JPH032670B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic fluid recording device that applies electrostatic attraction to a magnetic fluid (hereinafter referred to as ink) to cause the ink to fly and print on a recording surface. The objective is to provide a device that can always produce stable, high-quality printed images with little dirt.

Conventionally, in this type of magnetic fluid recording device,
The drawback was that ink adhering to areas other than the recording electrodes flew onto the recording surface due to the electrostatic force caused by the induced charge, resulting in noise and dirt in the print. A conventional magnetic fluid recording device will be described below with reference to the drawings.

1 and 2 show an outline of a conventional magnetic fluid recording device. Recording electrode 1 is placed on base 2.
is mounted on the recording electrode 1, and a bump magnet 3 is mounted on the recording electrode 1. The recording electrode 1 is magnetized by a bump magnet 3, and a magnetic fluid 4 is held on the recording electrode 1 by magnetic force, and near the tip of the recording electrode 1 there is a magnet as shown in FIG. A magnetorheological ridge 4 as shown is formed. A control electrode 5 is arranged facing the recording electrode 1 at a predetermined interval, and between the recording electrode 1 and the control electrode 5 is a high-voltage power source 7 and a voltage that controls ON/OFF of the voltage corresponding to the image signal. A predetermined high voltage is applied for a predetermined time by a voltage drive circuit 8. The recording paper 6 is placed in contact with the control voltage 5, and when a high voltage is applied between the control electrode 5 and the recording electrode 1, the recording surface 6' of the recording paper 6
has almost the same potential as the control electrode 5. An electric charge is given to the ridge 4-1 of the magnetic fluid from the recording electrode 1, and an electrostatic attraction is exerted between it and the recording surface 6' of the recording paper 6, and the magnetic fluid 4 is drawn from the tip of the ridge 4-1. The droplets fly onto the recording surface 6' of the recording paper 6, and one predetermined printing is performed. The recording paper 6 moves a predetermined distance each time one printing is completed, and high voltages are sequentially applied to sequentially print. However, in reality, as shown in FIG.
At the same time that the control electrode 5 is formed, the magnetic fluid 4-2 is attached to the end surface A of the base 2 due to sagging of the magnetic fluid, etc., as shown in FIG. When a voltage is applied between and the recording electrode 1,
Not only is the charge applied from the recording electrode 1 to the protrusion 4-1 of the magnetic fluid, but also the charge is applied to the magnetic fluid 4-2 attached to the portion A of the base 2 by induction. At this time, the protrusion of the magnetic fluid 4-1
Electrostatic attraction acts on the magnetic fluid 4 from the bump 4-1.
It goes without saying that the magnetic fluid flies in the form of droplets toward the recording paper 6 and prints are obtained, but at the same time, from the magnetic fluid 4-2 attached to the end surface A of the base 2, The magnetic fluid 4 turns into droplets and flies towards the recording paper 6, causing noise. This flying noise often occurs periodically, and is usually a noise on the print that degrades the print quality, but in severe cases, it occurs constantly and appears on the recording paper 6. In some cases, the print is completely smeared and the printed image cannot be recognized at all.

As explained above, with conventional devices, it is difficult to obtain stable, high-quality printing, which has been a major problem.

The present invention eliminates such drawbacks and provides a magnetic fluid recording device that can stably obtain high-quality printed images.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

FIG. 3 shows a schematic configuration of a magnetic fluid recording device which is an embodiment of the present invention. A recording electrode 1 is mounted on the base 2, and a bump magnet 3 is mounted on the recording electrode 1. The recording electrode 1 is magnetized by a bump magnet 3, and a magnetic fluid bump 4-1 is formed near the tip of the recording electrode 1 in the same way as in the conventional one.
A control electrode 5 is placed facing the recording electrode 1 at a predetermined distance, and a recording paper 6 is placed in contact with the control electrode 5. A high voltage power supply 7 is connected between the recording electrode 1 and the control electrode 5, and a power supply ON/OFF switch is provided between the recording electrode 1 and the control electrode 5.
A predetermined high voltage is applied for a predetermined time by a voltage drive circuit 8 that performs control.
The end face of the base 2 near the tip of the recording electrode is cut at an acute angle of about 30° to 60°, and the acute-angled face B of the base 2 has a magnetic fluid collecting material made of a fibrous material or a porous material. Member 9 is attached. A recovery tank 10 is installed below the magnetic fluid recovery member 9. Further, the tip of the base 2 is configured to extend from the tip of the uplifting magnet 3 to the tip of the recording electrode 1 on the tip side of the recording electrode 1, thereby reinforcing the recording electrode 1.

Next, the operation of this device will be explained.

As shown in FIG. 3, the magnetic fluid 4 tries to adhere to the acute-angled surface B at the tip of the base 2, but the fourth
As shown in the figure, the magnetic fluid adhering to the acute-angled surface B is transferred to a magnetic fluid collection member 9 made of a fibrous material or a porous material attached to the acute-angled surface B.
It is quickly absorbed by capillary action, passes through the magnetic fluid collection member 9, and drips into the tank 10.
It will be collected. Therefore, the magnetic fluid 4 hardly adheres to the acute-angled surface B at the tip of the base 2, and even if it does adhere to a very small amount due to wettability, the tip of the base 2 The acute angle surface B is far away from the control electrode 5 and the recording paper 6 by the amount of the acute angle, and therefore, the distance between the control electrode 5 and the recording electrode 1 is large.
Even if a high voltage is applied between them and a charge is given by induction to the magnetic fluid 4-2 slightly attached to the acute-angled surface B, the magnetic fluid 4-2 slightly attached to the acute-angled surface B is charged by induction, but the magnetic fluid 4-2 slightly adheres to the acute-angled surface B. , the electrostatic attraction acting on the magnetic fluid 4-2 slightly attached to the acute-angled surface B is weak, and the magnetic fluid 4-2 does not become a droplet and fly. Therefore, the magnetic fluid 4 flies only from the protuberances 4-1 of the magnetic fluid 4, and therefore, a predetermined print can be obtained without noise or print stains.

Next, another embodiment of the present invention will be described using FIG. FIG. 5 shows another embodiment of the present invention, in which the magnetic fluid collecting member 9' is constituted by a magnet. Therefore, the magnetic fluid 4 adhering to the acute-angled surface B is quickly absorbed by the magnetic force of the magnetic fluid collection member 9', which is a magnet, and is further dropped into the tank 10 and collected. Therefore, in this embodiment as well, effects similar to those of the embodiment shown in FIGS. 3 and 4 can be obtained, and good printing without noise or printing stains can be obtained.

As described above, according to the present invention, it is possible to greatly reduce flying noise and perform stable and high-quality printing. In addition, the tip of the base can be extended almost to the tip of the recording electrode, thereby reinforcing the recording electrode and improving the pitch accuracy in the arrangement direction of the recording electrode. Additionally, by reinforcing the recording electrode, it is possible to increase the mechanical strength of the recording electrode, improve ease of handling during the production process, and improve reliability.

[Brief explanation of the drawing]

1 and 2 are block diagrams of a conventional magnetic fluid recording device, FIGS. 3 and 4 are block diagrams of a magnetic fluid recording device that is an embodiment of the present invention, and FIG. 5 is a block diagram of a magnetic fluid recording device according to the present invention. It is a block diagram which shows another Example of. 1...Recording electrode, 2...Base, 3...Elevation magnet, 4...Magnetic fluid, 4-1...Elevation of magnetic fluid, 4-2...Excess attached to the tip of the base Magnetic fluid, 5... Control electrode, 6... Recording paper, 6'...
... recording paper surface, 7 ... high voltage power supply, 8 ... high voltage power supply drive circuit, 9 ... magnetic fluid collection member made of fibrous material or porous material, 10 ... tank.

Claims (1)

[Claims] 1. A single or plural recording electrodes provided on a recording surface, a non-magnetic base supporting the recording electrodes,
a protruding magnet for magnetizing the recording electrode and protruding the magnetic fluid on the recording electrode on a side opposite to the recording electrode, and extending the tip of the base approximately to the tip of the recording electrode; 1. A magnetic fluid recording device characterized in that the recording electrode has an end face on a tip side facing downwardly at an acute angle with respect to a surface that holds the recording electrode. 2. The magnetic fluid recording device according to claim 1, wherein the acute angle formed between the end face on the tip side of the recording electrode and the surface holding the recording electrode is 30° to 60°.