JPS637952B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink supply device for a wire dot printer, whether a serial printer or a line printer.

In other words, in a printing method in which liquid ink is attached to the tip of a wire and printed directly on the paper surface, solid ink is used at least when not printing to prevent ink from evaporating and causing clogging, making it impossible to supply the paper. This invention relates to an ink supply device for a wire dot printer that uses liquid ink and a solvent to dissolve solid ink as necessary to produce liquid ink, and when not printing, stops producing liquid ink and supplies only the evaporated solvent.

Wire dot printers used as peripheral terminal devices are broadly classified into serial type and line type. In either method, wire dot printers use ink ribbons, but ink ribbons have many technical and handling problems, and the solution to these problems is to print by applying liquid ink directly to the tip of the wire. It is an object of the present invention to provide a method.

Some of the problems with ink ribbons are as follows: (1) The ribbon fabric is torn because the ribbon is hit with the tip of a thin wire (about 0.35φ), and the wire may get caught in this tear or break.

(2) The ink density of the ribbon gradually decreases during use, making it impossible to maintain a constant print quality.

(3) Ribbons impair the ease of inserting paper and have poor operability, such as the paper getting caught when feeding the paper.

(4) The space occupied by the ribbon becomes an impediment to miniaturization of printers, increasing mechanical costs and running costs.

There are too many to list.

An object of the present invention is to eliminate these technical and handling disadvantages of ink ribbons.

The high impact energy of the wire leads to increased heat generation due to the input electrical energy and wear of the wire drive section, which has a significant impact on the reliability of the dot head. An object of the present invention is to improve the reliability of a wire dot head by reducing the impact energy of the wire by striking ink directly onto the paper surface without using a ribbon.

There are many factors that determine the print quality of a printer.
The biggest change is in the density of the ink ribbon. By the time the ink ribbon finally runs out and the ink ribbon has to be replaced, the ink density will gradually decrease and the print quality will deteriorate. Another object of the present invention is to maintain print quality with constant ink density from beginning to end.

In this method, in which ink is directly attached to the tip of the wire, when the printer is not in use, the ink evaporates and condensed ink accumulates at the tip of the wire, resulting in a so-called clogging condition, which eventually makes it impossible to supply ink. Still another object of the present invention is to provide an inking system that does not cause clogging.

FIG. 1 conceptually illustrates a serial wire dot printer according to the present invention.

1 is a printing paper, 2 is a print head consisting of a plurality of wires (generally 7 or 9 wires), 3 is a wire guide, and 4 is a wire. 5 is an ink reservoir that supplies ink to the tip of the wire. A soft material made of fibers or porous material is impregnated with liquid ink, and the ink is adhered to the tip of the wire by surface tension or capillary action. When the wire is driven by an electrical signal, the tip of the wire strikes the printing paper and transfers the ink. Unlike conventional printers, no ink ribbon is required.

FIG. 2 is a conceptual diagram of a line type wire matrix printer according to the present invention.

11 is a printing paper, 12 is a solenoid, 13 is a wire, and 14 is a wire. 15 is an ink reservoir similar to that shown in FIG. Each wire is selectively driven while vibrating horizontally, and selectively driven while vibrating vertically, moving the paper vertically one dot at a time in small increments to form a pattern. The method of supplying ink to the tip of the wire is the same as the serial method shown in FIG.

The only difference between these two methods is whether the number of wires is multiple or one, and the method of supplying ink to the tip of the wire is the same in either method.To avoid duplication, the serial I recommend limiting the explanation to the formula.

This ink supply means can be easily realized not only by the method of this embodiment but also by other methods. This is because if ink is attached to the vicinity of the tip of the wire by some method, the ink will diffuse to the tip of the wire by itself due to capillary action and surface tension.

The next issue is how to supply ink to this ink reservoir. If ink is simply supplied and left for a long time, the ink in the ink reservoir will gradually evaporate and become concentrated. Eventually, it becomes solid ink and becomes clogged, making it impossible to supply ink to the tip of the wire.

The present invention solves this problem as follows. That is, solid ink is brought into contact with an ink reservoir containing a solvent as needed and dissolved in the solvent in the ink reservoir to produce liquid ink. By cutting off the contact between the solid ink and the ink reservoir to stop the dissolving action and constantly replenishing only the evaporating solvent, the ink concentration in the ink reservoir can be kept constant and the concentration effect can be prevented. be.

Next, two embodiments will be described.

FIG. 3 illustrates a means for supplying ink to the tip of a wire to explain an embodiment of the present invention.

301 is a wire, 302 is a wire guide, 30
3 is a soft sponge-like ink reservoir made of fibrous or porous material, which can be impregnated with liquid ink. 304 is a wire guide at the rear, and the ink supply to the ink reservoir will be described later; the ink supplied to the ink reservoir is transferred to the wire 3.
The ink adheres to the tip of the ink by capillary action through the gap between the ink and the wire guide or the gap between the wire guide and the ink. Further, it is necessary that the surface of the wire and the wire guide have sufficient affinity with the ink.
For example, when using the above ink, a wire guide made of gemstone ruby has a weak affinity and cannot transfer sufficient ink to the tip of the wire, whereas a wire guide with a strong affinity (for example, plastic, etc.) yields good results.

4 and 5 show a first embodiment of the present invention. Reference numeral 400 indicates the entire print head, which is a portion that moves along the paper surface during printing. 401 is a wire, 402 is a wire guide, and 406 is a first ink reservoir. The solvent is impregnated into the second ink reservoir 403 from the solvent tank 404 via the pipe 405. The second ink reservoir 403 is made of a spongy or fibrous material like the first ink reservoir 406, and has a structure in which it can be pushed in somewhat by a spring 407. The solid ink 408 is placed in a position where its tip is recessed from the tip of the second ink reservoir 403, and when the tip of the solid ink 408 melts, it is pushed out by a spring 409 and the solid ink 4
The tip position of 08 is always secured.

Now, when the print head 400 prints in this apparatus, the printing is performed using the ink impregnated in the first ink reservoir 406.

So, how do we fill the first ink reservoir 406?
The way to supply liquid ink to is as follows. First, the print head 400 moves to the moving means 41.
Closer to the right edge by 0 (first position), the fifth
The state shown in FIG. 5A is reached (actually, the state shown in FIG. 5A is a state in which printing is not performed and is left unused), and the first ink reservoir 406 and the second ink reservoir 403 come into contact. Further, when the moving means 410 moves one step to the right (second position), the state shown in FIG. 5b is reached, and the first ink reservoir 4
06 contacts both the second ink reservoir 403 and the tip of the solid ink 408. In this state, the solvent flows from the second ink reservoir 403 to the first ink reservoir 403.
At the same time, the solvent in the first ink reservoir 406 dissolves the leading end of the solid ink 408 and stores it in the first ink reservoir 406 as liquid ink. This contact time must be selected to suit the usage conditions of the printer. The ink is kept in the first ink reservoir 4 until the print head 400 makes one reciprocation while printing next time.
06 is used.

Now, if the printer is left in a non-printing state, it will be in the state shown in FIG. 5a. That is, the first ink reservoir 4
06 is in contact with the second ink reservoir 403, but not in contact with the solid ink 408 (the first
Position of). Therefore, the dissolution of the solid ink 408 is stopped, and only the amount of solvent that evaporates from the first ink reservoir 406 is replenished from the second ink reservoir 403 by capillary action. First ink reservoir 406
Since the amount of ink does not change during this time, the density may be diluted but never thickened, and clogging due to the concentration effect does not occur. Furthermore, since the first ink reservoir 406 is always in a wet state, it is always ready for printing.

The basic principle is the same as that of the first embodiment, and various combinations are possible, which will be shown below.

FIG. 6 shows a second embodiment. 601 is the first
602 is a second ink reservoir, 60
3 is solid ink. The usage method can be easily inferred from the first embodiment, so it will be omitted, but in this embodiment, liquid ink is produced in the second ink reservoir 602, and this is transferred to the first ink reservoir. If you leave it alone when not printing, use the first ink reservoir 60.
The first and second ink reservoirs 602 are in contact with each other, and the second ink reservoirs 602 and solid ink 603 are not in contact with each other.

Next, a third embodiment is shown in FIG. A shows a state in which the ink reservoir 701 and solid ink 703 are separated, and b shows a state in which the ink reservoir 701 and solid ink 703 are in contact with each other. In the ink reservoir 701,
A solvent is constantly supplied from a solvent tank 702. Only solid ink 703 is fixed at another location.

When print head 700 reaches the right end, ink reservoir 701 contacts solid ink 703 to produce liquid ink. If you leave it alone when not printing,
When the ink is left in the position where this contact is cut off, the ink production process stops and only the solvent replenishes the evaporated content, preventing clogging.

As is clear from the examples, the method of omitting the ribbon of a wire dot printer and applying ink directly to the tip of the wire solves the technical problems associated with conventional ink ribbons, and can be applied uniformly regardless of the newness of the ribbon. It provides high-quality printing quality. This method also has many of the advantages mentioned above. In particular, it is highly effective in solving problems caused by ink ribbons in conventional printers and improving reliability. The wire drive mechanism requires less wire impact energy because the ribbon runs out, and there is no upper limit to the wire energy because there is no risk of ribbon breakage.In other words, the wire impact energy can vary widely. This made adjustment easier, extended the lifespan, and increased reliability. Additionally, since the space occupied by the ribbon is no longer required, it is possible to downsize the printer and reduce costs. There have been attempts to apply ink directly to the tip of the wire, but it has never been put to practical use. It could only be put into practical use after the development of ink with low viscosity and low surface tension, and the completion of measures to prevent drying.

Although this embodiment has been exemplified in the case of a serial type wire dot printer, it is of course applicable to line type wire dot printers, and can be widely applied to other wire type dot printers. Further, the means for supplying ink from the ink reservoir to the tip of the wire is not limited to that shown in this embodiment, and for example, the ink reservoir may be brought into contact with the wire intermittently.

As described above, according to the present invention, when not printing,
The contact between the ink reservoir and the solid ink is broken to supply only the solvent from the solvent supply means to the ink reservoir, and during printing, the solid ink is connected to the ink reservoir in order to dissolve the solid ink and replenish the liquefied ink to the ink reservoir. Since the wire dot head is transferred by the transfer means so as to be in contact with the ink, the solvent is supplied into the ink reservoir during non-printing, so that condensation of the ink in the ink reservoir can be prevented.
Furthermore, since the ink reservoir is moistened with the solvent, the tip of the wire is also moistened with the moistened ink, and the wire adheres closely to the wire guide, etc., so that the wire does not become inoperable. During printing, a certain amount of ink required for printing can be produced by bringing the ink reservoir into contact with the solid ink, so that a constant supply can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a serial type wire dot printer of the present invention provided with an ink reservoir 5. As shown in FIG. Second
The figure is a schematic diagram of a line type wire dot printer of the present invention provided with an ink reservoir 15. Figure 3 shows
FIG. 2 is a configuration diagram of a means for supplying ink to the tip of a wire for explaining an embodiment of the present invention. 303 is an ink reservoir. FIG. 4 is a diagram showing a first embodiment of the present invention. 403 is a first ink reservoir, 406 is a second ink reservoir, and 408 is solid ink. FIG. 5 is a diagram showing the state of the first embodiment of the present invention when left unattended. FIG. 6 is a diagram showing a second embodiment of the present invention. 601 is a first ink reservoir, 602 is a second ink reservoir, and 603 is solid ink. FIG. 7 is a diagram showing a third embodiment of the present invention. 701 is an ink reservoir, and 703 is solid ink.

Claims (1)

[Scope of Claims] 1. A wire dot printer that prints by selectively bringing the tip of a wire into contact with printing paper, comprising: a wire dot head having a plurality of wires; and an ink reservoir that comes into contact near the tip of the wire. a solvent supply means connected to the ink reservoir and supplying a solvent to the ink reservoir; a solid ink that selectively contacts the ink reservoir and is dissolved by the solvent; In order to release the contact between the ink reservoir and the solid ink to supply only the solvent of the solvent supply means to the ink reservoir, and to replenish the ink reservoir with liquefied ink by dissolving the solid ink during printing. An ink supply device for a wire dot matrix printer, comprising: a transfer means for transferring the wire dot head so as to bring the ink reservoir into contact with the solid ink.