JPS59145155A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To make the compact construction of ink jet printer possible, by containing diaphragm type air pump or the like in the buffer tank of the air supply system feeding air current to an ink jet head. CONSTITUTION:A diaphragm type air pump 15 is contained in a buffer tank 21 and its intake vent 16 is connected to the air current inlet 18 of wall component 14 and introduces air. Its exhaust vent 17 is opened to the space part 20 enclosed by the wall component 14. The air current by the pump 15, the pulsation of which is absorbed by the space part 20 having sufficient volume, is fed to an ink jet recording head and an ink well from an air current outlet 19. Thus, the construction is compacted, at the same time the vibration and noise of diaphragm type air pump are effectively absorbed and the quiet air supply system can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inkjet recording device that utilizes air flow.

Structure of a conventional example and its problems FIG. 1 shows an inkjet recording apparatus by the present inventors that utilizes air flow and electrostatic force. An air outlet 1 is perforated in the insulating air nozzle plate 2, and the air nozzle plate 2
A conductive ink nozzle plate 3 is disposed in parallel with the ink nozzle plate 3, and ink discharge ports 4 are perforated in the ink nozzle plate 3 facing the air discharge ports 1. Air flow from the air supply source 22 flows into the air supply path 8, is made uniform in the annularly structured air chamber 9, and air flows from the periphery of the air layer 7 created by the air nozzle plate 2 and the ink nozzle plate 3. The air flows in and flows out from the air outlet 1. Since this air flow changes rapidly near the air outlet 1, a rapid change in pressure gradient occurs in the space from the ink outlet 4 to the air outlet 1.

On the other hand, an ink chamber 10 adjacent to the ink discharge port 4 communicates with an ink reservoir 11 via an ink supply path 6, and the ink reservoir! A constant pressure adjusted by the pressure adjustment mechanism 23 is applied to the ink in the ink 1111 by air pressure from the air supply source 22 . This is because when the inkjet recording device is not driven, the air pressure near the ink ejection port 4 and the ink pressure in the ink ejection port 4 or the ink chamber 10 are approximately equal, and the meniscus of the ink in the ink ejection port 4 is stationary. This is to make adjustments so that it is maintained at the same level.

The signal source 5 is connected to an electrode 12 provided around the air outlet 1 and the ink nozzle plate 3, and a potential difference is generated between the electrode 12 and the ink outlet 4. Due to the electrostatic force caused by this potential difference, the two mechanical supports of the ink generated at the ink ejection port 4 are stretched in the direction of the air ejection port 1. Furthermore, since a sudden change in pressure gradient occurs in the space from the ink discharge port 4 to the air discharge port 1, when the ink meniscus generated in the ink discharge port 4 is stretched beyond a certain length, the pressure gradient changes. It is accelerated by the air and flies from the air outlet 1.

FIG. 2 shows an inkjet recording device that utilizes the vibration force of an electromechanical transducer 13 that vibrates in response to an electric signal and air flow, and is disclosed in Japanese Patent Application Laid-open No. 51-37541 and Japanese Patent Publication No. 54-25416. A detailed explanation is given in Japanese Patent Publication No. 57-20905. That is, FIG. 2 shows an inkjet recording head of a so-called double-cavity ink-on-demand system described in Japanese Patent Publication No. 53-45698, in which an air discharge port 100 is provided in front of an ink discharge port 400. An air flow having a constant velocity is emitted, and the ink droplets ejected from the ink ejection opening 400 are accelerated by the vibration force of the electromechanical transducer 13, thereby enabling high-speed recording.

Similar to the apparatus shown in FIG. 1, in the apparatus shown in FIG.
The air supply source 2 is operated so that the air pressure near 00 and the ink pressure in the ink chamber 1.2.12' are approximately equal, and the ink meniscus generated at the ink ejection port 400 is kept stationary.
2. It is adjusted by the pressure adjustment mechanism 23. Comparing FIG. 1 and FIG. 2, although the principle of ejecting ink droplets is different, the air flow supply system has almost the same configuration.

Furthermore, an inkjet recording head that has its own ejection ability, such as the metal diaphragm inkjet head described in Japanese Patent Application Laid-Open No. 57-8163 or Sanyo Electric Technical Report VOL, 14 A11 '982, Some inkjet recording heads have improved performance by providing air discharge ports as described above and allowing air flow to flow out from the air discharge ports.

As an air supply source used in these inkjet recording apparatuses, a diaphragm pump as described in Japanese Utility Model Application Publication No. 53-60829 is suitable. Diaphragm pumps are popular because they are inexpensive and compact; however, they have the disadvantage of generating pulsating flow at a frequency corresponding to the number of rotations of the pump. Such pulsating flow affects the discharge state of the ink droplet from the ink ejection port and causes deterioration of the recorded image quality.However, as a means to remove the pulsating flow using a conventional diaphragm pump, the method shown in Fig. 3 is used. As shown, a diaphragm pump 22 and a pressure adjustment mechanism 23
A buffer tank 2 with a large capacity is installed in the air flow supply route between
1 was being established. However, about 0
．． In a diaphragm pump that generates a pulsating flow of 60 Hz with an amplitude of about 0.02 Kg/ctA, the pulsating flow can be reduced by approximately %.
In order to attenuate the inkjet ink, it is necessary to use a Noktufu 7 tank 21 having a volume of about 500 C0 or more, which has the disadvantage that the inkjet recording apparatus becomes large.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a compact printer that avoids increasing the size of an inkjet recording device when using the above-described tank.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inventive structure of the invention is to house the parts constituting an inkjet recording device in the buffer 7, to effectively utilize the space of the device, and to realize a compact printer.

Description of examples The present invention will be explained in detail below according to examples.

FIG. 4 shows an embodiment of the present invention. FIG. 4 shows an example in which a diaphragm pump is housed in a buffer tank.

In other words, the diaphragm pump 15 is housed in the sofa tank 21, and the diaphragm pump 16 is
The air inlet 16 is an air inlet 18 provided in the wall member 14.
It is connected to the air intake port 18 and takes in air through the air inlet 18. Further, the exhaust port 17 of the diaphragm pump 15 is open to a space 20 surrounded by the wall member 14, and air flow from the exhaust port 17 is sent into the space 20. The space 2Q has a sufficient volume, and the airflow with absorbed pulsation is sent out from the air outlet 19 and supplied to the inkjet recording head and the ink reservoir.

In the configuration shown in FIG. 4, the diaphragm pump 15 is housed in the buffer tank 21, so there is no need to install the diaphragm pump 15.

Diaphragm type maximum sprue 1 allows for smooth spatial arrangement.
5 and buffer tank 21 at separate locations, a much more compact design is possible.

Furthermore, when the diaphragm pump 15 is driven, it is accompanied by vibrations and noises that are synchronized with the rotation speed, but in the configuration shown in FIG. 4, these are absorbed in the buffer tank 21, without transmitting vibrations to other components. Further, since noise does not leak outside from the buffer tank 21, a very quiet air supply system can be realized.

In general, an inkjet recording device includes a recording system that is involved in recording using liquid droplets, and an electric system that is involved in the generation of electrical signals.
Mechanical systems involved in mechanical control can play a role as a device by integrating them, but what is housed in the buffer tank is not necessarily limited to the diaphragm pump, but can also include various components such as those mentioned above. You can also store it. For example, storing electrical components such as printed circuit boards in a sofa tank is also effective in making the device more compact.

Effects of the Invention As described in detail above, the present invention provides an inkjet recording device that utilizes an air flow. This allows an extremely compact inkjet recording device to be provided.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view showing the overall configuration of a conventional inkjet recording device, Fig. 2 is a partial sectional view showing the overall configuration of another conventional inkjet recording device, and Fig. 3 shows a conventional air supply system. The schematic diagram shown in FIG. 4 is a partially sectional side view of an air supply system in an embodiment of an inkjet recording apparatus according to the present invention. 14...Wall member, 15...Diaphragm pump, 16...Intake port, 17...Exhaust port,
18... Air inlet, 19... Air outlet,
20... Space section, 21... Buffer tank, 22 Air supply source, 23... Pressure adjustment mechanism. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure in 2 hits 9A Cow 21 22 Figure 4↑

Claims (1)

[Scope of Claims] 0) An inkjet head and an air supply system for supplying air flow to the head, and other components are housed in a buffer tank provided in the air supply system. An inkjet recording device featuring: (2) The inkjet recording apparatus according to claim 1, wherein the other component is a diaphragm air pump.