temperature control. Since there is no concrete description on how to send the wind more effectively, it was impossible to implement it effectively as it is. Furthermore, Japanese Patent Publication No. 62-55990 discloses that
In the ink jet recording method using the same principle as Japanese Patent Publication No. 56-9429 previously proposed by the applicant of the present application, there is proposed a method of using residual heat generated by a head for drying a recording member. Specifically, a heat pipe is coupled to the upper part of the recording head, the other side of the heat pipe is coupled to a heat radiating plate, and the residual heat generated in the recording head is radiatively carried by the heat pipe, and the heat radiating plate records the member to be recorded. Is to dry. However, considering the complexity of the device by using the heat pipe, the cost increase, and the low efficiency due to drying by simply contacting the heat sink with the recording member, the device becomes large-scale. However, it was not a very good method because it could not be dried efficiently despite the high cost.

Further, JP-A-51-37541 and JP-B-60-59872.
JP-A-57-120452 and Japanese Patent Laid-Open Publication No. 57-120452 disclose a technique of ejecting / flying ink droplets by sucking ink by mechanical vibration of a piezo element or the action of an electric field. Then, a method for improving the stability of ink droplet ejection or the ejection efficiency is disclosed. These are conceptually excellent inventions, respectively, and when actually embodied, they are excellent inventions because the stability of ink droplet ejection of the recording head or the ejection effect is improved.
However, there is no description of how to configure a printer (or also called copier) using this recording head, and it was an excellent invention as a head unit, but when viewed as a printer, It has not necessarily been fully considered. Specifically, there have been insufficient studies on the direction of flowing air, how to escape the air after the air hits the paper, or the backflow of air or the generation of vortices. Furthermore, JP-A-51-37541
Japanese Patent Publication No. 60-59872 and Japanese Patent Publication No. 57-120452 are all disclosed in Japanese Patent Laid-Open No. 56-942 proposed by the applicant of the present application.
Since the ink droplet ejection principle is completely different from that of No. 9, there are advantages and disadvantages of the ejection principle described in JP-A-56-9429, that is, instantaneous ejection (advantage) by heat and accumulation of heat. There was no mention of any defects (cons) that would cause it.

On the other hand, in US Pat. No. 4.503.444, as in the above-mentioned Japanese Patent Laid-Open No. 56-9429, bubbles are generated in the recording medium liquid by utilizing heat, and the bubbles are generated. There is a disclosure of a method of changing a pixel diameter by using a technique of ejecting ink from a minute nozzle by pressure. This is a technique in which minute ink droplets are generated at a very high driving frequency, and the pixel diameter is changed by changing the number of minute ink droplets forming one pixel according to image density information. To obtain a very small pixel diameter using this technique, one very small ink droplet is ejected and ejected to form a pixel on the recording paper. Further, in order to obtain a large pixel diameter, a plurality of the above-mentioned very small ink droplets are made independent or are ejected in a state in which they are connected and ejected to form one pixel on the recording paper. In other words, the above technique forms one pixel using a plurality of minute ink droplets that fly independently or in a continuous manner, so that from very small pixels to large pixels,
A desired pixel diameter can be obtained according to the image density information.

[0022]

However, in the above-mentioned conventional liquid jet recording apparatus, especially in US Pat. No. 4.503.444, the size of a pixel formed by changing the number of minute ink droplets is changed. Although the concept of changing the
There was no specific description of what kind of conditions should be used for recording. Therefore, the applicant of the present application conducted an experiment on this point using a printer head having two kinds of array densities of 300 dpi and 360 dpi (corresponding to 12 lines / mm and 14 lines / mm). When the drive frequency of the pulse input to the printer head is 4 to 8 kHz,
I was able to perform the ink ejection operation, but 30 to 50 kHz in order to further increase the frequency and form minute ink droplets.
It was found that driving at a very high frequency results in no ink droplets being ejected, and only a fine mist (fog) drifting.

Even if fine ink droplets can be generated as described in the above-mentioned US Pat. No. 4.503.444, since such fine ink droplets have a small mass, they are affected by ambient disturbance. There is a problem that it is easy and it is very difficult to stably eject the ejected minute ink droplets. In particular, the stability of flight of the ink droplet depends on whether or not the ink droplet can accurately reach a desired position on the target recording paper surface, and is very important for high-quality printing.

The present invention has been made in view of the above conventional problems, and drives an ink jet recording apparatus at a high response frequency to stably and efficiently eject and form fine ink droplets, and the formed fine droplets. It stabilizes the flight of ink droplets and changes the pixel diameter according to the image density information, while maintaining the ink droplet landing position on the recording paper surface with high accuracy and performing high-quality printing with rich gradation. An object of the present invention is to provide a liquid jet recording apparatus that can be used.

[0025]

The invention according to claim 1 is
Recording near the energy acting portion, having an ejection opening, a liquid passage communicating with the ejection opening, an energy acting portion provided in a part of the liquid passage, and a liquid chamber communicating with the liquid passage. A liquid jet recording apparatus that causes a part of a liquid to undergo a state change due to heat, causes a part of the recording liquid to be ejected and ejected from the ejection port based on the state change, and adheres to a recording medium for recording. , Energy is input to the energy acting portion one to a plurality of times according to image density information, and the discharge amount of the recording liquid is changed according to the number of times of input to adhere to the recording medium to perform gradation recording. A recording liquid discharge amount control means and a part of the liquid path are formed, and an air flow is forcibly made to flow along a substrate having the energy acting portion or a supporting substrate holding the substrate, to the substrate or the supporting substrate. The accumulated heat with the air flow Is moved to the serial discharge port side, the ejection of the recording liquid air stream having a heat, characterized by comprising an air flow jetting means, the flow in the flight direction.

The invention according to claim 2 is characterized in that the air flow ejected by the air flow ejecting means is caused to flow so as to hit the recording surface of the recording medium. The invention according to claim 3 is characterized in that the air flow ejected by the air flow ejecting means is caused to flow in the ejection and flight directions of the recording liquid, and the ejected recording liquid flies in the air flow. To do.

The invention according to claim 4 is characterized in that the flow velocity of the air flow ejected by the air flow ejecting means is variable. The invention according to claim 5 is characterized in that the flow velocity of the air flow ejected by the air flow ejecting means is variable in accordance with the image information. According to a sixth aspect of the present invention, the recording medium on which the recording liquid discharged and jetted is adhered for recording is arranged so that the air flow ejected by the air flow ejecting means quickly escapes along the recording surface. It is characterized by having done.

According to a seventh aspect of the present invention, the air flow ejected from the air flow ejecting means is a laminar flow.

[0029]

According to the first aspect of the present invention, the recording liquid discharge amount control means controls the energy acting portion to be 1 depending on the image density information.
-By inputting energy multiple times under a certain condition, minute ink droplets that are much smaller than the ink droplets used for normal binary recording are stably ejected, and the number of times corresponding to the number of times of energy input is increased. It is possible to change the amount of the recording liquid adhering to the same portion of the recording medium by the ink droplet group and change the pixel diameter to perform gradation recording. Then, when the minute ink droplet group is ejected and ejected, the heat around the ink jet head is taken by forcibly flowing the air flow along the substrate or the supporting substrate by the air flow ejection means, and the heat is taken. An air flow is discharged in the ejection direction of the recording liquid. This makes it possible to cool the periphery of the inkjet head, improve the recording response speed due to the heat storage effect of the head, stabilize the flight of minute ink droplets ejected from the head by the air flow, and The landing position becomes highly accurate, and high-quality gradation recording can be performed.

According to the second aspect of the present invention, the air flow ejected by the air flow ejecting means absorbs heat around the ink jet head and has a high temperature. Therefore, the air flow is directed to the recording surface of the recording medium. By flowing so as to hit the printed surface, the printed surface can be efficiently dried, and the blurring of pixels can be eliminated to improve the image quality. In particular, when performing gradation recording, if a plurality of minute ink droplets are used to obtain a pixel larger than the pixel for binary recording, the drying time will be longer than usual, but a hot air flow will be applied. Since it is applied to the recording surface of the recording medium, the drying time is short, which is effective.

According to the third aspect of the invention, the air flow ejected by the air flow ejecting means is caused to flow in the ink droplet ejection and flight directions.
Since the ink droplets are made to fly in the air flow,
Even minute ink droplets are not easily affected by disturbance and the flight is stabilized, so the accuracy of the landing position on the recording paper surface is improved, and high-quality gradation recording can be performed. In the invention of claim 4, the flow velocity of the air flow ejected by the air flow ejecting means is made variable, so that the optimum air flow velocity for each device is selected even if the head structure of the liquid jet recording device is different. It is possible. Further, the amount of heat generated by the heating resistor varies depending on the driving condition of the head, but even in that case, the head can be driven in an optimum state by changing the air flow velocity and performing optimum cooling. ..

When minute ink droplets are made to fly in the air flow, by changing the flow velocity of the air flow,
It is possible to select an air flow velocity suitable for the minute ink droplets to be ejected, the flight stability of the ink droplets is improved, and high-quality gradation recording is possible. According to the fifth aspect of the invention, the flow velocity of the air flow having heat ejected by the air flow ejecting means is made variable according to the image density information, so that it takes a longer time to dry the ink droplet as the pixel diameter increases. By changing the air flow velocity, drying is always performed in the optimum state, and image bleeding is suppressed as much as possible to improve image quality.

According to the sixth aspect of the invention, the recording paper on which the ejected and ejected minute ink droplets are adhered for recording is curved so that the airflow ejected by the airflow ejecting means quickly escapes along the paper surface. Alternatively, by arranging the airflow at different angles to the paper surface, the airflow will not swirl back on the paper surface, and the airflow that carries the flying ink drops will not be disturbed. The flight is stable, the accuracy of the landing position is improved, and high-quality gradation recording can be performed.

In the seventh aspect of the invention, since the air flow ejected from the air flow ejecting means is made into a laminar flow, the flight stability of the ink droplets is not disturbed, the flight is stable, and the landing position accuracy is improved. It is possible to improve and perform high-quality gradation recording.

[0035]

EXAMPLES Examples of the present invention will be described below. First, the principle of ink ejection will be described based on FIG. 9, which is an explanatory view of the principle of ink ejection by a bubble jet.
In FIG. 9, 21 is a lid substrate, 22 is a heating element substrate, and 23 is a selection.
(Independent) electrode, 24 is a common electrode, 25 is a heating element (heater),
26 is an adjacent ink layer (ink), 27 is a bubble, and 28 is a flying ink droplet.

(A) is a steady state, in which the surface tension of the ink 26 and the external pressure are in equilibrium on the orifice surface. In (b), the heater 25 is heated and heated until the surface temperature of the heater 25 rapidly rises and a boiling phenomenon occurs in the adjacent ink layer 26, and minute bubbles 27 are scattered.

(C) is a state in which the adjacent ink layer 26 that has been rapidly heated on the entire surface of the heater 25 is instantly vaporized to form a boiling film, and the bubble 27 is grown. At this time, the pressure in the nozzle rises by the amount of growth of the bubbles, the balance with the external pressure on the orifice surface is lost, and the ink column begins to grow from the orifice. In (d), the bubble 27 is grown to the maximum, and the ink 26 corresponding to the volume of the bubble is pushed out from the orifice surface. At this time, no current is flowing through the heater 25, and the surface temperature of the heater 25 is decreasing. The maximum value of the volume of the bubble 27 is slightly delayed from the timing of applying the electric pulse.

(E) shows a state in which the bubble 27 is cooled by ink or the like and starts to contract. At the tip of the ink column, the ink column moves forward while maintaining the pushing speed, and at the rear end, ink contracts due to the contraction of the air bubbles, causing the ink to flow backward from the orifice surface into the nozzle, resulting in a constriction in the ink column. .. In (f), the bubble 27 is further contracted, the adjacent ink layer 26 is in contact with the heater 25 surface, and the heater 25 surface is further rapidly cooled. At the orifice surface, the external pressure is higher than the internal pressure of the nozzle, so a large meniscus has entered the nozzle. The tip of the ink column becomes an ink drop 28, which flies toward the recording paper at a speed of 5 to 10 m / sec.

(G) is a process in which the ink 26 is supplied (refilled) to the orifice again by the capillary phenomenon and returns to the state of (a), and the bubble 27 is completely extinguished. The thermal inkjet device using such a principle, when ejecting the ink droplet 28 (forming a pixel),
So-called binary recording when ejection is not possible is possible.

When so-called multi-value recording, in which the size of a pixel is changed by using the same principle as described above, can be performed as follows. FIG. 10 is a diagram showing the relationship between the drive pulse input to the heating resistor, the ejected ink droplet, and the diameter of the formed pixel. In FIG. 10, 29 is a driving pulse, 30 is a flying ink drop, and 31 is a pixel on the paper surface. FIG. 10 (a) is the same as the case of FIG. 9, and the flying ink amount is almost always uniform. Yes, this is the case where binary recording is performed.

However, in FIGS. 10 (b) to 10 (e), one or more pulse energies are applied at fine intervals, and one or more independent ink droplet groups 30a to 30d are formed accordingly. In addition, depending on the conditions, these small ink droplet groups 30
The a to 30d are not independent but become a hump-shaped bulge according to the input pulse energy number, and may fly as one continuous ink column (see the ink droplet group 9 in FIGS. 1 and 3). In this case, the input pulse energy is smaller than that in the case of FIG. 10 (a), so that the ink droplets formed are also smaller. Since this small pulse energy is applied to one or a plurality of pulses at a high frequency (several to several tens of kHz), individual minute ink droplets are continuously formed as shown in FIGS. 10 (b) to (e). Alternatively, they are ejected as a single connected ink column to fly and adhere to the surface on the recording paper side to form pixels. Since these minute ink drop groups 30a to 30d adhere to the paper within a short time, one pixel is formed by a plurality of ink drops. That is, the size of the pixel (pixel diameter) is changed according to the number of ink drops, and gradation recording can be performed.

Specifically, in one recording head,
When binary record information is input as the character information,
When multi-valued record information as image information for gradation expression is input, the operation shown in (a) is performed and the operation shown in Fig. 10 (b) to (e) is performed according to the image information. It is possible to deal with all kinds of image information by properly selecting the image information.

By the way, at such a high driving frequency, 1
-When a plurality of pulse energies are applied to the recording head for recording, ink droplets cannot always be ejected as described above. As described above, according to the experiments conducted by the inventors of the present application, in a recording head having a relatively large nozzle diameter with an arrangement density of 300 dpi to 360 dpi, even if ink can be ejected at a drive frequency of about 4 to 8 kHz, Driving at a very high frequency of more than 10 kHz and 30 to 50 kHz results in that ink is not ejected and only mist drifts.

The inventors of the present application have paid attention to this fact, and one of the reasons why the ink droplets can be ejected when the driving frequency is low and cannot be ejected when the driving frequency is high is that the inertia of the ink is a major factor. I noticed. In other words, what affects the speed of the phenomenon of ejecting ink, that is, the phenomenon in which a mass of ink having a certain amount of mass moves, is the case where the mass is large and the mass is large (large ink drop)
Is difficult to eject due to the action of inertia, but when the mass is small (small ink droplet), it is difficult to receive the action of inertia,
It can be easily discharged.

The inventors of the present application noticed this point, and in order to perform the ink ejection operation by driving at a very high drive frequency exceeding 10 kHz as described above, the nozzle diameter is reduced and the ejected ink droplet is It is important to make it less susceptible to the effects of inertia by reducing the mass of
In this embodiment, the nozzle diameter of the recording head is 24 μm × 24 μm, the array density is 600 dpi (corresponding to 24 lines / mm), and the nozzle diameter is 20 μm × 20 μm, and the array density is 80
We made a device with 0 dpi (31 lines / mm equivalent) and conducted an experiment to see if the ink ejection operation could be performed frequently and at high speed. As a result, the maximum driving frequency of 600 dpi is 30
It can discharge ink droplets up to kHz, 800
In the case of dpi, it was possible to eject ink droplets up to a maximum drive frequency of 42 kHz.

Of course, these recording heads can perform stable ink ejection operation even at a low frequency of 10 kHz or less, which has been conventionally performed.
FIG. 11 is a view for explaining the structure of the bubble generating means using a heating resistor, in which 32 is a heating resistor, 33 is an electrode, 34 is a protective layer, 35 is a power supply device, and the heating resistor 32 Examples of useful materials for forming the element include, for example, tantalum-Si.
O ₂ mixture, tantalum nitride, nichrome, silver-palladium alloy, silicon semiconductor, or hafnium, lanthanum, zirconium, titanium, tantalum, tungsten,
Examples thereof include sulfides of metals such as molybdenum, niobium, chromium and vanadium.

Among the materials forming the heating resistor 32, metal sulfide can be mentioned as an especially excellent one. Among them, hafnium sulfide has the most excellent characteristic, and then sulfide is The order is zirconium, lanthanum sulfide, tantalum sulfide, vanadium sulfide, and niobium sulfide. The heating resistor 32 can be formed by using a method such as electron beam evaporation or sputtering using the above materials. The film thickness of the heating resistor 32 is determined according to the area, the material, the shape and size of the heat acting portion, and the actual power consumption so that the amount of heat generated per unit time is as desired. But in the normal case,
The thickness is 0.001 to 5 μm, preferably 0.01 to 1 μm.

As the material forming the electrode 33, many of the commonly used electrode materials are effectively used, and specific examples thereof include Al, Ag, Au, Pt and Cu. Using a method such as vapor deposition at a predetermined position,
It is provided with a predetermined size, shape, and thickness. The characteristic required for the protective layer 34 is that the heat generating resistor 32 is protected from the recording liquid without hindering effective transfer of the heat generated by the heat generating resistor 32 to the recording liquid. Examples of useful materials for forming the protective layer 34 include silicon oxide, silicon nitride, magnesium oxide, aluminum oxide, tantalum oxide, zirconium oxide, and the like. Can be formed. The thickness of the protective layer 34 is usually
0.01-10 μm, preferably 0.1-5 μm, optimally 0.1-
It is desirable that the thickness is 3 μm.

Next, the manufacturing process of the bubble jet head using the above principle will be described with reference to the manufacturing process diagrams of FIGS. 12 (a) to 12 (e). The examples shown here relate to a discharge port, a flow path, and a common liquid chamber made of a cured film of a photosensitive resin. In the figure, 36 is a substrate, 37 is an ink ejection pressure generating element, 38 is a thin film, 39 is an adhesive layer, 40 is a dry film photoresist, 41 is a photomask, 42 is an adhesive, 43 is a flat plate, and 44 is a groove. is there.

In the process of FIG. 12 (a), silicon, glass,
For the purpose of providing a desired number of ink ejection pressure generating elements 37 such as heating elements and piezo elements on a substrate 36 made of ceramic, plastic, metal, or the like, and further providing ink resistance and electrical insulation as necessary. , A thin film 38 of SiO ₂ , Ta ₂ O ₅ glass or the like. The ink discharge pressure generating element 37
A signal input electrode (not shown) is connected to the.

In the step shown in FIG. 12B, the adhesive layer 39 is applied to the surface of the substrate 36 having the ink discharge pressure generating element 37 by about 1
It is formed with a thickness of about 5 μm to 5 μm. At this time, a desired liquid adhesive is applied to the surface of the substrate by a known method such as a spinner coating method, a dip coating method, or a roller coating method, and then semi-cured.

Specifically, in the case of the spinner coating method, an adhesive having a viscosity of 2 to 15 CP is applied at 1000 to 5000 rpm. In the case of the dip coating method, the substrate 1 is dipped in an adhesive having a viscosity of 20 to 30 CP and then withdrawn at a constant speed of 20 to 50 cm / min. Furthermore, in the case of the roller coat method,
Adhesive with a viscosity of 100 to 300 CP is applied between rollers at a speed of 60 to 200 cm /
Apply in minutes.

The kind of the adhesive used here is not particularly limited as long as a predetermined adhesive force is exhibited, but in the present invention, the photo-curable resin adhesive is especially recommended for the convenience of production. is there. Thus, as the photo-curable resin adhesive suitable in the present invention, for example, an unsaturated polyester resin and a monomer, dimer or oligomer compound having at least one unsaturated double bond in the molecule (methyl methacrylate, styrene) is used. , Diallyl phthalate, etc.) or an unsaturated polyester and at least one unsaturated double bond-modified resin such as silicone, urethane, or epoxy having at least one unsaturated double bond in the end chain group or main chain, or with the monomer, dimer, It is composed of a combination of oligomers and the like. Further, in the present invention, when the adherend interface of these adhesives is formed of a compound based on Si, a silane coupling agent is mixed with the above-mentioned adhesive, or the surface of the substrate 36 is preliminarily treated with silane. Treatment with a coupling agent is also effective.

In the subsequent step shown in FIG. 12 (c), after the surface of the adhesive layer 39 of the substrate 36 obtained through the step shown in FIG. 12 (b) is cleaned and dried, the adhesive layer 39 On top of, 80
A dry film photoresist 40 (film thickness of about 25 μm to 100 μm) heated to about 100 ° C. to 100 ° C. is laminated under a pressure of 1 to ³ kg / cm ² at a speed of 0.3 to 0.4 f / min. At this time, the dry film photoresist 40 is fused to the adhesive layer 39. Thereafter, the adhesive layer 39 is irradiated with ultraviolet rays to be fully cured according to the properties of the adhesive used. After that, even if a considerable external pressure is applied to the dry film photoresist 40, the dry film photoresist 40 is not separated from the substrate 36.
Then, as shown in FIG. 12 (c), after overlaying a photomask 41 having a predetermined pattern on the dry film photoresist 40 provided on the substrate surface, the photomask 41 is formed.
Exposure from above. At this time, the installation position of the ink ejection pressure generating element 37 and the position of the pattern must be aligned by a known means.

FIG. 12D is an explanatory view showing a step of dissolving and removing the unexposed portion of the exposed dry film photoresist 40 with a developing solution containing a predetermined organic solvent.
Next, the dry film photoresist left on the substrate 36
In order to improve ink resistance of the exposed portion 40P of 40, heat curing treatment (eg, heating at 150 to 250 ° C. for 30 minutes to 6 hours) or UV irradiation (eg, 50 to 200 mW / tm ² , or it) The above ultraviolet ray intensity) is performed to sufficiently enhance the polymerization and curing reaction.

It is also effective to use both the heat curing and the curing by ultraviolet rays. By the way, the adhesive layer used
When 39 remains in the groove 44, it is eluted into the ink to change the quality of the ink, clog the ink passage, or
Since the function of the ink ejection pressure generating element 37 may be impaired, a dry film photoresist is used in the present invention.
At the time of pattern exposure for 40 (FIG. 12 (c)), the adhesive layer 39 is also photo-cured at the same time, and the uncured adhesive layer 39 is dissolved and removed together with the dry film photoresist 40 in the subsequent developing step with an organic solvent (FIG. 12). (d)).

In FIG. 12 (e), a flat plate 43 for adhering to the ceiling is adhered to the substrate 36 in which the groove 44 serving as an ink passage is formed by the dry film photoresist 40P cured after the above sufficient polymerization. It is a figure which shows the place fixed simply by crimping. In the step shown in FIG. 12 (e), the concrete method for constructing the ceiling is as follows: 1) A flat plate 43 made of glass, ceramics, metal, plastic or the like is spinner-coated to a thickness of 3 to 4 μm with an epoxy adhesive. After that, the adhesive 42 is preheated to be a so-called B stage, and the adhesive 42 is attached to the cured photoresist film 40P to be fully cured. Alternatively, 2) there is a method in which a flat plate 43 of a thermoplastic resin such as an acrylic resin, an ABS resin, or polyethylene is directly heat-sealed onto the hardened photoresist film 40P.

By the way, in the above process, the adhesive layer 39
Substrate of photoresist cured film 40P for each of the case where is an acrylic resin photocurable adhesive applied to a thickness of 1 μm and the acrylic resin photocurable adhesive applied to a thickness of 2 μm Peel strength from 36 (Test A)
And the photoresist cured film 40P (1 mm
When the residual rate (Test B) on the surface of the substrate 36 when dipped (× 1 mm) in water at 80 ° C. for 1 week was measured, the results were as shown in Table 1.

[0059]

[Table 1]

Here, the appearance of the recording head after the step of FIG. 12 (e) is shown in FIG. 13 as a schematic perspective view. In the figure, 45 is an ink supply chamber, 46 is an ink liquid flow path, and 47 is an ink supply chamber 45.
Shows a through hole for connecting an ink supply pipe (not shown). In the above-mentioned examples, a dry film type, that is, a solid type was used as the photosensitive composition (photoresist) for forming the groove.
The present invention is not limited to this, and a liquid photosensitive composition can of course be used.

As a method for forming this photosensitive composition coating film on a substrate, in the case of a liquid, a method using a squeegee used when producing a relief image, that is, a film having the same height as a desired photosensitive composition film thickness is used. The method is to put the wall around the substrate around the substrate and remove the excess composition with a squeegee. In this case, the suitable viscosity of the photosensitive composition is 100 CP to 300 CP. In addition, the height of the wall around the substrate needs to be determined in consideration of the reduction in evaporation of the solvent component of the photosensitive composition.

On the other hand, in the case of fixing, the photosensitive composition sheet is heated and pressure-bonded onto the substrate to adhere. It is more advantageous to use a fixed film type in terms of handling and controlling the thickness easily and accurately.
Examples of such a solid substance include, for example, RIST, a permanent photopolymer coating manufactured by DuPont.
ON, solder mask 730S, same 740S, same 750
There are photosensitive resins commercially available under the trade names of FR, 740FR, and SMI. In addition, as the photosensitive composition to be used, many of the photosensitive compositions used in the general field of photolithography such as photosensitive resins and photoresists can be mentioned. Examples of these photosensitive compositions include diazoresins, P-diazoquinones, photopolymerization type photopolymers using vinyl monomers and a polymerization initiator, dimerization type photopolymers using polyvinyl cinnamate and a sensitizer. Polymer, mixture of orthonaphthoquinone diazide and novolac type phenol resin, mixture of polyvinyl alcohol and diazo resin, polyether type photopolymer obtained by copolymerizing 4-glycidyl ethylene oxide with benzophenone or glycidyl chalcone, N, N-dimethylmethacryl A copolymer of an amide and, for example, acrylamidobenzophenone,
Unsaturated polyester type photosensitive resin [eg APR (Asahi Kasei), Tevista (Teijin), Sonne (Kansai Puint)
Etc.], an unsaturated urethane oligomer-based photosensitive resin, a photosensitive composition in which a photopolymerization initiator and a polymer are mixed in a bifunctional acrylic monomer, a dichromic acid photoresist, a non-chromium water-soluble photoresist, a polysilicic acid Examples thereof include vinyl photoresists and cyclized rubber-azide photoresists.

FIG. 1 is a diagram showing the configuration of a liquid jet recording apparatus according to an embodiment of the present invention, which is a cross-sectional view taken along a plane parallel to the ejection and flight directions of ink droplets, and FIG. 4 is an external perspective view of the cover of FIG. 3, FIG. 3 is a cross-sectional view showing a configuration of a liquid jet recording apparatus according to another embodiment of the present invention, and FIG. 4 is an external perspective view of the head of FIG. In these figures,
1 is a heating resistor, 2 is a substrate, 3 is an opening, 4 is a cover, 5
Is a recording medium (paper), 6 is a bubble, 7 is heat that escapes from a heating element to the substrate, 8 is an air flow, 9 is an ink liquid group, 10 is an ejection port, 11
Is a thermal inkjet head (also simply referred to as a head), 12 is a support substrate, and 13 is ink (recording liquid).

The principle of this liquid jet recording apparatus is shown in FIGS.
A brief description will be given based on FIG. 9, or the thermal inkjet head shown in FIG.
A cover 4 in which an opening 3 is formed so as to correspond to the orifice portion is provided outside (corresponding to 11). The openings 3 corresponding to the orifices do not have to be independent openings corresponding to the individual orifices, but are common to a plurality of high density (eg, 16 / mm or more) orifice rows. It may be an opening elongated in one orifice arrangement direction (see FIG. 2).

Then, the thermal ink jet head 11
There is a gap between the cover and the cover 4, as shown in FIG.
The air flow 8 flows there. Air flow 8
Is located behind the head 11 in the ink droplet ejection direction (see FIG.
From the right) to the front (left in FIG. 1). Air flow 8
The purpose of flowing the heat as described above is one of the substrate 2 on which the heating resistor 1 is formed, and the substrate 2 in the case of FIG.
Is to cool the support substrate 13 holding. In the thermal inkjet head 11, part of the heat generated by the heating resistor 1 is used to generate bubbles, and the rest is the surrounding ink.
13 or escapes to the substrate 2 or the supporting substrate 13 on which the heating resistor 1 is formed. In FIG. 1 and FIG. 3, the heat 7 escaping to the substrate 2 and the supporting substrate 13 is conceptually shown by an arrow.

Such heat 7 is gradually accumulated as the printing is continued, and due to the temperature rise of the ink 13 and the accompanying changes in the physical properties of the ink (viscosity, surface tension, etc.), the conditions for bubble formation and the ink droplets are increased. This is not preferable because the ejection conditions change. It is conceivable to wait until such a change in the conditions is cooled to the extent that it does not pose a practical problem due to natural heat dissipation before performing the next printing, but this is not preferable because the printing speed becomes slow.

It is desirable that the flow velocity (or flow rate) of the air flow 8 to be flown in the present invention is variable. This is because the amount of heat accumulated in the head 11 varies due to different printing conditions, different head drive frequencies, different ambient temperatures in the operating environment, and so on. FIG. 3 shows an embodiment in which the head 11 is held by the supporting substrate 12, and the material of the supporting substrate 12 is one having a high thermal conductivity such as aluminum.
As shown in FIG. 3, it may be a flat plate shape for simply holding the head 11, but for example, as shown in FIG. 4, the support substrate 12 is formed in a fin shape to increase the surface area,
It is even better if the heat dissipation characteristics are improved. In this case, in order not to disturb the flow direction of the air flow 8, it is desirable that the fin grooves are formed in the ink droplet ejection direction. Although FIG. 4 shows only the head 11 and the cover 4 shown in FIG. 2 is omitted, in actuality, the cover 11 as shown in FIG. It's flowing.

In addition to the above-mentioned effects, the present invention has other effects. This will be explained below. As shown in FIG. 1 and FIG. 3, in the present invention, unnecessary heat generated in the heat generating resistor 1 is carried toward the recording medium (paper) 5 by flowing the air flow 8, and the heat is generated. The air stream 8 hits the paper 5. The main purpose of doing this is to accelerate the drying of the printing surface. Drying is promoted by simply sending air to the wet (or damp) paper after printing, but the effect is doubled by sending a hot air stream as in the present invention. Moreover, in the present invention, the unnecessary exhaust heat is simply used without providing any special means for applying heat to the air flow, so that the configuration is very simple. Also in this case, it is desirable for optimal drying to make the strength of applying the heated airflow to the paper variable according to the printing state.

Still another effect of the present invention is ejection of ink droplets, stabilization of flight, and reduction of energy. In the present invention, by causing the air flow to flow in the ink droplet flying direction,
It is possible to assist the ejection and flight of ink droplets. That is, by entraining the airflow 8 in the flight direction, the air resistance in the ejection / flying direction is reduced as compared with the case of ejecting / flying in a windless state, and the ejection / flying can be performed with small energy. Alternatively, if the energy is the same, the entrained air flow 8 helps to increase the flight speed of the ink droplets, enabling stable flight.

In particular, in the present invention, FIG.
As described in (e), one or more minute ink droplets, which are much smaller than those in normal binary recording, are ejected according to the image information. Compared with the case of a large ink droplet ejected at the time of value recording, the stability of the flight is likely to be hindered, and the accompanying air flow 8 is made to flow in the flight direction,
It is essential to get a stable flight.

In the present invention, with the assistance of the entrained air stream 8,
Although such an effect can be obtained, there are some points to be aware of rather than simply flowing air. It is described below. Generally, air is a viscous fluid, and its flow includes laminar flow and turbulent flow. Now, when considering the flow in a circular pipe, the flow in which the fluid particles in each layer in the pipe flow parallel to the tube axis is called laminar flow, and the fluid particles in each layer enter each other and are mixed irregularly. The ongoing flow is called turbulent flow. More quantitatively, when the kinematic viscosity of the fluid is γ, the average flow velocity is u, and the inner diameter of the pipe is d, a dimensionless number represented by the following equation R = ud / γ
If ds) is less than a certain value, it is called laminar flow, and if it is more than that, it is called turbulent flow. Also, the Reynolds number at the transition from turbulent flow to laminar flow and laminar flow to turbulent flow is called critical Reynolds (Rc), and according to the research of many scholars, Rc = 2310 (in the case of ordinary critical Reynolds number) , The lower critical Reynolds number, so the value of Rc is also the lower critical Reynolds number here).

Specifically, how to flow the layer solution is, for example, when the inner diameter d of the tube is 2 mm, the kinematic viscosity γ of air is about 0.165 cm ³ / s at 1 atm and 35 ° C. Therefore, by modifying the above equation and substituting these values, u = Rc × γ / d = 2310 × 0.165 (cm ³ / s) / 2 (mm) ≈19.1 (m / s) A laminar flow can be obtained if the air flow rate is about 19 m / s or less.

As described above, in the turbulent flow, the fluid particles in each layer enter each other and are turbulently advancing while mixing irregularly.
It is not preferable to carry the ink droplets of the present invention during flight. In the present invention, one of the purposes is to stabilize the flight of ink droplets, so it is preferable to flow a laminar flow. However, the air flow velocity may be variable, and a turbulent flow may be used as long as the head is cooled or the printing surface is dried without causing the ink droplets to fly.

Another point to be noted is that, after the flowing air stream hits the paper, the air flow quickly flows along the paper surface. FIG. 5 is a diagram showing a positional relationship between a recording medium and a head that causes an unfavorable air flow. As shown in FIG. 5, it can be seen that the airflow 8 discharged from the front surface of the head 11 does not flow quickly along the paper surface 5 and thus forms a vortex.

FIG. 6 is a view showing a state where the recording surface of the recording medium is curved, and FIG. 7 is a diagram showing a state where the head is inclined with respect to the recording medium. As shown in FIG.
A slight curve is provided, or as shown in FIG. 7, the positional relationship between the head 11 and the paper 5 is made to have an angle, for example, so that the airflow 8 can quickly flow along the paper surface 5. Therefore, it is possible to prevent the vortex from being generated. Further, this is an example in which even if a vortex occurs, it can be stopped to a small vortex that does not affect the flying ink droplets.

In addition to the relationship between the paper 5 and the head 11 as described above, for example, as shown in FIG. 8, the corner portions of the parts such as the cover 4 and the head 11 are arranged so that the airflow 8 flows smoothly. It is desirable to chamfer or process it into a curved shape (the solid line portion in FIG. 8 is processed into a corner portion shape as shown by a broken line). Based on the configuration as described above, specific implementation conditions in each example and specific effects therefor will be described below.

Example 1 A recording head as shown in FIG. 3 (nozzle diameter of 24 μm × 24 μm
With an array density of 600 dpi (the shape of the cover is as shown in Fig. 2), the length of the opening in the lateral direction is 2 mm, and the air velocity is 10 m / s. Than the above, the flight speed of ink drops is improved (5 m / s → 7.
1 m / s), and the head position accuracy on the paper surface was within ± 10 μm. Further, the response frequency of the pulse group of the head was improved from 2 kHz to 3.8 kHz, the pulse generation frequency of the pulse group at this time was 30 kHz, the pulse width was 3 μs pulse, and the pulse voltage was 30 V. Furthermore, regarding the dry condition of the paper surface, 25 seconds after the completion of printing
After 45 seconds, there was no blurring of the image even after rubbing by hand.

Example 2 In the case of Example 1, the length of the opening in the lateral direction was 1.4 mm and the air flow rate was 13 m / s. The ink droplet flight speed is
5 m / s → 8.5 m / s, other characteristics are shown in Example 1
As well as improved. Example 3 In the case of Example 1, the lateral length of the opening is 3 mm,
When the air flow velocity was set to 25 m / s, the positional accuracy of the printed dots deteriorated (within ± 100 μm), and image disturbance was observed.

[0079]

According to the first aspect of the invention, gradation recording can be performed by stably ejecting minute ink droplets and changing the pixel diameter by the number of ink droplet groups corresponding to the number of energy inputs. it can. Then, the airflow flowing along the substrate or the supporting substrate cools the periphery of the inkjet head to improve the response speed of recording, and the minute ink droplets flying along with the airflow fly stably. The landing position on the recording medium becomes highly accurate, and high-quality gradation recording can be performed.

According to the second aspect of the present invention, the print surface is efficiently dried by the air flow having heat to eliminate pixel bleeding and improve the image quality even when gradation recording is performed. be able to. According to the third aspect of the present invention, even minute ink droplets are less susceptible to the influence of disturbance, the flight is stable, the landing position accuracy on the recording paper surface is improved, and high-quality gradation recording can be performed. ..

According to the fourth aspect of the invention, even if the head structure of the liquid jet recording apparatus or the head driving conditions are different, the air flow velocity suitable for each condition is selected and the head is driven in the optimum state. Can be made Even when minute ink droplets are made to fly in the air flow, by selecting an air flow velocity suitable for the minute ink droplets to be ejected, the flight stability of the ink droplets is improved and high image quality is achieved. Gradation recording is possible.

According to the fifth aspect of the present invention, the air flow velocity is made variable according to the image density information to reduce the variation of the drying time depending on the pixel diameter of the ink droplets, and the image can be recorded even in gradation recording. Bleeding can be minimized to improve the image quality. According to the invention of claim 6, the air flow quickly escapes along the recording paper surface, so that the air flow does not swirl on the paper surface, and the accompanying air flow is not disturbed.
The flight of ink drops is stable, the accuracy of landing position is improved, and high-quality gradation recording can be performed.

According to the seventh aspect of the invention, the laminar air flow stabilizes the flight of ink droplets, improves the accuracy of landing position, and enables high-quality gradation recording.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a liquid jet recording apparatus according to an embodiment of the present invention.

FIG. 2 is an external perspective view of the cover shown in FIG.

FIG. 3 is a sectional view showing the configuration of a liquid jet recording apparatus according to another embodiment of the present invention.

4 is an external perspective view of the head of FIG.

FIG. 5 is a diagram showing a positional relationship between a recording medium and a head that causes an unfavorable air flow.

FIG. 6 is a diagram showing a state where a recording surface of a recording medium is curved.

FIG. 7 is a diagram showing a state in which a head is inclined with respect to a recording medium.

FIG. 8 is a cross-sectional view showing the shapes of a cover and a head that generate a preferable air flow.

FIG. 9 is a diagram illustrating the principle of ink ejection by a bubble jet.

FIG. 10 is a diagram illustrating a relationship between a drive pulse input to a heating resistor, an ejected ink droplet, and a formed pixel diameter.

FIG. 11 is a diagram for explaining the structure of a bubble generating means using a heating resistor.

FIG. 12 is a manufacturing process diagram of a bubble jet head according to an embodiment of the present invention.

13 is an external perspective view of the recording head of FIG.

[Explanation of symbols]

 1 Heating Resistor 2 Substrate 3 Opening 4 Cover 5 Recording Medium (Paper) 6 Bubble 7 Heat 8 Air Flow 9 Ink Drop Group 10 Ejection Port 11 Thermal Inkjet Head (Head) 12 Support Substrate 13 Ink (Recording Liquid)

Claims (7)

[Claims] 1. An energy source comprising: a discharge port; a liquid path communicating with the discharge port; an energy acting portion provided in a part of the liquid path; and a liquid chamber communicating with the liquid path. A state change due to heat is caused in a part of the recording liquid in the vicinity of the action portion, and based on the state change, a part of the recording liquid is ejected and ejected from the ejection port and adhered to a recording medium to perform recording. In a liquid jet recording apparatus, energy is input to the energy acting portion one to a plurality of times according to image density information, and the ejection amount of the recording liquid is changed according to the number of times of input to adhere to the recording medium. A recording liquid discharge amount control unit for performing gradation recording and a part of the liquid passage, forcing an air flow along a substrate having the energy acting portion or a supporting substrate holding the substrate, Heat accumulated on the substrate or supporting substrate Is moved to the discharge port side along with the airflow,
A liquid jet recording apparatus comprising: an air flow jetting unit that discharges the recording liquid and discharges the recording liquid in a flight direction. 2. The liquid jet recording apparatus according to claim 1, wherein the air flow jetting means causes the air flow jetted by the air jetting means to flow so as to hit the recording surface of the recording medium. 3. The liquid jet recording apparatus according to claim 1, wherein the air flow ejected by said air flow ejecting means is caused to flow in the ejection and flight directions of said recording liquid, and the recording liquid ejected in the air flow is ejected. A liquid jet recording apparatus characterized in that. 4. The liquid jet recording apparatus according to claim 1 or 3, wherein the flow velocity of the air flow ejected by the air flow ejecting means is variable. 5. The liquid jet recording apparatus according to claim 2, wherein the flow velocity of the air flow ejected by the air flow ejecting means is variable according to the image information. 6. A liquid jet recording apparatus according to claim 3, wherein an air flow ejected from said air flow ejecting means is rapidly recorded on said recording medium on which recording is performed by adhering said recording liquid ejected and jetted. A liquid jet recording apparatus, which is arranged so as to escape along a surface. 7. A liquid jet recording apparatus according to claim 1, wherein the air flow ejected from said air flow ejecting means is a laminar flow.