JPH0596737A - Ink jet printer - Google Patents

Abstract

PURPOSE:To constitute a downsized device or serial printer which can print with a low applying voltage by feeding a coil with current thereby magnetizing magnetic fluid ink at the opening of a nozzle and then flying an ink droplet with attractive force produced with respect to a platen. CONSTITUTION:When a pulse current is fed to a coil 3 disposed on the periphery of the nozzle opening 2 of an ink jet head 1, magnetic fluid ink 4a filled in the nozzle opening 2 is magnetized thus imparting magnetism to an ink meniscus at the tip thereof. Since the surface of a platen 7 is magnetized with opposite polarity to that of the ink meniscus 19 at that time, attracting force functions between the surface of the platen 7 and the ink meniscus 19 to produce an ink droplet which flies toward the platen 7. When a recording paper 8 is placed between the ink jet head 1 and the platen 7, the flying ink droplet 9 adheres to the recording paper 8 thus effecting printing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer for printing on recording paper by ejecting ink.

[0002]

2. Description of the Related Art FIG. 4 is a plan view showing an example of a recording head of a conventional ink jet printer.

A conventional recording head of an ink jet printer which prints on recording paper by ejecting ink is
As shown in FIG. 4, the magnetic fluid ink 12 is placed in the ink tank 13 mounted on the magnetic material substrate 16, and is stably held by the electromagnet 14, and the magnetic material of the permanent magnet 15 causes The thin rod is pulled up above the recording needle 10 bent in an “L” shape, and a voltage is applied between the recording needle 10 and the control electrode 11 provided above the recording needle 10, whereby an ink droplet is ejected from the control electrode 11. Printing is performed by causing the recording paper 18 wound around the recording paper 18 to be attached to the recording paper 18 wound around the drum 17.

[0004]

The conventional ink jet head as described above requires a high voltage for ejecting ink droplets, and cannot print the print head in the direction of the spacing. The system is limited to the drum system, and there is a drawback that the device becomes large.

[0005]

An ink jet printer of the present invention comprises an ink filling section for filling the magnetic fluid ink therein, a nozzle section for ejecting the magnetic fluid ink, and a magnetizing section provided around the nozzle section. It has a recording head and a platen whose surface is at least made of a magnetic material.

[0006]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a plan view showing a recording head of a first embodiment of the present invention, and FIG. 2 is a plan view showing a printing mechanism section including a sectional view taken along the line AA of the recording head of FIG.

A recording head (inkjet head) 1 shown in FIGS. 1 and 2 has a nozzle plate 5 made of a magnetic material and a sub ink tank 6 made of a non-magnetic material.
And a coil 3 provided around the nozzle opening 2 of the nozzle plate 5, and in the ink flow path 4 of the sub ink tank 6, the magnetic fluid ink 4a supplied from an ink tank (not shown) is provided. Is filled. A platen 7 is arranged so as to face the nozzle opening 2, and the surface of the platen 7 is covered with a magnetic material.

The ink jet printer constructed as described above operates as follows. That is, the coil 3 provided around the nozzle opening 2 of the inkjet head 1
When a pulse current is supplied to the magnetic fluid ink 4a filled in the nozzle opening 2, the ink meniscus 19 at the tip of the magnetic fluid ink 4a becomes magnetized. At this time, since the surface of the platen 7 whose surface is covered with a magnetic material is magnetized to have a polarity opposite to the magnetism of the ink meniscus 19, an attractive force acts between the surface of the platen 7 and the ink meniscus 19, The ink meniscus 19 becomes an ink droplet and flies toward the platen 7 (arrow B). By interposing the recording paper 8 between the inkjet head 1 and the platen 7, the flying ink droplets 9 can be attached to the recording paper 8 for printing. The ink meniscus 19 at the tip of the nozzle opening 2 after the ink droplet 9 flies is restored to its original state because the magnetic fluid ink 4a rises due to the capillary phenomenon.

In the above embodiment, only the surface of the platen is made of magnetic material, but the entire platen may be made of magnetic material. Alternatively, the entire platen may be formed of a permanent magnet.

FIG. 3 is a plan view showing a recording head of a second embodiment in which the present invention is applied to an ink jet printer having a multi-nozzle type recording head.

The embodiment of FIG. 3 is an example in which the present invention is applied to an inkjet printer having a multi-nozzle type inkjet head.
In the above, a plurality of nozzle openings 22 are arranged in a horizontal row, and a coil 23 is provided in each nozzle opening 22. The operation and action of this embodiment are the same as those of the embodiment of FIG. With this configuration, the sub ink tank is partitioned, and not only black ink but also ink of each color such as yellow, magenta, and cyan is supplied, so that color printing can be performed.

[0013]

As described above, in the ink jet printer of the present invention, the nozzle opening is provided in the sub ink tank filled with the magnetic fluid ink, and the coil is arranged around the nozzle opening. The surface or the whole of the platen facing the nozzle opening is made of a magnetic material, and an electric current is passed through the coil to magnetize the magnetic fluid ink in the nozzle opening and to generate an attractive force between the platen and the magnetic fluid ink. By flying the ink droplets, it is possible to perform printing with a small applied voltage, and it is possible to configure a small device or a serial printer.

[Brief description of drawings]

FIG. 1 is a plan view showing a recording head according to a first embodiment of the invention.

FIG. 2 is a plan view showing a printing mechanism section including a sectional view taken along the line AA of the recording head of FIG.

FIG. 3 is a plan view showing a recording head of a second embodiment in which the present invention is applied to an inkjet printer including a multi-nozzle type recording head head.

FIG. 4 is a plan view showing an example of a recording head of a conventional inkjet printer.

[Explanation of symbols]

 1 inkjet head 2 nozzle opening 3 coil 4 ink flow path 4a magnetic fluid ink 5 nozzle plate 6 sub ink tank 7 platen 8 recording paper 9 ink droplet 10 recording needle 11 control electrode 12 magnetic fluid ink 13 ink tank 14 electromagnet 15 permanent magnet 16 Magnetic Material Substrate 17 Drum 18 Recording Paper 19 Ink Meniscus 21 Inkjet Head 22 Nozzle Opening 23 Coil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuya Hiraga 1 Kagarai, Ichinoseki, Iwate Prefecture Tohoku NEC Corporation

Claims (3)

[Claims] 1. A recording head having an ink filling section filled with magnetic fluid ink, a nozzle section for ejecting the magnetic fluid ink, and a magnetized section provided around the nozzle section, and a magnetic material having at least a surface. An ink jet printer, comprising: a platen formed of. 2. The ink jet printer according to claim 1, further comprising a platen which is entirely made of a magnetic material. 3. The ink jet printer according to claim 1, further comprising a platen which is entirely formed of a permanent magnet.