JPS6038175A - Magnetic ink supply method of dot printer - Google Patents

Abstract

PURPOSE:To make the supply of magnetic ink to a slit constant, by supplying magnetic ink to the slit between a pair of magnetic poles, through which the leading ends of needles arranged in a line form are protruded and retracted, from the upper part thereof, and falling the magnetic ink after use by eliminating the magnetic field between the magnetic poles. CONSTITUTION:The leading ends of plural needles 10 driven by a electromagnet are arranged in a line form while a pair of magnetic poles 14, 14 are provided so as to leave a slit 13 through which said needles can be protruded and retracted and magnetically coupled with both magnetic poles of an electromagnetic coil 11. A hermetically closed type ink tank 17 for storing magnetic ink is provided to the upper part of the slit 13 and an orifice 19 having a size preventing the dripping of the magnetic ink under its own wt. is provided to the lower part of said ink tank and the magnetic ink is sucked into the slit 13 by the magnetic field between the magnetic poles 14, 14 to form an ink film. After printing is finished, current supply to the electromagnetic coil 11 is stopped to fall the magnetic ink in the slit under its own wt.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a magnetic ink supply method for a dot printer.

Technical background of the invention and its problems Conventional dot printers impact pressure-sensitive paper with a needle along a platen, or impact plain paper with the needle through an ink ribbon, and the impact noise is loud.

For this reason, a pair of magnetic poles are placed facing each other at the tip of the print head, and the lower end of the slit between these magnetic poles is connected to all the ink tanks, and the magnetic field between the AL poles attracts the magnetic ink to all the slits in the ink tank. There is a method in which a film is formed and a needle is passed through the film and magnetic ink is transferred from the tip of the needle to recording paper.

However, in this type of product, after use, the magnetic ink in the slit, which has a large contact area with the outside air, is returned to the ink tank at the bottom, and the ink tank is communicated with the slit, so that when not in use, the magnetic ink is released over the entire liquid surface. Due to the pressure applied, the solvent of the magnetic ink will not evaporate, therefore,
If the density of the magnetic ink is not high, the area that the magnetic ink touches becomes magnetic.

It has the disadvantage that solidified ink scum tends to accumulate. Further, in the case where an ink tank is provided below the slit, the level of magnetic ink inside gradually decreases, so the level of magnetic ink in the slit also decreases. In order to compensate for this, it is necessary to add another ink tank to replenish the magnetic ink to the lower ink tank.Purpose of the InventionThis invention was made in view of the above points, and it is possible to reduce the concentration of the magnetic ink by changing the density of the magnetic ink. The purpose of this invention is to develop a magnetic ink supply method for a dot printer that can reduce the amount of magnetic ink supplied to the slit and maintain the supply of magnetic ink to the slit at a certain level.

Summary of the Invention In this invention, a magnetic ink tank attracts ink to a slit between opposing magnetic poles, and a needle passes through the magnetic ink film of the slit completely to transfer the magnetic ink to recording paper, but the magnetic ink is supplied from the top of the slit. By doing so, the entire area to which external pressure is applied to the magnetic ink inside the ink tank is significantly reduced, and after use, the magnetic field between the magnetic poles is removed and the magnetic ink between the magnetic poles is directed downward, thus being supplied to the slit. Changes in the density of the magnetic ink are extremely small to make the print density uniform, and even though the magnetic ink is consumed over time, it is supplied from the top of the slit, so regardless of the amount of ink consumed, a portion of the ink can be used! A constant level of magnetic ink can be supplied to the slit, thus
It is constructed so that an ink tank for replenishment is omitted.

Examples of the invention An embodiment of this invention will be described based on the drawings.

The housing (11 has a print head (2) and a carrier (3) mounted thereon, and a carrier shaft (4) and a guide shaft (5).
) and can be held and slid freely. A cover (6) is provided on the top surface of the housing (1), although only a portion thereof is shown. The print head (2) is mounted on a guide frame (with which a mounting flange (7) is formed for the carrier (3)
8) and a magnetic case (9) connected to the guide frame (8), the guide frame (8) holds a plurality of needles (II) in a slidable manner, and the magnetic case (9) holds a plurality of needles (II) in a slidable manner. alt - Contains individually driven electromagnets (not shown).

And, on both sides of the guide frame (8), 'uLtat
Magnetic plates Q and magnetically coupled to both poles of the coil αυ are fixed, and magnetic poles I facing each other across the slit asth are bent and formed on these magnetic plates a2. These magnetic poles αa have a conical projection α that tapers toward the lower end and a guide line ae along the inner edge.

Next, an ink tank αη is removably attached to the upper part of the guide frame (8), and the upper end of the i-pole α is inserted into the lower surface of this ink tank Q7) that stores magnetic ink u81'. (4 ink supply holes communicating with 13&C are formed, and the other parts are sealed.

The width of the ink supply hole (II is determined to prevent the magnetic ink from dripping due to its own weight.) The width of the ink supply hole The dimensions are determined so that it will fall under its own weight.Furthermore,
An ink receiver (A) is provided opposite the lower end of the magnetic pole I at the home position of the carrier (3).

Next, we will explain how to supply the magnetic ink Q8 to the ink tank (131).First, the electromagnetic coil αυ is excited to form a magnetic field between the magnetic poles. Q3).At this time, the magnetic ink Q8 flows along the guide line Qe and does not scatter outside.
The magnetic ink does not reach the lower end of the upper projection α9, which is far from the electromagnetic coil aD and has a weak magnetic field.

In this state, the carrier (3) is fully moved, the electromagnet in the magnet case (9) is fully excited, and the needle (Ilt-) is driven to perform printing. That is, the needle is inserted into the slit (IJ).
The magnetic ink A8 forming a film is transferred onto recording paper.

After printing is completed, return the carrier (3) to the home position and turn off the power to the ta coil Uυ. As a result, the magnetic ink cartridge (p, sulin) (131) is guided by the guide strip αe and flows downward without protruding from both 11!l, and is further guided by the conical projection a9 to the ink receiver (2). The ink tank aη has no openings other than the ink supply hole α■, and the ink supply hole α field itself is small.
Surin) (Even if 1m becomes air pressure, a new ink tank (l)
The magnetic ink (I81) 'D will not flow out into the slit a.

In this way, the magnetic ink a8 held in the slit grating has a large contact area with the outside air and the solvent is likely to evaporate, but it is not returned to the ink tank aη but is discarded into the ink receiving part t21, so the ink tank (17) The concentration of magnetic ink Q8 does not increase. In addition, the ink tank (17
) absorbs as much air as it supplies magnetic ink 08t,
The magnetic ink Ql, which is constantly exposed to a wide range of outside air, must be kept within an extremely small area corresponding to the ink supply hole (lI).
The amount of the magnetic ink solvent in the ink tank αη that evaporates into the atmosphere is also extremely small.

Therefore, in this respect as well, the density of the magnetic ink does not become high, and the printing density can be made uniform throughout.

Further, the level of magnetic ink α in the ink tank aD during printing decreases according to the amount consumed, but as long as magnetic ink a8 exists inside, it is supplied to the ink tank aD (131).

Therefore, there is no need to separately provide an additional ink tank for replenishment in order to keep the magnetic ink level of the ink tank (Lη) constant.

In addition, as shown in FIG. 8, by forming the magnetic pole a (slanted edge aI) i, for example, by increasing the total length of the magnetic path for the electromagnetic coil (11) toward the bottom of the slit (131), Figure 9: Slit Q□□
□By keeping the film thickness of the magnetic ink barrel constant over the entire area, it is possible to eliminate the difference in printing density between the upper and lower sides of a single character.

Effects of the Invention Since the present invention is configured as described above, the magnetic ink in the slit can be moved downward after printing, and the evaporation of the solvent of the magnetic ink in the ink tank into the atmosphere can be reduced. It is possible to print with no difference in density by minimizing the degree change, and by supplying magnetic ink from the top of the slit, the consumption of magnetic ink progresses and the level of magnetic ink in the ink tank decreases. Even if the magnetic ink changes, a certain amount of magnetic ink can be supplied to the slit at a certain level, and this has the effect that an ink tank for replenishing the ink can be omitted.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view of the entire configuration with a reduced size and a portion cut away, FIG. 2 is a perspective view of the print head, and FIG. 3 is a plan view thereof. Fig. 4 is a side view thereof, Fig. 5 is a front view thereof, Fig. 6 is a front view of the ink tank in cross section showing the state of connection between the ink tank and the slit, Fig. 7 is a plan view of the magnetic poles, and Fig. 7 is a plan view of the magnetic poles. Figure 8 is a front view of a modified example of the magnetic pole. lO... Needle, 11... Electromagnetic coil, 13...
・Slit, 14...ik, u...ink tank,
18...Magnetic ink, 19...Ink supply hole 15 diagram"■Commercial"6 flash 0 country"5

Claims (1)

[Claims] A pair of magnetic poles facing each other with a slit through which multiple needles pass is 1! An ink supply hole which is magnetically coupled to both poles of a magnetic coil and communicates with the upper part of the slit in a sealed ink tank containing magnetic ink is formed with a size determined to prevent the magnetic ink from dripping under its own weight. Then, the electromagnetic coil is energized to form a magnet between the magnetic poles, all of the magnetic ink of the ink tank is attracted to the slit, and the magnetic ink forming a film in the slit is exposed to the knee.
This magnetic ink is transferred to the recording paper by penetrating it,
1 after printing is completed! A method for supplying magnetic ink for a dot printer, characterized in that the flow rate to the magnetic coil is completely cut off, and only a portion of the magnetic ink held in the slit is dropped at t'.