JPS6048393A - Printing apparatus - Google Patents

Abstract

PURPOSE:To prevent the lowering in printing quality, by providing a ribbon holding member for energizing an ink ribbon to the direction of printing paper through a ribbon shield, and bringing a printing wire into contact with the ink ribbon only at the time of impact. CONSTITUTION:A ribbon holding member 7 is energized to the side of printing paper 5 by a spring and keeps such a state that an ink ribbon 1 is always pressed to the direction of a platen 4 through a ribbon shield 6. A printing head 2 moves to a direction shown by the arrow S and a printing wire 3 is contacted with the ink ribbon 1, which is energized to the printing paper 5, only at the time of impact by the ribbon holding member 7 and is not contacted therewith during flight.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a dot matrix type serial printer that prints on printing paper via an ink ribbon, and in particular, the present invention relates to a dot matrix type serial printer that prints on printing paper via an ink ribbon. This invention relates to a printing device whose reliability is improved by limiting the number of printing devices.

[Background of the invention]

In the conventional impact-type serial dot matrix printer, as shown in FIG. 1, the ink ribbon 1 is always in contact with the tip of the print head 2 due to the tension T generated by the winding mechanism. Therefore, as shown in FIG. 2, the print wire 3 of the print head 2 is always in contact with the ink ribbon l from the start to the end of the operation, and the relative relationship between the ink ribbon 1 and the print head 2 is Due to the speed difference V, the printing wire 3 is subjected to a lateral pressure F, which causes the printing wire 3 to become unstable, resulting in a decrease in printing quality. The influence of the lateral pressure of the ink ribbon 1 on the printing wire 3 as described above becomes more pronounced as the printing speed becomes faster and as the distance between the print head 2 and the platen 4 or the printing paper 5 becomes larger.

In addition, in the above-mentioned conventional printing device, if printing is performed while the distance between the print head 2 and the platen 4 is incorrectly set large, the printing wire 3 may be connected to the ink ribbon.
There is also the problem that the printing wire 3 gets caught in the paper, causing problems such as breakage and deformation of the printing wire 3. In order to solve this problem, it may be possible to provide a mechanism that automatically sets the distance between the print head 2 and the platen 4 to the minimum distance, but this raises other problems such as making the printer expensive. This will result in

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to solve the above-mentioned problems in conventional printing devices, and to provide a simple configuration capable of high-quality printing and highly reliable printing. The goal is to provide equipment.

[Summary of the invention]

The above object of the present invention is to bias the ink ribbon in the direction of the printing paper via the ribbon shield in a donmatrix type serial printer in which the print head prints on the printing paper via the ink ribbon while moving parallel to the platen. This is achieved by a printing device characterized in that a ribbon holding member for holding the ink ribbon is provided so that contact between the printing wire and the ink ribbon is limited to only at the time of impact.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a side view showing the main parts of a printing device which is an embodiment of the present invention. In the figures, symbols 1 to 5 refer to figures 1 and 2.
The same components as shown in the figure are shown; 6 is a ribbon shield for preventing the ink ribbon 1 from unnecessarily contacting the printing paper 5; 7 is a ribbon holding member which is the main part of this embodiment; 8 indicates a career.

The ribbon shield 6 and ribbon holding member 7 are fixed to the carrier 8 for moving the print head 2 parallel to the platen 4. In addition, the ribbon holding member 7
has a spring property such that it is biased in the direction of arrow P. As a result, the ribbon shield 6 and the ribbon holding member 7 can be held together even when tension is applied by the ribbon winding mechanism.
It is possible to maintain the state in which the ink ribbon 1 is pressed against the platen 4, and the configuration is such that a gap G exists between the ink ribbon 1 and the print head 2.

The operation of this embodiment configured as described above is shown in Fig. 4 (A
) to (C).

Figures 4 (A) to (C) schematically show the printing operation; (A) shows the state before printing starts, (B) shows the state immediately after printing starts, and (C) shows the state immediately after printing starts. indicate the moment of printing. Arrow S indicates the direction of movement of the print head 2. As described above, the ink ribbon 1 is urged in the direction of the printing paper 5 by the ribbon holding member 7, so as shown in FIGS. 4(A) to 4(C), the printing wire 3
contacts the ink ribbon l only at the time of impact (C), and not during flight (B).

Therefore, according to this embodiment, the lateral pressure F as described above is not applied, and the reciprocating movement of the printing wire 3 is performed smoothly without being disturbed by the ink ribbon 1, thereby improving printing quality. In addition, deformation and breakage of the printing wire 3 are eliminated.
Improved reliability.

Moreover, since the mechanism is simple, the price increase of the printing device is extremely small.

FIG. 5 shows a case where the printing paper 5 is thick and the distance between the print head 2 and the printing paper 5 is small in the apparatus of the embodiment shown in FIG. Further, FIG. 6 shows a case where the distance between the print head 2 and the platen 4 is erroneously set too large. In any of the above cases,
Due to the springiness of the ribbon holding member 7, the ink ribbon 1 is held at a position apart from the printing ped 2, and the printing wire 3 and the ink ribbon l do not come into contact except at the time of impact.

FIG. 7 shows a second embodiment of the present invention, in which the springiness of the ribbon holding member 7 is provided by an external spring 9 via a pivot 1-10 provided on a carrier 8. It is.

8 and 9 show other embodiments of the present invention, FIG. 8 shows an example in which the ribbon shield 6 and the ribbon holding member 7 are fixed to the print head 2, and FIG. An example is shown in which the shield 6 is fixed to the carrier 8 and the ribbon holding member 7 is fixed to the print head 2 separately.

FIG. 10 shows yet another embodiment of the present invention,
This shows an example in which a ribbon shield 6 is fixed to a carrier 8 and a ribbon holding member 7 is provided in an ink ribbon cassette 11. In this case, there is an advantage that the structure of the printing device becomes simpler.

In the apparatus of the embodiment shown in FIGS. 7 to 10, as well as the apparatus of the first embodiment shown in FIGS. 3 to 6,
It goes without saying that the effects of the present invention can be fully exhibited.

In each of the above embodiments, an example is shown in which the ribbon holding member 7 has spring properties in order to urge the ink ribbon 1 toward the platen 4. However, the above spring properties apply only to the ribbon holding member 7. Needless to say, it is also possible to have Ribbon Shield 6 have it instead.

〔Effect of the invention〕

As described above, according to the present invention, in a nodal matrix serial printer in which the print head prints on printing paper via an ink ribbon while moving parallel to the platen, the ink ribbon is printed via the ribbon shield. A ribbon holding member is provided to hold the ink ribbon so as to move in the direction of the paper, and the contact between the printing wire and the ink ribbon is limited to the first ink ribbon, thereby stabilizing the operation of the printing wire. This has the remarkable effect of making it possible to prevent deterioration in print quality and realizing a highly reliable printing device.

[Brief explanation of drawings]

Figures 1 and 2 are plan views showing the conventional printing mechanism;
5 and 6 are side views showing a printing mechanism which is an embodiment of the present invention, FIGS. 4A to 4C are plan views schematically showing its operation, and FIGS. FIG. 9 is a side view showing another embodiment of the present invention, and FIG. 10 is a plan view thereof. I: ink ribbon, 2: print head, 3: print wire,
4 Nibraten, 5: Printing paper, 6: Ribbon shield, 7
: ribbon holding member, 8: carrier, 11: ink ribbon cassette. Figure 1 Figure 2 Figure 3 Figure 4 Figure CA) Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Same figure] O figure

Claims (1)

[Claims] (1) In Dosotoma 1-RiX type serial printers, in which the print head moves parallel to the platen and prints on the print paper via the ink ribbon, the ink ribbon is urged toward the print paper via the ribbon shield. A printing device comprising a ribbon holding member that holds the ink ribbon.