JPH0649386B2 - Thermal ink ribbon for thermal transfer printer - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a thermal ink ribbon which is an ink ribbon used in a thermal transfer printer.

[Technical Background of the Invention and Problems Thereof] There are two types of thermal printers, a thermal printer using thermal paper and a thermal transfer printer. The thermal transfer printer has an advantage of printing on plain paper by using a thermal ink ribbon. In this thermal transfer printer, a thermal head (that is, a print head), which is a heating element, presses the thermal ribbon toward the platen side, and the ink melted by the heat generated by the thermal head is transferred to a sheet for printing.

Here, as shown in FIG. 3, the thermal ink ribbon is composed of a release layer 11 and an ink layer 12 formed on a base 10 of a polyester film. The peeling layer 11 is made of, for example, paraffin wax. The ink layer 12 is made of a pigment such as toluene solvent and carbon black. As shown in FIG. 4, when the thermal head 13 contacts and presses against such a thermal ink ribbon, the heat of the thermal head 13 causes a part of the ink layer 12 to melt from the peeling layer 11. It is peeled off and transferred to the surface of the paper 14.

By the way, the surface of the paper 14 has considerably different smoothness depending on the type of paper. Paper with low smoothness has severe surface irregularities,
It has a so-called rough surface. When such a paper with low smoothness is used, the ink of the ink layer 12 is not sufficiently transferred to the surface of the paper, and the print quality deteriorates. In order to eliminate such a point, a method in which the pressing force of the thermal head 13 is increased and the thermal ink ribbon is strongly pressed onto the paper 14 to temporarily increase the smoothness of the paper 14 during the printing operation. Can be considered. However, the thermal head
When the pressing force of 13 is increased, there are problems that the running trouble of the thermal ink ribbon is likely to occur and the life of the thermal head 13 is shortened.

[Object of the Invention] The object of the present invention is to provide a paper having a relatively low smoothness,
It is an object of the present invention to provide a thermal ink ribbon for a thermal transfer printer that can reliably transfer the required ink without requiring a large pressing force of the thermal head and can realize high printing quality.

SUMMARY OF THE INVENTION The present invention is a thermal ink ribbon comprising a film base, a release layer and an ink layer, wherein the release layer is a layer containing a low boiling point material in a liquid state at room temperature.

In this way, the thermal ink ribbon vaporizes the low-boiling-point material of the release layer due to the heat generated by the thermal head, and the pressure generated at this time makes it possible to strongly push the melted ink from the ink layer toward the paper.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1 is a sectional side view showing the structure of a thermal ink ribbon according to an embodiment. As shown in FIG. 1, the thermal ink ribbon has a three-layer structure including a base 10, a peeling layer 20, and an ink layer 12. The base 10 is made of a polyester film. The release layer 20 is formed on the base 10. The peeling layer 20 contains, for example, paraffin wax as a main component, and contains a low boiling point material 21 in a liquid state at room temperature therein. The low boiling point material is, for example, ethyl tetrachloride (C ₂ H ₂ Cl ₄ ). The ink layer 12 is composed of, for example, a solid-phase toluene solvent or a pigment such as carbon black at room temperature.

Next, the function and effect of the embodiment will be described. When the thermal ink ribbon shown in FIG. 1 is used in a thermal transfer printer, printing is performed by the following operation. First, second
As shown in the figure, the thermal ink ribbon is set so that the ink layer 12 contacts the paper 14 held by the platen (not shown). The thermal head 13 contacts the base 10 of the thermal ink ribbon, and the thermal head 13 presses the thermal ink ribbon from the base 10 side to the paper 14 side with a constant pressing force. As a result, the ink layer 12 of the thermal ink ribbon comes into contact with the surface of the paper 14 so as to be pressed against it.

In this state, when the thermal head 13 generates heat, the base 10
The peeling layer 20 and the ink layer 12 are heated through. In a part of the peeling layer 20 according to the contact area of the thermal head 13, when the temperature reaches a predetermined value (boiling point of the low boiling point material 21), the low boiling point material 21 contained in the peeling layer 20 changes to a gas 22. . Due to the vaporizing action of the low boiling point material 21, a part of the volume of the peeling layer 20 expands. Therefore, the pressure around the vaporized portion increases as the volume expands. On the other hand, a part of the ink layer 12 (a portion corresponding to the contact area of the thermal head 13) is melted by heating, and the melted ink 12a is separated from the separation layer 20. Here, since the ink layer 12 other than the melted ink and the base 10 are solid phases, the pressure due to vaporization generated in a part of the peeling layer 20 is a force for pressing the melted ink 12a toward the paper 14 side. To work. As a result, the melted ink 12a is transferred to the surface of the paper 14 so as to be peeled from the peeling layer 20 and pressed.

In this way, when the thermal head 13 presses and generates heat, the low boiling point material 21 contained in the peeling layer 20 is vaporized, and the ink layer
Part of 12 melts. At this time, the molten ink 12a is peeled from the peeling layer 20 and transferred to the surface of the paper 14 so that the melted ink 12a is pressed to the paper 14 side by the pressure due to the vaporization of the low boiling point material 21. Therefore, even if the surface of the paper 14 is a rough surface with relatively low smoothness, the ink 12a is reliably transferred to the surface of the paper 14. That is, the ink 12a is transferred to all the uneven portions on the surface of the paper 14.

In this case, since the pressure due to the vaporization of the low boiling point material 21 contained in the peeling layer 20 has a large effect on the transfer of the ink 12a, it is not necessary to particularly increase the pressing force of the thermal head 13 against the thermal ink ribbon.

[Effects of the Invention] As described in detail above, according to the present invention, in the thermal transfer printer, the melted ink can be reliably applied to the surface of the paper having a relatively low smoothness without particularly increasing the pressing force of the thermal head. Can be transferred to. Therefore, it is possible to obtain high print quality even on a sheet having a relatively low smoothness. Moreover, since it is not necessary to particularly increase the pressing force of the thermal head, the driving force of the thermal head can be reduced. Therefore, as a result, it is possible to obtain the effects that the power consumption of the printer is reduced and the printing operation is speeded up by improving the moving speed of the thermal head.

[Brief description of drawings]

FIG. 1 is a sectional side view showing the structure of a thermal ink ribbon according to an embodiment of the present invention, FIG. 2 is a sectional side view for explaining the function and effect of the same embodiment, and FIGS. FIG. 6 is a cross-sectional side view for explaining a conventional thermal ink ribbon. 10 …… Base, 11, 20 …… Release layer, 12 …… Ink layer, 13
…… Thermal head, 14 …… Paper, 21 …… Low boiling point material.

Claims (1)

[Claims] 1. A base comprising a film, a release layer formed on the base and containing a low boiling point material in a liquid state at room temperature, and an ink layer formed on the release layer. A thermal ink ribbon for a thermal transfer printer.