JPH04201570A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To obtain stable recording characteristics by a method wherein a fine-meshed substance is provided in an ink chamber so that the said substance can lead, by its capillary action, the ink inside the ink chamber to a supply port of an ink supply passage. CONSTITUTION:A fine-meshed substance 17 in an ink chamber 6 is placed along the chamber's internal wall on the side of an ink supply passage 13, and is arranged and fixed so that the said substance blocks a supply port of the ink supply passage 15. The fine-meshed substance 17 is so arranged that it works on its capillary action for leading of the ink inside the ink chamber 6 to the supply port of the ink supply passage 13. Therefore, the ink inside the ink chamber 6 can be led to the supply port of the ink supply passage 13 by capillary action of the fine-meshed substance 17 even in the case where the air in the ink chamber 6 increases to a certain amount, and the ink from an ink supply source 14 can be supplied steadily to the inside of the ink chamber 6 through the ink supply passage 13. Thereby stable recording characteristics are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inkjet recording apparatus that records characters, figures, etc. on a recording material by ejecting ink from a minute opening.

2. Description of the Related Art Conventionally, inkjet recording apparatuses that eject ink from minute openings using air flow and electrostatic force have been disclosed, for example, in Japanese Patent Laid-Open Nos. 57-120452 and 1982-1989.
A configuration as described in Japanese Patent No. 146860 is known. The conventional inkjet recording apparatus will be described below with reference to the drawings.

3 and 4 show a conventional inkjet recording apparatus, FIG. 3 is a sectional view in a normal operating state, and FIG.
The figure is a sectional view in a state where ink cannot be supplied. As shown in FIG. 3, an air nozzle plate 2 made of insulating material is attached to the tip of the outer wall of body member 1, and an ink nozzle plate 3 made of insulating material is attached to the tip of the inner wall. An air chamber 4 is formed between the inner walls, an air passage 5 communicating with the air chamber 4 is formed between the air nozzle plate 2 and the ink nozzle plate 3, and an ink chamber 6 is formed inside the ink nozzle plate 3. ing. An ink discharge lower is formed on the ink nozzle plate 3,
An air discharge port 8 is formed in the air nozzle plate 2 so as to face the ink discharge lower. An electrode 9 is provided on the outer surface of the air nozzle plate 2 on the outer periphery of the air discharge port 8, and an electrode 10 is provided on the inner surface of the ink nozzle plate 3 on the ink chamber 6 side on the outer periphery of the ink discharge lower. The air chamber 4 is communicated with an air supply source 12 through an air supply channel 11, and the ink chamber 6 is communicated with an inward supply source 14 through an ink supply channel 13. Further, the air supply source 12 is connected to an air supply channel 15.
It communicates with the upper part of the ink supply source 14 by. Electrodes 9 and 10 are connected to a signal source 16.

Next, the operation of the above conventional example will be explained.

Air is sent from the air supply source 12 to the air chamber 4 via the air supply channel 11, and flows through the air channel 5 at a constant flow rate 8 as an air layer while making a sharp bend. The ink flows out from the air discharge port 8 while forming a sharp bend near the air discharge port 8 and the ink discharge lower. On the other hand, the ink chamber 6 is supplied with ink from the ink supply source 14, and the ink in the ink supply source 14 and the ink chamber 6 is A certain pressure is applied to the As a result, when the inkjet recording device is not recording, the air pressure near the ink discharge lower caused by the air flow and the ink pressure inside the ink discharge lower are approximately equal, and the ink meniscus generated in the ink discharge lower is kept stationary. ing. Then, when a potential difference is generated between the electrodes 9 and 10, the meniscus of ink that is generated in the ink discharge lower is stretched in the direction of the air discharge port 8 due to the electrostatic force caused by this potential difference. Since a sudden change in pressure gradient occurs in the air flow path 5 from the ink discharge lower to the air discharge port 8 due to the air flow, when the ink meniscus of the ink discharge lower is stretched beyond a certain length, it is rapidly accelerated. , is discharged from the air discharge port 8.

Problems to be Solved by the Invention In the operation of an inkjet recording device, when first supplying ink to the ink chamber 6, it is difficult to completely fill the ink chamber 6 with ink, and the upper part of the ink chamber 6 is filled with ink. The reality is that there is some air that has escaped. The air in the ink chamber 6 poses a serious problem in an inkjet recording method using a piezoelectric vibrator because the pressure waves generated by the piezoelectric vibrator are absorbed by the air, leading to a situation in which ink cannot be ejected. On the other hand, in the inkjet recording method using air flow and electrostatic force shown in Fig. 3, recording is performed by the action of the force that draws out the ink, so this amount of air hardly poses a problem; This air absorbs pressure fluctuations propagated through the ink supply flow path 13, which has the effect of alleviating ejection instability factors.

However, when the inkjet recording device is not used for a long time, air gradually enters the ink chamber 6 from the joint with the ink supply channel 13, and air mixed with the ink is generated outside. air is accumulated in the ink chamber 6,
Furthermore, there is a strong possibility that air may be further accumulated in the ink chamber 6 due to impact being applied to the head and the ink meniscus formed in the ink ejection lower being torn. Air in the ink chamber 6 increases relatively easily to a certain amount. When the amount of air in the ink chamber 6 increases in this way, even if air pressure is applied to the ink supply source 14 from the air supply source 12 and the air in the ink chamber 6 is compressed, the ink formed in the ink discharge lower Ink chamber 6 with meniscus
Since the pressure inside the air chamber 4 and the inside of the air chamber 4 are almost balanced, a situation occurs in which the ink in the ink supply channel 13 is not completely supplied, as shown in FIG. When this happens, the recording becomes blurred or stops midway through.

The present invention solves the problems of the prior art as described above, and can prevent air from entering the ink supply flow path even if the amount of air entering the ink chamber increases.
Therefore, it is an object of the present invention to provide an inkjet recording apparatus that can smoothly supply ink from an ink supply source to an ink chamber in a stable state and can obtain stable recording characteristics.

Means for Solving the Problems The technical solution of the present invention for achieving the above object is as follows:
an ink chamber, an ink discharge port for discharging ink in the ink chamber, and an air discharge port facing the ink discharge port;
an air flow path provided between the ink discharge port and the air discharge port, an air supply source, an air supply flow path for supplying air from the air supply source to the air discharge port, and an ink supply source; - An ink supply flow path for supplying ink from the ink supply source to the ink chamber, an electrode disposed near the ink discharge port, and an electrode disposed near the air discharge port; In an inkjet recording device that performs recording by applying a potential difference between electrodes to draw out ink from the ink discharge port and causing it to fly through an air flow flowing out from the air discharge port, the ink chamber is provided with an ink chamber. A fine mesh body is provided so that the ink can be guided to the supply port of the ink supply channel by capillary action.

Therefore, according to the present invention, the ink in the ink chamber is guided to the supply port of the ink supply flow path by the capillary phenomenon of the fine network, so that even if the amount of air mixed into the ink chamber increases, the air can be prevented from entering the ink supply channel and forming a meniscus.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

Figures 1 and 2 show an inkjet recording device according to an embodiment of the present invention, with Figure 1 being a cross-sectional view during ink filling, and Figure 2 showing an increase in the amount of air mixed in the ink chamber after ink filling. It is a sectional view of a state.

In this embodiment, the same parts as those in the conventional example described above are given the same reference numerals, and the explanation thereof will be omitted, and the different configuration will be explained.

As shown in FIGS. 1 and 2, the fine mesh member 17 provided inside the ink chamber 6 is made of metal fiber, has a height that spans almost the entire height of the ink chamber 6, and has a height that spans almost the entire height of the ink chamber 6. The width is approximately 115 to 1/3 of the width of 6. This fine mesh body 17 is arranged and fixed along the inner wall surface on the side of the ink supply channel 13 so as to close the supply port of the ink supply channel 13 . And this fine mesh body 1
Reference numeral 7 allows the ink in the ink chamber 6 to be guided to the supply port of the ink supply channel 13 by capillary action.

The operation of the above configuration will be described below.

At the time of initial ink filling, as shown in FIG. 1, air flows into the ink chamber 6, as in the case of the conventional example shown in FIG.
However, since no meniscus is formed at the supply port of the ink supply channel 13,
It is possible to perform recording without any particular problem. As recording or storage continues for a longer period of time from this state, air enters the ink chamber 6 from the connection part of the ink supply channel 13, and an impact is applied to the head, causing the ink meniscus of the ink ejection lower Air may enter the ink chamber 6 due to breakage of the ink, or air may enter the ink chamber 6 due to generation of air from within the ink. Even when the air in the ink chamber 6 increases to a certain amount in this way, as shown in FIG. guided by. Therefore, ink is smoothly and stably supplied into the ink chamber 6 from the ink supply source 14 via the ink supply channel 13, and stable recording is possible.

If the fine mesh member 17 becomes too thick as it approaches the ink ejection lower, the resistance due to capillary action will increase, and in the case where ink is continuously ejected,
There is a risk that there will be an insufficient supply of ink for ejection from the ink ejection lower, leading to phenomena such as decreased density and blurring. Therefore, it is necessary to set the fine mesh body 17 so that there is a certain amount of space in which ink can accumulate in the region including the ink discharge lower inside the ink chamber 6. Further, as for the material of the fine mesh body 17, resin, ceramic, etc. can be used in addition to metal, and sintered metal can also be used as the metal. However, it is necessary to select these materials that have ink resistance and do not become a source of dust.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the ink in the ink chamber is guided to the supply port of the ink supply flow path by the capillary phenomenon of the fine mesh, so that the amount of air mixed into the ink chamber increases. Even if the ink supply channel is injected with air, it is possible to prevent air from entering the ink supply channel and forming a meniscus. Therefore, ink can be smoothly and stably supplied from the ink supply source to the ink chamber, and stable recording characteristics can be obtained.

[Brief explanation of the drawing]

Figures 1 and 2 show an inkjet recording device according to an embodiment of the present invention, with Figure 1 being a cross-sectional view during ink filling, and Figure 2 showing an increase in the amount of air mixed in the ink chamber after ink filling. 3 and 4 show a conventional ink jet recording apparatus, FIG. 3 is a sectional view in a normal operating state, and FIG. 4 is a sectional view in a state where ink cannot be supplied. 1...Body member, 2...Air nozzle plate, 3...
Ink nozzle plate, 4... air chamber, 5... air flow path,
6... Ink chamber, 7... Ink discharge port, 8... Air discharge port, 9.10... Electrode, 11... Air supply channel, 12 Air supply source, 13... Ink supply channel, 1
4 River ink supply source, 17...fine network. Name of agent Patent attorney Akira Koeji and two others Figure 1 Air supply source Figure 2 Air supply source - Figure 6 Figure 4

Claims (1)

[Claims] An inkjet recording device in which an ink chamber is provided with a fine mesh body so that ink in the ink chamber can be guided to a supply port of an ink supply channel by capillary action.