JPS58217375A - Magnetic ink recording device - Google Patents

Abstract

PURPOSE:To obtain the titled device, by which swelling shapes of ink are made uniform and the noise flying of the ink is prevented, and wherein multistyluses arranged at both end parts are arranged at the positions which are made to recede from multistyluses at the cetral part among the entire multistyluses. CONSTITUTION:The corner part of each auxiliary magnetic pole piece 23 is bevelled. The pole pieces are provided at both end parts of a line of styluse electrodes 21 so that the pole pieces are aligned with the aligned line of the tips of the arranged styluse electrodes 21 or the pole pieces are made to recede from the line slightly. The distance (a) between the pole piece and the stylus located at the end is made to be about 70-80mum. A swelled magnet 22 is intimately contacted with the upper sides of the stylus electrodes 21 and the auxiliary magnetic pole pieces 23. Since ink 24 is attached to the auxiliary magnetic pole pieces 23, the radius of the tip of the ink 24 at the stylus electrodes 21 at both ends becomes the same as the radius of the tip of the ink 24 at a central part (f). The radius of the tip of the ink 24 attached to the auxiliary magnetic pole pieces 23 becomes larger than that at the central part (f). Therefore noise flying is hard to occur.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic ink recording device, and an object of the present invention is to make the shape of the protuberances of ink adhering to a print head uniform and to prevent the noise of the ink from flying.

A conventional magnetic ink recording device will be explained with reference to FIGS. 1 and 2. A large number of needle-shaped stylus electrodes 2 made of magnetic material are adhered to an insulating base 1 to form a multi-layered stylus electrode 2, and a raised magnet 3 for magnetizing the stylus electrode 2 is tightly attached near the tip of the stylus electrode 2. constitutes the print head. Magnetic ink 4 is placed in a tank 6, and a supply magnet 6
is supplied to the print head by. The supplied magnetic ink 4 also adheres to the tip of the magnetized stylus electrode 2.

The amount of ink deposited is determined by the head difference (H) between the tip of the stylus electrode and the ink level in the ink tank 5. 7 is the @ group, and the control electrode 8 is arranged behind it. A drive roller 9 transports the recording paper 7 in the direction of arrow C by a drive source (not shown). 10 is a DC power supply, and 11 is a drive circuit that selectively supplies electricity to the stylus electrode 2. 12
is a control circuit that switches the voltage of the counter electrode 8.

When voltage is applied to the stylus electrode 2, the magnetic ink 4 attached to the tip of the stylus electrode 2 to which the voltage has been applied flies toward the counter electrode 8, and the ink 4 is attached to the recording plate 7 to perform printing. . Figure 2 is an enlarged view of the left end of the print head in Figure 1 when viewed from direction D, ink 4.
The characteristics of the ink flying from the tip of the stylus electrode 2, as shown in FIG. 2, depend on the radius of curvature (R) of the convex and convex portions of the ink 4 adhered to the stylus electrode 2. Radius of curvature (R
) is large, the voltage required for flight increases, and the radius of curvature (
If R) is small, the voltage required for flight will be low. In a structure in which stylus electrodes 2 with a diameter of 50 μm are arranged at a pitch of 125 μm so that the linear density is 8 dot/g,
The radius of curvature is set to about 40 μm, the bias voltage of the power source 1o is set to about 5ooV, the drive circuit 11 selectively applies a voltage of 400V to the stylus electrode 2, and the control circuit 1
2, switch the potential 500V of the control electrode 8,
A good image was obtained when a total voltage of 1700V was applied. However, the radius of curvature of the stylus electrode 20 is the radius of curvature R1 of the ink 4 of the central stylus electrode 2.
On the other hand, the radius of curvature R2 of the stylus electrode 2 portion at the end is R1>R2.

This is because "the tip radius of the stylus electrode 2 at the end becomes small because when the ink 4 is attached as shown in FIG. This is because the stylus electrode 2 at the end is attracted to the raised magnet 3 side, and the amount of ink 4 adhering to the stylus electrode 2 at the end tends to decrease, and the radius of the tip becomes smaller. The voltage decreases, and when the stylus electrode 2 is not selectively energized, the bias voltage alone has the disadvantage that noise tends to fly from the stylus electrode 2 at the end.

The present invention eliminates such drawbacks, and provides a recording device with good print quality by eliminating unevenness in the shape of the protrusions at both ends of the multi-layered stylus electrode 20 and preventing flying noise. It is. A magnetic ink recording apparatus which is an embodiment of the present invention will be described below with reference to FIGS. 3 to 6.

FIG. 3 is a partial perspective view of a print head of a magnetic ink recording device according to an embodiment of the present invention. In the figure, 20 is a base made of an insulator, 21 is a stylus electrode, and a large number of them are bonded to the base 20. A groove having a depth of about 100 μm is formed between the stylus electrodes 21 of the base body 2o. The stylus electrode 21 has a diameter of 50 μm (7) F e −N
They are arranged at a pitch of 125 μm on the i-line. FIG. 4 is a front view of the print head section, and FIG. 5 is a view taken in the direction of arrow E in FIG. 22
23 is a raised magnet, and 23 is an auxiliary magnetic pole piece made of Fe-Ni alloy with a thickness of 5,071 m, a width of 2001 parts, and a length of 2 m.
, the corners are chamfered to prevent the concentration of magnetic flux lines,
The stylus electrode 21 is attached to both ends of the stylus electrode 21.
It is provided at the same position or slightly backward from the array tip line, and the distance a from the end to the stylus is approximately 70 to 80 μm. The raised magnet 22 is in close contact with the stylus electrode 21 and the auxiliary pole piece 23.

24 is magnetic ink, and 26 is a supply magnet for supplying ink. When the magnetic ink 24 is attached to the print head with the above configuration, since the auxiliary magnetic pole pieces 23 are located outside of the stylus electrodes 21 at both ends, the ink 24 adheres to the auxiliary magnetic pole pieces 23. The tip radius R of the ink 24 of No. 1 is the same as the tip radius of the ink 24 of the central portion f. Furthermore, the radius of the tip of the ink 24 adhering to the auxiliary pole piece 23 becomes even larger than that of the central portion f, making it extremely difficult for the ink 24 to fly. Therefore, even if the induced voltage of the bias voltage is induced in the auxiliary pole piece 23, no noise will fly. As described above, in this embodiment, with a simple configuration, the protrusions of the stylus electrodes 21 at both ends can be made uniform, and high-quality printing without flying noise can be performed.

Next, another embodiment of the present invention will be described with reference to FIGS. 6 to 8.

FIGS. 6 and 7 are explanatory diagrams of the operation of a print head of a magnetic ink recording apparatus according to another embodiment of the present invention.

'FIG. 6 is a plan view of the end of the head, and FIG. 7 is a front view of the head. Although the d part is the regular stylus electrode 21,
Part 0 (on both sides of the head) is provided with a plurality of gummy histyl rice 30. The distance between the dummy styli 30 is such that there is no groove between the regular stylus electrodes 21, and between the dummy styli 30 there is a non-magnetic resin 3.
1 is filled so that it is flush with the stylus.

When the magnetic ink 24 is attached to the tip of the stylus 30 with the above configuration, since no groove is formed between the dummy styli 30, the ink does not dent in the groove, so the radius of curvature of the ink 24 on the dummy stylus 30 is prevented. R becomes larger. Therefore, a protrusion with a normal radius of curvature occurs in the regular stylus portion d, but since the radius of curvature is large in the dummy stylus portion C, no flying noise occurs.

FIG. 8 shows a top view of the end of a head according to another embodiment of the present invention. Part d is a regular stylus, and part 0 is a dummy stylus 4o made of the same material as the plurality of regular styluses, which are provided at both ends of the head. dummy stylus 40
The distance (2) between the tip of the stylus and the tip of the raised magnet 22 is the shortest at the end of the stylus, and gradually becomes approximately the same as the regular stylus electrode 21 as it approaches the regular stylus electrode 21. Therefore, dummy brace 1. Even if the magnetic ink 24 is attached to the dummy stylus 40, the ink attached to the dummy stylus 4o will cause the convex part of the ink protrusion of one stylus part and the concave part of the ink protuberance of the adjacent stylus part to be at the same height. Due to surface tension, the unevenness is smoothed out, and the unevenness of the ink becomes very small, and the ink is washed away. On the other hand, the stylus electrode 21 at the end of the regular stylus portion d has the same protrusion as the other regular stylus electrodes 21 because the dummy stylus 40 is located outside of it. Therefore, no noise is generated from the stylus electrode 21 at the end.

As described above, according to the present invention, flying noise can be prevented with a simple configuration.

[Brief explanation of drawings]

Figure 1 is a side sectional view of a conventional magnetic ink recording device, Figure 2 (a) is a front view of the same print head, Figure 2 (a) is a plan view of the same, and Figure 3 is an embodiment of the present invention. FIG. 4 is a front view of the print head of a certain magnetic ink recording device, FIG. 5 is an enlarged view taken in the direction of arrow E in FIG. 4, and FIG. 6 is an end of another print head of the present invention. Fig. 7 is a front view of the same, Fig. 8 is a plan view of the section.
The figure is a front view of the end of a print head according to another embodiment of the present invention. 2o... Base body, 21... Stylus,
22... Raised magnet, 24... Auxiliary pole piece, 26... Supply magnet. Name of agent: Patent attorney Toshio Nakao and one other person
Figure 31 Figure 2171 Figure 3 Figure 4 E ↓ 5 450 Figure 6 5 Figure 8 Δj

Claims (2)

[Claims] (1) A multi-stylus made of a magnetic material, and a protrusion magnet that contacts near the tip of the multi-stylus, extends in the multi-stylus arrangement direction, and magnetizes the multi-stylus, and has magnetic ink at the tip of the stylus. A magnetic ink recording head that opposes the multi-stylus via a recording surface, a control voltage applied to the multi-stylus and the control electrode in accordance with an image signal, and a Coulomb force from the magnetic ink recording head. It is characterized by comprising a voltage applying means for performing recording by flying magnetic ink onto the recording surface, and of the multi-stylus, the multi-styli arranged at both end portions are set back from the multi-stylus in the center. A magnetic ink recording device. (2) The magnetic ink recording device according to claim 1, wherein the multi-styli arranged at both end portions are strip-shaped thin plates.