JPS6229235B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink supply device for a wire dot printer, whether it is 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, at least when not printing, the ink supply is reduced to prevent the ink from evaporating and causing clogging, making it impossible to supply the ink. This invention relates to an ink supply device for a wire dot printer that stops the ink supply 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 for the ribbon becomes an impediment to miniaturization of the printer, increasing the cost of the mechanical part and the running cost.

There are too many to list.

The 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 guide, 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 both methods.To avoid duplication, we will use the serial method from now on. We recommend that the explanation be limited to the following.

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 applied 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, when the ink is left unused, the replenishment of ink is stopped, and by constantly replenishing the evaporating solvent, the ink concentration in the ink reservoir is kept constant and a concentration effect does not occur.

Next, two embodiments will be described.

FIG. 3 illustrates means for supplying ink to the tip of a wire to explain one 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 fiber or porous material, which can be impregnated with liquid ink. Reference numeral 304 refers to the supply of ink to the wire guide ink reservoir at the rear, which will be described later. It adheres to the parts. 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, the jewel ruby wire guide has a weak affinity and cannot transfer enough ink to the wire tip.
Good results can be obtained with materials that have strong affinity (such as plastics).

4 and 5 show one embodiment of the present invention. 4
01 is a wire, 402 is a wire guide, 403 is an ink reservoir, and 404 is a case, which is attached to the wire dot head. A switching valve 405 is provided inside the case, and a coil spring 410 and a push rod 411 are provided inside the valve. Ink is ink tank 4077
It communicates with the switching valve 405 via a pipe 406. Further, the ink solvent is communicated from the solvent tank 409 to the switching device via a pipe 408. Both the ink and the solvent are kept under a slight supply pressure against the ink reservoir. Further, a stopper 412 having a spring is provided on the printer frame.

When the printer prints, the wire dot head moves left and right along the paper surface, but the switching valve 405
The spring 410 allows ink to flow into the ink reservoir, and ink is supplied to the tip of the wire as described above. When not printing, or at least when leaving it for a long time, it should be left in the state shown in Fig. 5. That is, the wire dot head is stationary at the right end and the switching valve is switched by stopper 412 to supply solvent to the ink reservoir. The switching valve and the stop therefore form a switching device. Ink is shut off by a switching valve, and only solvent is supplied to the ink reservoir. While the wire is left standing, the ink solvent evaporates from the tip of the wire and other parts, but the solvent is replenished accordingly. Since ink is not newly replenished, the ink concentration in the ink reservoir remains almost unchanged from its initial state, and therefore the tip of the wire is always kept moist and ready to resume printing at any time. Next, when printing is started again, the state shown in FIG. 4 is returned, and only the amount of ink that has been used is replenished from the ink tank.

Next, another embodiment of the present invention will be described with reference to FIG.

The ink reservoir is divided into two, a first ink reservoir and a second ink reservoir. The first ink reservoir 601 is located at the same location as in the first embodiment and has the same function. A second ink reservoir 602 can be impregnated with fibrous or porous ink in the same way as the first ink reservoir. The container 603 has an opening 6
04, and can slide left and right within the cavity 605,
It is normally pushed to the left by a spring 606. The switching device valve is a switching valve 607 and a coil spring 608.
and a solenoid 609. The second ink reservoir 60 is activated by energizing the solenoid 609.
Ink is supplied to 2. Also, the switching valve 607
An ink pipe 610 and a solvent pipe 611 are attached to the ink pipe 610 and a solvent pipe 611 to supply ink or solvent to the second ink reservoir 602 through a hole 621 provided in the case 620. The case 620 and its contents are fixed to the printer case portion and do not move. The operation in this embodiment is as follows. Solenoid 6 when printing
09 is energized, the switching device is placed in a position where ink is supplied, and ink is supplied to the second ink reservoir 602. During printing, the wire dot head 600 moves left and right along the paper surface. For example, the first ink reservoir 601 is brought into contact with the second ink reservoir 602 at the rightmost end. At this time, the first ink reservoir 601 receives ink from the second ink reservoir 602 moistened with ink. The amount must be sufficient to supply enough ink to the wire tip 612 for at least one reciprocation of the wire dot head 600. wire dot head 60
0 is printed, goes back and forth once, and returns to the first ink reservoir 6
Printing is performed using only the ink in the first ink reservoir 601 until 01 and the second ink reservoir 602 come into contact and receive ink supply. Next, if you want to leave it for a long time without printing, use the wire dot head 600.
is located at the rightmost end, and the first ink reservoir 601 and the second ink reservoir 602 remain in contact with each other. The solenoid 609 is de-energized and the second ink reservoir 602 is supplied with solvent. It will be understood from the above explanation that the evaporated portion of the solvent can be replenished in this state.

In the second embodiment, the second ink reservoir 6
Even if the ink supply of No. 02 is not so strict, there is a great advantage that the ink supply to the first ink reservoir 601 is stable. Further, in this embodiment, the ink reservoir has been described as being divided into two, the first ink reservoir 601 and the second ink reservoir 602, but a combination of the two is also possible, which limits the scope of the claims. isn't it.

Further, another embodiment of the present invention, which is a partially modified version of FIG. 6, will be described with reference to FIG. 7. The same numbers as in FIG. 6 have the same meanings and operations, and their explanations will be omitted here.During normal printing, the switching valve 607 is operated by a spring 613 so that ink is supplied by the ink pipe 610. being pushed to the left. This switching valve 607 only moves when the wire dot head 600 moves to the rightmost position, and normally ink is supplied to the second ink reservoir 602.

Next, if you want to leave it for a long time without printing, move the wire dot head 600 to the rightmost position and
The second ink reservoir 601 and the second ink reservoir 602 remain in contact with each other. At this time, the protrusion 614 provided on the wire dot head 600 moves the switching valve 607 to the right by overcoming the spring force of the spring 613, and the second ink reservoir 602
It will be understood that the solvent is supplied through the solvent pipe 611, and even if the solvent at the wire tip 612 evaporates, the solvent pipe 611 can sufficiently replenish the evaporated solvent.

As is clear from this example, the method of omitting the ribbon of a wire dot printer and attaching ink directly to the tip of the wire solves the technical problems associated with conventional ink ribbons, regardless of the newness of the ribbon. This provides uniform quality printing. 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. Further, although the structure of the ink reservoir and the means for switching and supplying ink and solvent to the ink reservoir have been illustrated in the embodiment, they are not limited to this embodiment.

As described above, according to the present invention, while the wire dot head is being transferred by the transfer means, the ink supply path is opposed to the ink reservoir, and the wire dot head is moved to a predetermined stop position by the transfer means. When the solvent is transferred to the wire, the switching means switches the solvent supply path so that it faces the ink reservoir, so when printing, a certain amount of ink necessary for printing is supplied to the tip of the wire, so the amount of ink is reduced. Problems caused by excess or deficiency will be resolved.

When the wire dot head is stopped at a predetermined stop position, the solvent prevents the ink in the ink reservoir from condensing, and the ink reservoir is moistened by the solvent, so that the wire tip is also moistened. Since the wire is not wetted with the wetted ink and is not brought into close contact with the wire guide, the wire does not become inoperable.

[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. FIG. 3 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 an embodiment of the present invention. 4
03 is an ink reservoir, 405 is a switching valve, 407
indicates an ink tank, and 409 indicates a solvent tank. FIG. 5 is a diagram showing the state of one embodiment of the present invention when left unattended. FIG. 6 is a diagram showing another embodiment of the present invention. 601 is a first ink reservoir, 602 is a second ink reservoir, and 607 is a switching valve. FIG. 7 is a diagram showing an embodiment in which the other embodiment of the present invention shown in FIG. 6 is partially modified.

Claims (1)

[Scope of Claims] 1. A wire in which an ink reservoir provided near the tip of the wire supplies ink to the tip of the wire by capillary action, and the tip of the wire is selectively brought into contact with printing paper during printing. The dot printer includes: a wire dot head in which a plurality of wires are arranged in a row; an ink reservoir made of a porous member that contacts near the tip of the wire; and an ink supply section that supplies ink from an ink tank to the ink reservoir. , a solvent supply path for supplying the solvent in the solvent tank to the ink reservoir; and controlling the wire dot head so that the wire dot head prints dots of one line of characters, symbols, or figures along the printing paper. a transport means for moving the ink along the printing paper, and during transport during which the wire dot head is transported by the transport means, the ink supply path is opposed to the ink reservoir, and the wire dot head is moved along the transport means. switching means for switching the solvent supply path to face the ink reservoir when the solvent is moved to a predetermined stop position by the means;
An inking device for a wire dot printer, comprising: