JPS61286152A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To obtain a charge-control type ink jet recorder securing stable operations by producing the flow of air to the direction of jetting ink droplets from the neighborhood of a nozzle. CONSTITUTION:A charger consists of a drive circuit 114a and a charge electrode 114b. When an electrostrictive vibrator 106 is operated at a fixed frequency by an oscillator 107, etc. the ink pressurized in an ink cavity 112 is jetted in the form of ink droplets at a fixed period from an ink nozzle 113, where weak air flow is occurred in the direction of jetting ink through an air outlet 108 from an air cavity 105 all the time in such a way as to fly ink straightly. No great change occurs in the direction of ink droplet flying even when more or less external disturbance, e.g., vibration, etc., take place. Therefore, ink droplets do not adhere to the charge electrode, thus securing stable operations of the charger.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a charge amount control type inkjet recording device.

[Conventional technology]

As an example of a conventional charge amount control type inkjet recording device, IBM 'Journrxl VOl, 28
．． /%3. MIZ? /1984 p, 300-30
6 can be mentioned. This schematic configuration is shown in FIG. 3-(c)). In the conventional operation, ink is pressurized by an ink pressurizing mechanism 201, passes through an ink cavity 202, is excited by an electrostrictive vibrator 205, and is constantly ejected as ink droplets from a plurality of nozzles 207 in the next cycle. During non-recording, the core ink droplets are charged by the charging electrode 208, and the direction of the nuclear ink droplets is deflected by the deflection device 210, and the droplets are directed to the gutter 21.
2 K is captured and sent to the ink pressure mechanism again via the ink recovery device 214. During recording, the charging device is driven by the input recording signal to selectively charge the ink droplets, and uncharged ink droplets are It reaches the recording paper 213 without being captured by the gutter and is recorded.

[Problems to be solved by the present invention]

However, with the above-mentioned conventional technology, in order to obtain high-density recording,
As shown in Figure 3-(b), the charging electrode 2 in the charging device
The pitch between 08 is very narrow at about 0.2 cranes,
In this way, the ink droplet passing between the nuclear charging electrodes is subjected to disturbances such as vibrations, and the flying direction of the ink (h) changes greatly, and the ink droplet (h) attaches to the charging electrode, and the nucleus is affected by the adjoining charged droplet. There are problems in that the electrodes may be short-circuited or the charged electrodes may be corroded, making it impossible to guarantee normal operation.

The present invention is intended to solve these problems, and its purpose is to control the amount of charge so that the ink droplets do not adversely affect the charging electrode and ensure stable operation even when subjected to external disturbances such as vibrations. An object of the present invention is to provide an inkjet recording device of the type shown in FIG.

[Means for solving problems]

The inkjet recording apparatus of the present invention is characterized in that it includes means for generating an air flow from the vicinity of the nozzle in the direction in which the ink droplets are ejected.

[Effect]

According to the above-described configuration of the present invention, even when a disturbance such as vibration occurs, the flight direction of the ink droplets does not change significantly due to the air flow, and therefore stable operation is possible without adversely affecting the charging electrode.

〔Example〕

FIG. 1 shows a configuration diagram of an embodiment of the present invention 0101
The air supply source consists of an air pump and a pressure stabilizer, and the air sent from the air supply source is passed through a pressure regulating valve 10.
2 and is supplied to the air channel 105 in the herad 104 which passes through the air inlet 103. On the other hand, after the ink is pressurized by the ink pressure mechanism 109, the ink is applied to the filter 110.
The ink is supplied to an ink cavity 112 in the head through an ink introduction port 111. An electrostrictive vibrator 106 is provided near the ink cavity.

The charging device is composed of a drive circuit 114cL and a charging electrode 114b, and application or non-application of a voltage between the charging electrode and the ink is controlled by the drive circuit which inputs signals of ON and OFF values. The charging electrode is formed in the vicinity of the air discharge port 108 corresponding to the ink nozzle 113, and its shape may be a circular hole type as shown in FIG. However, regarding the shape, the conventional example shown in FIG. There is always a high voltage (
2000 to 3000 V) is applied.

The electrostrictive vibrator 106 is energized from 10 to 70 by the oscillation device 107 or the like.
When excited at a constant frequency of about 1 FIz, the pressurized ink inside the ink cavity 112 has a nozzle diameter of about 3
Ink droplets are ejected from a 0-μm ink nozzle 113 at regular intervals, and after being selectively charged within a charging electrode by a charging device in response to an input recording signal, uncharged ink particles travel straight between deflection electrode plates. The charged ink particles then reach the recording paper 121, their flying direction is bent between the deflection electrodes, and they are captured by the gutter 120, pass through the ink recovery device 122 and the filter 123, and are pressurized again by the ink pressure mechanism 109 and reused. However, so that the ink hZ flies straight when it is ejected from the ink nozzle 113, a weak air current is constantly made to flow in the ink ejecting direction from the γ-chiyabity 105 through the air ejection port 108. Therefore, even if some disturbance such as vibration occurs, there will be no major change in the flight direction of the ink droplets due to the effect of the air flow, and as a result, the ink droplets will not adhere to the charging electrode and will not adhere properly. Even in the following cases, the air flow can dry the attached droplets, so that the operation of the charging device is not adversely affected.

By the way, the airflow energized within the charging electrode is caused by l! between the charging electrode and the deflection electrode plate. J116 is designed to be able to escape in the vertical direction as shown in Figure 1 through the entire length, but it will come in between the deflection electrode plates in some areas. If the air flow is too strong, it may affect the flying direction of the charged ink particles that should be bent between the deflection electrode plates, leading to inaccurate operation of the deflection device. Therefore, the air flow is controlled by the pressure regulating valve 102. It is necessary to adjust the strength to obtain normal movement.

〔Effect of the invention〕

As described above, according to the present invention, if a means for generating a weak air flow from the vicinity of the nozzle in the direction in which the ink droplets are ejected is provided, even if disturbances such as vibrations are received, the ink droplet h charging electrode will be adversely affected. This has the effect of ensuring stable operation without affecting the performance.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention. FIG. 2 is a main structural diagram of a charging electrode section in an embodiment of the present invention. FIG. 3-(cL) is a configuration diagram showing a conventional inkjet recording apparatus. Figure-(6) is a main structural diagram of the charging electrode and ink nozzle in Figure-6). 101... Air supply source 102... Air adjustment valve 103... Air inlet 104... Head 105... Air transmission 106. ..... Electrostrictive vibrator 107 ..... Oscillator 108 ..... Air discharge port 109 ..... Ink pressurizing mechanism 110 ..... Filter 111 ... Ink inlet 112 Ink cavity 113 Ink nozzle 114α Drive circuit 114b Charging electrode 115 Input Recording signal 116...Gap portion 117α...Deflection electrode plate 117b...Deflection electrode support portion 118...High voltage power source 119...Ink Droplet 120...Gutter 121...Recording paper 122...Ink collection device 201...Ink pressure mechanism 202...Ink cavity 203 . . . to 9 204 . . . Ink nozzle plate 205 . . . Electrostrictive vibrator 206 . . . Oscillator 207 . 08...Charging electrode 2Q9...Drive device 210...Deflection device 211...High voltage power supply 212...Gutter 215...・Recording paper 214...Ink collection device 215...Ink droplets or more

Claims (1)

[Claims] An ink pressurizing mechanism, a nozzle that ejects ink droplets to the outside by the pressurizing mechanism, a mechanism that charges the ink droplets, and a mechanism that controls the flying direction of the ink according to the amount of charge of the ink. In an inkjet recording device equipped with
An inkjet recording apparatus characterized by comprising means for generating an airflow from the vicinity of the nozzle in the direction in which ink droplets are ejected.