JPS58136456A - Magnetic ink recorder - Google Patents

Abstract

PURPOSE:To improve the selectivity of image signals by making ink flying to record as an ink swell is formed only at the tip of a needle electrode corresponding to the position intended to record with a spiral magnet turning at a fixed speed with a roll. CONSTITUTION:As a roll 14 is turned at a fixed speed when recording, a spiral magnet 15 facing a needle electrode 1 at the closest position moves at a fixed speed and magnetizes the needle electrode gradually. Ink 4 at the tip thereof swells gradually and moves with the rotation of the roll 14. In this case, the formation of the ink swell is confined to the needle electrode 1 at the opposed position thereto, for example, the position 19, none at other positions. Here, a negative pulse voltage 10 of the image signal is applied to an opposed electrode 13 synchronizing the formation of the swell at the tip of the needle electrode 1 at the position intended to record to make a swelling ink 4 flying onto a recording paper 5 for recording. At this position, there is no ink swell at any tip of other needle electrodes 1 thereby improving the selectivity of image signals, namely, S/N ratio with little ink flying.

Description

[Detailed description of the invention] The present invention relates to a magnetic ink recording device.

Conventionally, in inkjet recording methods, such magnetic fluid (hereinafter simply referred to as ink) is used as ink, the ink is attached to the tip of a needle electrode magnetized by a magnet to form a bump, and an electric field or an electric field is applied in response to an image signal. A method has already been proposed in which recording is performed by applying a magnetic field to cause ink to be ejected onto recording paper from a single needle electrode or multiple needle electrodes.

Here, the magnetic fluid is a colloidal solution of magnetic fine particles and a liquid dispersion medium. Specifically, magnetite (Fo30
It is a liquid in which fine particles such as 4) (particle size: 100 p, -) are suspended in a dispersion medium together with a surfactant.

Dispersion media for this magnetic fluid include paraffin, water, ester oil, silicone oil, etc., and surfactants and
- In addition to oleic acid and linoleic carboxylic acids,
Cationic activators and nonionic activators are used.

Regarding magnetism, it is said to exhibit superparamagnetism, and is a magnetic material that does not have magnetic hysteresis.

A conventional magnetic ink recording apparatus will be explained below with reference to FIGS. 1 to 7.

FIG. 1 is a schematic diagram of a conventional magnetic ink recording apparatus.

In the figure, reference numeral 1 denotes magnetic recording needle electrodes, which are arranged at equal intervals on a base 2 made of an insulating and non-magnetic material and are glued. 3
is a raised magnet attached near the tip of the needle electrode 1, and its shape and attachment position are selected appropriately to magnetize the needle electrode 1 and have the role of attaching ink 4 to the tip to form a bump. have.

The amount of ink adhering to the tip of the needle electrode 1 is controlled so that the amount of ink adhering to the raised magnet 3 is 1tl-8! It is done by controlling.

Ink 4 is supplied to the raised magnet 3 by an ink supply means (not shown), and the amount of ink adhering to the raised magnet 3 is controlled to be appropriate.

6 is a recording paper, which is placed at a predetermined distance (1o) from the needle electrode 1.

~600 μm), and is moved in the direction of arrow 7 as recording progresses along a counter electrode 6 that also serves as a guide.

A bias voltage (D,
C) 8 is added at various polarities in the figure.

For recording, a positive pulse voltage 9 of a scanning signal is sequentially applied to the needle electrode 1.
- A negative pulse voltage 10 of an image signal is applied to the blade counter electrode 6. The ink 4 is ejected by the Coulomb force of the electric field, and recording is performed using a matrix scanning method.

Figure 2 shows the state of ink adhesion at the tip of the needle electrode 1 shown in Figure 1.
is the same plan view.

In Fig. 2, since the needle electrode 1 is magnetized by the raised magnet 3, the magnetic field becomes stronger than the space between adjacent needle electrodes 1, so that the tip of the needle electrode 1 becomes a mountain and a needle as shown in the figure. The ink 4 adheres so that valleys are formed between the electrodes 1. Figure 2 shows
The bumps caused by the adhesion of the ink 4 have an appropriate shape. ◎ Figures 3 and 4 are examples of cases where the bumps of the ink 4 are not appropriate. Figure 3 shows the amount of ink adhering to the raised magnet 3. FIG. 4 shows the case of too much, and FIG. 4 shows the case of too little. FIG. 6 is a layout diagram showing the positional relationship between the needle electrode 1 and the counter electrode 6. As shown,
A plurality of needle electrodes 1 are connected to one counter electrode 6.

The magnetic ink recording device described above does not use nozzles, so it does not have the disadvantages of the nozzle method (high speed, high density, However, in this magnetic ink recording device, the ink ridges of the needle electrodes 1 are always connected to each other between the needle electrodes 1.
Depending on the conditions of the electric field applied between the needle electrode 1 and the counter electrode 6, the raised state can easily become as shown in Fig. There was a problem.

Furthermore, since the protuberances are always formed in approximately the same shape and size, and since the needle electrode 1 and the counter electrode 6 are in the positional relationship as shown in FIG. 6, an image signal is applied to the counter electrode 6. When this happens, there is also a problem in that the ink 4 also flies from the needle electrode 1 at a position where it should not be recorded, resulting in recording noise.

Next, FIG. 6 shows another conventional magnetic ink recording device.

This will be explained using FIG.

FIG. 6 is a schematic configuration diagram of the apparatus, and FIG. 7 is an enlarged perspective view of the leading end of the recording section of the apparatus.

This device is basically the same as the above-mentioned device explained in FIGS. 1 to 6 in terms of recording principles, etc.
The same numbers as those in FIG. 1 also have the same functions, so detailed explanations will be omitted.

The difference between this device and the device shown in FIG. 1 is that the needle electrode 1 is disposed in an ink groove 12 formed on a base 2;
The point is that the raised magnet 11 that magnetizes the needle electrode 1 is not brought into direct contact with the needle electrode 1.

Therefore, in this device, as shown in FIG.
The ink ridges at the tips of are independent of each other and do not connect with adjacent ridges.

Therefore, problems such as the ink 4 flying from between the needle electrodes 1 do not occur.

However, by always forming protuberances of the same shape and size,
With the positional relationship between the needle electrode 1 and the counter electrode 6 as shown in FIG.
Since a scanning signal is sequentially applied to the needle electrode 1 and an image signal is applied to the counter electrode 6, there is no problem that when the image signal is applied to the counter electrode 6, the ink 4 flies even from the needle electrode 1 which should not be used for recording. , which is not solved by this device.

The present invention solves the problems described above, and the ink bulges at the tip of the needle electrode at the position where recording should be made are different from the ink bulges at the tip of the needle electrode at positions where recording should not be made. By increasing the size, it is possible to provide a magnetic ink recording device with good selectivity (S/N) of ink protrusions with respect to image signals.

An embodiment of the present invention will be described below with reference to FIGS. 8 and 9.

FIG. 8 is a schematic configuration diagram of a magnetic ink recording device according to an embodiment of the present invention, and FIG. 9 is an explanatory diagram of the operation of the same device.

The needle electrode 1 is disposed at the bottom of a plurality of ink grooves 12 provided at equal intervals on a base (insulator, non-magnetic material) 2. The ink groove 12 supplies the ink 4 to the tip of the needle electrode 1 by its capillary force. Ink is supplied to the ink groove 12 by another supply means (not shown).

The recording paper 6 is located at a predetermined position from the tip of the needle electrode 1, and is moved in the direction of the arrow 7 along the opposing electrode 13, which also serves as a guide, as recording progresses. Note that the counter electrode 13 consists of one electrode that is placed opposite to all the needle electrodes 1.
A bias voltage (D-C) a is applied between the
is always added.

A roll 14 is rotatable around a shaft 17 made of a non-magnetic material, and rod-shaped magnets 16 are attached to the surface of the roll in a spiral manner.

The magnet 16 is a raised magnet that magnetizes the needle electrodes 1, and is designed so that as the roll 14 rotates, the needle electrodes 1 are sequentially magnetized in the direction in which they are arranged.

The magnet 16 is wound around the surface of the roll 14 in a single thread, using the same expression as in the case of a screw. That is, by rotating the roll 14 once, the magnets 15 facing the needle electrodes move from one end of the array of the needle electrodes 1 to the other.

The size and strength of the magnet 16 are selected so as to be sufficient to magnetize one needle electrode 1.sup.1 facing each other, but are selected so that the needle electrodes 1 and 2 cannot be sufficiently magnetized.

Note that the roll 140 rotations are performed by a motor (not shown).

The operation during recording will be explained below.

When recording, the roll 14 is rotated at a constant speed in the direction of the arrow 16. Then, the magnet 16 facing the needle electrode 1 at a position closest to it moves at a constant speed in the direction of the arrow 18 in FIG. Accordingly, the needle electrode 1 is sequentially magnetized in the direction of the arrow 18, and as a result, the ink 4 at the tip of the needle electrode 1 is also sequentially raised.

In other words, as the roll 14 rotates, the ink bulge becomes
It will move in 8 directions.

FIG. 9 shows that an ink bulge is formed at the tip of the needle electrode 1 at position 19. At this time, at the tip of the other needle electrode 1, slight ink ridges are formed on both sides of position 19, but no ridges are formed in other parts.

The negative pulse voltage 1o of the image signal is applied to the needle electrode 1 at the position to be recorded.
The voltage is applied to the counter electrode 13 in synchronization with the formation of an ink bump at the tip. Then, the needle electrode 1 at the position to be recorded
The ink 4 is ejected onto the recording paper 5 to perform recording.

At this time, there is no ink bulge at the tip of the needle electrode 1 other than the position to be recorded, and even if there is, it is small and the shape is insufficient, so the ink 4 may fly from these needle electrodes 1. In addition, as mentioned above, it goes without saying that the magnets 15 may be arranged in n stripes on the roll 14, and in this way, ink ridges can be formed on each of the n needle electrodes 1. By configuring the counter electrode 13 as shown in FIG. 5, matrix scanning can be performed and the recording speed can be improved.

In this embodiment, the needle electrode 1 is disposed within the ink groove 12,
An example of a configuration in which the needle electrodes 1 are magnetized by a magnet 15 separated from the needle electrodes 1 has been shown, but the present invention is not limited to this. It goes without saying that a configuration in which the magnets 16 are separated from each other and magnetized, that is, a configuration in which the ink bulges at the tips of the needle electrodes 1 are connected to each other between the needle electrodes 1 is also effective.

As explained above, according to the present invention, an ink bulge is formed only at the tip of the needle electrode at a position to be recorded, and recording is performed by flying the ink from there. There is almost no noise from the ink flying from the needle electrode, and recording with extremely good image signal selectivity (S/N) can be obtained.

In addition, since there is no need to apply sequential scanning signals to the needle electrode, there is no need for a driver to apply and control sequential scanning signals to the needle electrode, resulting in a significant cost reduction and a low-cost recording device. can get.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a conventional magnetic ink recording device, Figs. 2 to 4 are explanatory diagrams of the state of ink adhesion at the tip of the recording section of the device, and Fig. 5 is a needle electrode and a counter electrode of the device. 6 is a schematic configuration diagram of another conventional magnetic ink recording device, FIG. 7 is a partial perspective view of the tip of the recording section of the same device, and FIG. 8 is an embodiment of the present invention. FIG. 9 is a schematic block diagram of a magnetic ink recording apparatus, and FIG. 9 is an explanatory diagram of the operation of the apparatus. 1・φ・・−e needle electrode, 2・・■・・base, 3, 11.
15...Magnet, 4...Ink, 6...
... Recording paper, 6.13 ... Counter electrode, 7,
18...arrow, 8---bias voltage,
9-----Positive pulse voltage, 10...Poss...Negative Hals tE pressure, 12-...L14...Name of Roll agent Patent attorney Toshio Nakao and one other person ll
Figure 4i Figure 2 5 1 Il (mouth 1 Figure 3 4 c)) (a) Figure 4 U) μ no 15 Figure θ 16 Figure 18 Figure 1 θ Figure 9 5

Claims (1)

[Scope of Claims] (1) A plurality of needle electrodes made of a magnetic material arranged at approximately equal intervals, magnetizing means for selectively magnetizing one or more of the needle electrodes, and a magnetization means for selectively magnetizing one or more of the needle electrodes; , a supply means for supplying magnetic ink, one or more counter electrodes opposed to the needle electrode in front of the needle electrode, and a supply means corresponding to an image signal between the needle electrode and the counter electrode. A magnetic ink recording device characterized by comprising a voltage applying means for applying a voltage. (2) The magnetizing means is a spiral magnet provided on the outer periphery of the rotating roller. The magnetic ink recording device according to item 1. (3) Needle electrodes are formed at equal intervals on the surface of the base made of non-magnetic and insulating material, and extend at least to the vicinity of the tips at the bottoms of multiple ink grooves with their tips facing the end surface of the base. 2. The magnetic ink recording device according to claim 1, wherein the magnetic ink recording device is arranged so that the ink groove is a supplying means.