JPH01125254A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To prevent the adverse effect of printing quality upon the smoothness of paper by providing a transfer process a few times. CONSTITUTION:A heater thermally melts wax ink 2, and the wax ink is applied on a wax ink application roller 3 by means of a thickness adjustment roller 5 with a controlled application amount. A heater 4 adjusts the viscosity of wax ink 2a applied on the application roller 3. The thickness of wax ink 2a after being applied to the application roller 3 is about 5mu in the form of a solid. A thermal head 6 supplies heat to wax ink 2b through a transfer roller 7, and the in is melted and transferred to a transfer roller 7. Paper 8 is held between a thermal pressure roller 9 and the transfer roller 7. A heater 10 heats the thermal pressure roller 9, and wax ink 2d transferred to paper melts due to heat of the paper to locally smooth the unevenness of the paper 8 by pressure of the thermal pressure roller 9. A cleaner 11 removes wax ink which is not transferred from the transfer roller 7.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a transfer structure for a thermal transfer printer.

[Conventional technology]

Conventional thermal transfer printers have a structure in which wax ink on a thermal ribbon is melted by heat generated from a thermal head and the wax ink is transferred onto paper.

[Problem that the invention seeks to solve]

However, in the prior art described above, the wax ink transfer efficiency varies depending on the smoothness of the paper, and it is necessary to use paper with high smoothness, resulting in a problem of paper selectivity.

The present invention is intended to solve these problems, and its purpose is to provide a structure in which print quality is not easily affected by the smoothness of paper.

[Means for Solving the Problems] The thermal transfer printer of the present invention is characterized by providing a plurality of transfer steps.

[Effect]

According to the above configuration of the present invention, by performing the transfer step multiple times, it is possible to apply sufficient heat and pressure during final transfer to paper.

〔Example〕

The structure and features of the thermal transfer printer according to the present invention will be explained below with reference to the drawings.

FIG. 1 is a sectional view of the present invention, and FIG. 2 is a detailed sectional view of a portion of the image transferred onto paper, and is a comparison diagram between the present invention and the prior art.

(2) Heat the wax ink from step 2 with a heater to melt it.

3 is a wax ink adhesion roller, and the wax ink adhesion thickness adjustment roller 5 controls the amount of wax ink applied, and the wax ink is applied.
4 is a heater for the wax ink adhering roller, and 2a applied to the wax ink adhering roller 3 adjusts the viscosity of the wax ink. 2a is the wax ink that has been applied to the wax ink adhering roller and is solidified with a thickness of about 5 μm. A thermal head 6 applies heat to the wax ink 2b through a transfer roller 7. The wax ink 2b is melted and transferred due to the difference in adhesive force between the wax ink adhesion roller 3 and the transfer roller 7.

2c is wax ink that has been primarily transferred to the transfer roller 7 and is in a solid state. A piece of paper 8 is held between a heating pressure roller 9 and a transfer roller 7. Reference numeral 10 is a heating and pressing roller heater that heats the heating and pressing roller 9, and as a result, the paper 8 is sufficiently heated and pressed. 2d is a wax ink transferred to the paper and is sufficiently melted by heating the paper 8, and the unevenness on the surface of the paper 8 is locally smoothed by the pressure of the heating pressure roller 9. 11 is a cleaner that removes the wax ink that has not been transferred to the paper 8 from the transfer roller 7.

FIG. 2 is a detailed cross-sectional view of a portion to be transferred to paper, in which (a) is a cross-sectional view of an example according to the present invention, and (b) is a cross-sectional view of an example according to the prior art. To supplement the above regarding (a), 7 is a transfer roller made of a highly smooth film, and heat from the thermal head 6 transfers the softened wax ink 2a to the transfer roller 7. Since the transfer roller 7 and the wax ink adhesion roller 3 are in a relatively low pressure contact state, even the softened wax ink 2a is not transferred to the transfer roller 7 other than the printed state (transfer only by pressure). The portion 20 is where the wax ink is transferred to the transfer roller by the heat of the thermal head as described above.

8 is paper with an uneven surface, but the transfer portion is smoothed and heated by a transfer roller 7 and a heating pressure roller 9. The peripheral speeds of the transfer roller 7 and the heating pressure roller 9 are the same, so even if sufficient pressure is applied to the paper, the rotational load is small. 2d is the wax ink transferred to the paper, and because sufficient heat and pressure are applied to the transfer area of the paper under the above-mentioned conditions, most of the ink is transferred to the paper.

FIG. 2(b) is a sectional view of an embodiment of the prior art, in which 6 is a thermal head, 12 is a base film of a thermal ribbon, 1
3 is wax ink, and 133 is wax ink that has been melted by the heat generated by the thermal head 6. 8 is paper with an uneven surface. A platen 14 rotates at a circumferential speed equal to the paper conveyance speed.

The thermal head 6 is fixed, and the paper 8 and the thermal ribbon 12 and 13 are held between it and the platen 14.
In order to transfer most of the wax ink 13a onto the paper, it is desirable to increase the transfer pressure to the paper 8, but since the thermal head 6 is fixed and the platen 14 rotates, increasing the pressure will cause mechanical damage. This is difficult because the load increases and wear occurs on the sliding part of the thermal head (6) with the thermal ribbon. As a result of the above, the unevenness of the paper surface in No. 8 exists even in the transfer state, and transfer variations are likely to occur (and good printing may not be possible).

〔Effect of the invention〕

According to the present invention, even when the wax ink penetrates into the paper during the final transfer to the paper, it is heated, so the wax ink does not cool down during the penetration, and the molten wax ink is transferred to the paper. almost absorbed by. Furthermore, since the peripheral speeds of the transfer roller and the heating pressure roller are equal, the rotational load is low even in the pressurized state, so sufficient pressure can be applied, and good printing with extremely high transfer efficiency can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view according to the present invention. FIGS. 2(a) and 2(b) are detailed cross-sectional views of the portion to be transferred onto paper, and are comparative views of the present invention (a) and the prior art embodiment (b). l... Heater 2... Wax ink 3... Wax ink adhesion row-7-4... Wax ink adhesion roller heater 5... Wax ink adhesion thickness adjustment roller 6... Thermal head 7. ...Transfer roller 8...Gi 9...Heating and pressure roller 10...Heater for heating and pressure roller 11...Cleaner and above Applicant Seiko Epson Corporation Figure 1

Claims (1)

[Claims] A thermal transfer printer that is characterized by having multiple transfer processes.